LTC6246, LTC6247, LTC6248 Datasheet. Www.s Manuals.com. Linear

User Manual: Marking of electronic components, SMD Codes 62, 62*, 620-015, 620-018, 620-025, 620-027, 620-0285, 620-030, 620-033, 620-035, 620-050, 620-0ER, 620-115, 620-118, 620-125, 620-127, 620-1285, 620-130, 620-133, 620-135, 620-150, 620-1ER, 6202, 6202I, 6203, 6203I, 6204, 6204I, 624, 6248, 625, 62883BHRTZ, 62883HRTZ, 62883IRTZ, 62883CHRTZ, 62883CIRTZ , 62A, 62Y. Datasheets 1.5SMC62AT3, BZV49-C62, FMMT624, FMMT625, ISL62883BHRTZ, ISL62883CHRTZ, ISL62883CIRTZ, ISL62883HRTZ, ISL62883IRTZ, LT6202CS8, LT6202IS8, LT620

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LTC6246/LTC6247/LTC6248
180MHz, 1mA Power
Efficient Rail-to-Rail
I/O Op Amps
Description

Features
n
n
n
n
n
n
n
n
n
n
n
n
n
n
n
n
n
n
n

Gain Bandwidth Product: 180MHz
–3dB Frequency (AV = 1): 120MHz
Low Quiescent Current: 1mA Max
High Slew Rate: 90V/µs
Input Common Mode Range Includes Both Rails
Output Swings Rail-to-Rail
Low Broadband Voltage Noise: 4.2nV/√Hz
Power-Down Mode: 42μA
Fast Output Recovery
Supply Voltage Range: 2.5V to 5.25V
Input Offset Voltage: 0.5mV Max
Input Bias Current: 100nA
Large Output Current: 50mA
CMRR: 110dB
Open Loop Gain: 45V/mV
Operating Temperature Range: –40°C to 125°C
Single in 6-Pin TSOT-23
Dual in MS8, 2mm × 2mm Thin DFN,TS0T-23, MS10
Quad in MS16

Applications
n
n
n
n
n
n
n

Low Voltage, High Frequency Signal Processing
Driving A/D Converters
Rail-to-Rail Buffer Amplifiers
Active Filters
Video Amplifiers
Fast Current Sensing Amplifiers
Battery Powered Equipment

The LTC®6246/LTC6247/LTC6248 are single/dual/quad low
power, high speed unity gain stable rail-to-rail input/output
operational amplifiers. On only 1mA of supply current they
feature an impressive 180MHz gain-bandwidth product,
90V/µs slew rate and a low 4.2nV/√Hz of input-referred
noise. The combination of high bandwidth, high slew rate,
low power consumption and low broadband noise makes
these amplifiers unique among rail-to-rail input/output op
amps with similar supply currents. They are ideal for lower
supply voltage high speed signal conditioning systems.
The LTC6246 family maintains high efficiency performance
from supply voltage levels of 2.5V to 5.25V and is fully
specified at supplies of 2.7V and 5.0V.
For applications that require power-down, the LTC6246
and the LTC6247 in MS10 offer a shutdown pin which
disables the amplifier and reduces current consumption
to 42µA.
The LTC6246 family can be used as a plug-in replacement
for many commercially available op amps to reduce power
or to improve input/output range and performance.
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. All other trademarks are the property of their respective owners.

Typical Application

350kHz FFT Driving ADC
0

Low Noise Low Distortion Gain = 2 ADC Driver

–20

3.3V 2.5V

VIN

VDD VREF

+
AIN

LTC6246

–
499Ω
1%

499Ω
1%
10pF

LTC2366
GND

–30
CS
SDO
SCK
OVDD
624678 TA01a

MAGNITUDE (dB)

3.3V

fIN = 350.195kHz
fSAMP = 2.2Msps
SFDR = 82dB
SNR = 70dB
1024 POINT FFT

–10

–40
–50
–60
–70
–80
–90
–100
–110

0

200

400
600
800
FREQUENCY (kHz)

1000
624678 TA01b

624678fa



LTC6246/LTC6247/LTC6248
Absolute Maximum Ratings

(Note 1)

Total Supply Voltage (V+ to V –).................................5.5V
Input Current (+IN, –IN, SHDN) (Note 2)............... ±10mA
Output Current (Note 3)...................................... ±100mA
Operating Temperature Range (Note 4).. –40°C to 125°C

Specified Temperature Range (Note 5)... –40°C to 125°C
Storage Temperature Range................... –65°C to 150°C
Junction Temperature............................................ 150°C
Lead Temperature (Soldering, 10 sec)
(MSOP, TSOT Packages Only)................................ 300°C

Pin Configuration
TOP VIEW

+IN A 3
V– 4

9

+
–

–
+

–IN A 2

7

OUT B

6

–IN B

5

+IN B

TOP VIEW

TOP VIEW

V+

OUT A
–IN A
+IN A
V–

KC PACKAGE
8-LEAD PLASTIC UTDFN (2mm s 2mm)
TJMAX = 125°C, θJA = 102°C/W (NOTE 9)
EXPOSED PAD (PIN 9) IS V–, MUST BE SOLDERED TO PCB

1
2
3
4

–
+

+
–

8

8
7
6
5

V+
OUT B
–IN B
+IN B

MS8 PACKAGE
8-LEAD PLASTIC MSOP
TJMAX = 150°C, θJA = 163°C/W (NOTE 9)

1
2
3
4
SHDNA 5
OUT A
–IN A
+IN A
V–

–
+

+
–

OUT A 1

10
9
8
7
6

V+
OUT B
–IN B
+IN B
SHDNB

MS PACKAGE
10-LEAD PLASTIC MSOP
TJMAX = 150°C, θJA = 160°C/W (NOTE 9)

TOP VIEW
–
+
+
–

+
–

16
15
14
13
12
11
10
9

TOP VIEW

OUT D
–IN D
+IN D
V–
+IN C
–IN C
OUT C

OUT 1
V– 2
+IN 3

TOP VIEW
6V

+ –

+

5 SHDN
4 –IN

S6 PACKAGE
6-LEAD PLASTIC TSOT-23

MS PACKAGE
16-LEAD PLASTIC MSOP
TJMAX = 150°C, θJA = 125°C/W (NOTE 9)

TJMAX = 150°C, θJA = 192°C/W (NOTE 9)

OUT A 1
–IN A 2
+IN A 3
V– 4

–
+
+
–

1
2
3
4
5
6
7
8

+
–

OUT A
–IN A
+IN A
V+
+IN B
–IN B
OUT B

8 V+
7 OUT B
6 –IN B
5 +IN B

TS8 PACKAGE
8-LEAD PLASTIC TSOT-23
TJMAX = 150°C, θJA = 195°C/W (NOTE 9)

Order Information
LEAD FREE FINISH

TAPE AND REEL

PART MARKING*

PACKAGE DESCRIPTION

SPECIFIED TEMPERATURE RANGE

LTC6246CS6#TRMPBF

LTC6246CS6#TRPBF

LTDWF

6-Lead Plastic TSOT-23

0°C to 70°C

LTC6246IS6#TRMPBF

LTC6246IS6#TRPBF

LTDWF

6-Lead Plastic TSOT-23

–40°C to 85°C

LTC6246HS6#TRMPBF

LTC6246HS6#TRPBF

LTDWF

6-Lead Plastic TSOT-23

–40°C to 125°C

LTC6247CKC#TRMPBF

LTC6247CKC#TRPBF

DWJT

8-Lead (2mm × 2mm) UTDFN

0°C to 70°C

LTC6247IKC#TRMPBF

LTC6247IKC#TRPBF

DWJT

8-Lead (2mm × 2mm) UTDFN

–40°C to 85°C

LTC6247CMS8#PBF

LTC6247CMS8#TRPBF

LTDWH

8-Lead Plastic MSOP

0°C to 70°C

LTC6247IMS8#PBF

LTC6247IMS8#TRPBF

LTDWH

8-Lead Plastic MSOP

–40°C to 85°C

LTC6247CTS8#TRMPBF

LTC6247CTS8#TRPBF

LTDWK

8-Lead Plastic TSOT-23

0°C to 70°C

LTC6247ITS8#TRMPBF

LTC6247ITS8#TRPBF

LTDWK

8-Lead Plastic TSOT-23

–40°C to 85°C

LTC6247HTS8#TRMPBF

LTC6247HTS8#TRPBF

LTDWK

8-Lead Plastic TSOT-23

–40°C to 125°C
624678fa



LTC6246/LTC6247/LTC6248
Order Information
LEAD FREE FINISH

TAPE AND REEL

PART MARKING*

PACKAGE DESCRIPTION

SPECIFIED TEMPERATURE RANGE

LTC6247CMS#PBF

LTC6247CMS#TRPBF

LTDWM

10-Lead Plastic MSOP

0°C to 70°C

LTC6247IMS#PBF

LTC6247IMS#TRPBF

LTDWM

10-Lead Plastic MSOP

–40°C to 85°C

LTC6248CMS#PBF

LTC6248CMS#TRPBF

6248

16-Lead Plastic MSOP

0°C to 70°C

LTC6248IMS#PBF

LTC6248IMS#TRPBF

6248

16-Lead Plastic MSOP

–40°C to 85°C

LTC6248HMS#PBF

LTC6248HMS#TRPBF

6248

16-Lead Plastic MSOP

–40°C to 125°C

TRM = 500 pieces. *Temperature grades are identified by a label on the shipping container.
Consult LTC Marketing for parts specified with wider operating temperature ranges.
Consult LTC Marketing for information on lead based finish parts.
For more information on lead free part marking, go to: http://www.linear.com/leadfree/
For more information on tape and reel specifications, go to: http://www.linear.com/tapeandreel/

Electrical Characteristics

(VS = 5V) The l denotes the specifications which apply across the
specified temperature range, otherwise specifications are at TA = 25°C. For each amplifier VS = 5V, 0V; VSHDN = 2V; VCM = VOUT = 2.5V,
unless otherwise noted.
SYMBOL

PARAMETER

CONDITIONS

VOS

Input Offset Voltage

VCM = Half Supply

MIN

TYP

MAX

UNITS

50

l

–500
–1000

500
1000

µV
µV

–2.5
–3

0.1

l

2.5
3

mV
mV

–600
–1000

50

l

600
1000

µV
µV

–3.5
–4

0.1

l

3.5
4

mV
mV

VCM = V+ – 0.5V, NPN Mode
∆VOS

Input Offset Voltage Match
(Channel-to-Channel) (Note 8)

VCM = Half Supply
VCM = V+ – 0.5V, NPN Mode

VOS TC

Input Offset Voltage Drift

IB

Input Bias Current (Note 7)

VCM = Half Supply

Input Offset Current

–350
–550

–30

350
550

nA
nA

100
0

400

l

1000
1500

nA
nA

–250
–400

–10

l

250
400

nA
nA

–250
–400

–10

l

250
400

nA
nA

VCM = Half Supply
VCM = V+ – 0.5V, NPN Mode

en

µV/°C

l

VCM = V+ – 0.5V, NPN Mode
IOS

–2

l

Input Noise Voltage Density

f = 100kHz

4.2

nV/√Hz

Input 1/f Noise Voltage

f = 0.1Hz to 10Hz

1.6

µVP-P

in

Input Noise Current Density

f = 100kHz

2.0

pA/√Hz

CIN

Input Capacitance

Differential Mode
Common Mode

2
0.8

pF
pF

RIN

Input Resistance

Differential Mode
Common Mode

32
14

kΩ
MΩ

AVOL

Large Signal Voltage Gain

RL = 1k to Half Supply (Note 10)

30
14

45

l

V/mV
V/mV

5
2.5

15

l

V/mV
V/mV

78
76

110

l

dB
dB

RL = 100Ω to Half Supply (Note 10)
CMRR

Common Mode Rejection Ratio

VCM = 0V to 3.5V

624678fa



LTC6246/LTC6247/LTC6248
electrical characteristics

(VS = 5V) The l denotes the specifications which apply across the
specified temperature range, otherwise specifications are at TA = 25°C. For each amplifier VS = 5V, 0V; VSHDN = 2V; VCM = VOUT = 2.5V,
unless otherwise noted.
SYMBOL

PARAMETER

CONDITIONS

ICMR

Input Common Mode Range

PSRR

Power Supply Rejection Ratio

VS = 2.5V to 5.25V
VCM = 1V

Supply Voltage Range (Note 6)
VOL

Output Swing Low (VOUT

– V–)

MIN
l

0

l

69
65

l

2.5

No Load

TYP

VS
73

Output Swing High (V+ – VOUT)

No Load

mV
mV

70

110
160

mV
mV

160

250
450

mV
mV

70

100
150

mV
mV

130

175
225

mV
mV

300

500
750

mV
mV

–80

–35
–30

mA
mA

l

ISOURCE = 5mA
l

ISOURCE = 25mA
l

ISC

Output Short-Circuit Current

Sourcing
l

Sinking
l

IS

Supply Current per Amplifier

60
40

VCM = Half Supply

100
1
1.4

mA
mA

1.25

1.4
1.8

mA
mA

42

75
200

µA
µA

l

ISD

Disable Supply Current per Amplifier

VSHDN = 0.8V
l

ISHDNL
ISHDNH

SHDN Pin Current Low
SHDN Pin Current High

VL

SHDN Pin Input Voltage Low

VSHDN = 0.8V

–3
–4

–1.6

l

0
0

µA
µA

–300
–350

35

l

300
350

nA
nA

0.8

V

VSHDN = 2V
l

VH

SHDN Pin Input Voltage High

IOSD

Output Leakage Current Magnitude in
Shutdown

VSHDN = 0.8V, Output Shorted to Either
Supply

tON

Turn-On Time

tOFF

Turn-Off Time

BW

–3dB Closed Loop Bandwidth

AV = 1, RL = 1k to Half Supply

GBW

Gain-Bandwidth Product

f = 2MHz, RL = 1k to Half Supply

mA
mA

0.95
l

VCM = V+ – 0.5V

V

40
55

l

VOH

V

25

l

ISINK = 25mA

UNITS
dB
dB

5.25

l

ISINK = 5mA

MAX

l

2

V
100

nA

VSHDN = 0.8V to 2V

5

µs

VSHDN = 2V to 0.8V

2

µs

l

100
70

120

MHz

180

MHz
MHz

tS , 0.1%

Settling Time to 0.1%

AV = –1, VO = 2V Step RL = 1k

74

ns

tS , 0.01%

Settling Time to 0.01%

AV = –1, VO = 2V Step RL = 1k

202

ns

SR

Slew Rate

AV = –3.33, 4.6V Step (Note 11)

90

V/µs
V/µs

4

MHz

l

FPBW

Full Power Bandwidth

VOUT = 4VP-P (Note 13)

60
50

624678fa



LTC6246/LTC6247/LTC6248
electrical characteristics

(VS = 5V) The l denotes the specifications which apply across the
specified temperature range, otherwise specifications are at TA = 25°C. For each amplifier VS = 5V, 0V; VSHDN = 2V; VCM = VOUT = 2.5V,
unless otherwise noted.
SYMBOL

PARAMETER

CONDITIONS

MIN

TYP

MAX

UNITS

HD2/HD3

Harmonic Distortion
RL = 1k to Half Supply

fC = 100kHz, VO = 2VP-P
fC = 1MHz, VO = 2VP-P
fC = 2MHz, VO = 2VP-P

110/90
88/80
78/62

RL = 100Ω to Half Supply

fC = 100kHz, VO = 2VP-P
fC = 1MHz, VO = 2VP-P
fC = 2MHz, VO = 2VP-P

90/79
66/60
59/51

ΔG

Differential Gain (Note 14)

AV = 1, RL = 1k, VS = ±2.5V

0.2

%

Δθ

Differential Phase (Note 14)

AV = 1, RL = 1k, VS = ±2.5V

0.08

Deg

Crosstalk

AV = –1, RL = 1k to Half Supply,
VOUT = 2VP-P, f = 1MHz

–90

dB

dBc
dBc
dBc

electrical characteristics

(VS = 2.7V) The l denotes the specifications which apply across the
specified temperature range, otherwise specifications are at TA = 25°C. For each amplifier VS = 2.7V, 0V; VSHDN = 2V; VCM = VOUT =
1.35V, unless otherwise noted.

SYMBOL

PARAMETER

CONDITIONS

VOS

Input Offset Voltage

VCM = Half Supply

MIN

TYP

MAX

UNITS

–100
–300

500

l

1000
1400

µV
µV

–1.75
–2.25

0.75

l

3.25
3.75

mV
mV

–700
–1000

–20

l

700
1000

µV
µV

–3.5
–4

0.1

l

3.5
4

mV
mV

VCM = V+ – 0.5V, NPN Mode
∆VOS

Input Offset Voltage Match
(Channel-to-Channel) (Note 8)

VCM = Half Supply
VCM = V+ – 0.5V, NPN Mode

VOS TC

Input Offset Voltage Drift

IB

Input Bias Current (Note 7)

VCM = Half Supply

Input Offset Current

–450
–600

–100

450
600

nA
nA

50
0

350

l

1000
1500

nA
nA

–250
–350

–10

l

250
350

nA
nA

–250
–350

–10

l

250
350

nA
nA

VCM = Half Supply
VCM = V+ – 0.5V, NPN Mode

en

µV/°C

l

VCM = V+ – 0.5V, NPN Mode
IOS

2

l

Input Noise Voltage Density

f = 100kHz

4.6

nV/√Hz

Input 1/f Noise Voltage

f = 0.1Hz to 10Hz

1.7

µVP-P

in

Input Noise Current Density

f = 100kHz

1.8

pA/√Hz

CIN

Input Capacitance

Differential Mode
Common Mode

2
0.8

pF
pF

RIN

Input Resistance

Differential Mode
Common Mode

32
12

kΩ
MΩ

AVOL

Large Signal Voltage Gain

RL = 1k to Half Supply
(Note 12)

15
7.5

25

l

V/mV
V/mV

RL = 100Ω to Half Supply
(Note 12)

2
1.3

7.5

l

V/mV
V/mV

624678fa



LTC6246/LTC6247/LTC6248
electrical characteristics

(VS = 2.7V) The l denotes the specifications which apply across the
specified temperature range, otherwise specifications are at TA = 25°C. For each amplifier VS = 2.7V, 0V; VSHDN = 2V; VCM = VOUT =
1.35V, unless otherwise noted.
SYMBOL

PARAMETER

CONDITIONS

CMRR

Common Mode Rejection Ratio

VCM = 0V to 1.2V

ICMR

Input Common Mode Range

PSRR

Power Supply Rejection Ratio

VS = 2.5V to 5.25V
VCM = 1V

Supply Voltage Range (Note 6)
VOL

Output Swing Low (VOUT – V–)

MIN

TYP

80
78

100

l
l

0

l

69
65

l

2.5

No Load

73

Output Swing High (V+ – VOUT)

No Load

mV
mV

80

125
160

mV
mV

110

175
225

mV
mV

60

85
100

mV
mV

135

190
225

mV
mV

180

275
400

mV
mV

–35

–20
–15

mA
mA

l

ISOURCE = 10mA
l

ISC

Short Circuit Current

Sourcing
l

Sinking
l

IS

Supply Current per Amplifier

25
20

VCM = Half Supply

50
1
1.3

mA
mA

1

1.3
1.7

mA
mA

22

50
90

µA
µA

l

ISD

Disable Supply Current per Amplifier

VSHDN = 0.8V
l

ISHDNL
ISHDNH

SHDN Pin Current Low
SHDN Pin Current High

VSHDN = 0.8V

mA
mA

0.89
l

VCM = V+ – 0.5V

V

40
55

l

ISOURCE = 5mA

dB
dB
5.25

l

VOH

V

20

l

ISINK = 10mA

UNITS
dB
dB

VS

l

ISINK = 5mA

MAX

–1
–1.5

–0.5

l

0
0

µA
µA

–300
–350

45

l

300
350

nA
nA

0.8

V

VSHDN = 2V

VL

SHDN Pin Input Voltage

l

VH

SHDN Pin Input Voltage

l

IOSD

Output Leakage Current Magnitude in Shutdown VSHDN = 0.8V, Output Shorted to Either
Supply

tON

Turn-On Time

tOFF

2.0

V
100

nA

VSHDN = 0.8V to 2V

5

µs

Turn-Off Time

VSHDN = 2V to 0.8V

2

µs

BW

–3dB Closed Loop Bandwidth

AV = 1, RL = 1k to Half Supply

GBW

Gain-Bandwidth Product

f = 2MHz, RL = 1k to Half Supply
l

80
50

100

MHz

150

MHz

tS , 0.1

Settling Time to 0.1%

AV = –1, VO = 2V Step RL = 1k

119

ns

tS , 0.01

Settling Time to 0.01%

AV = –1, VO = 2V Step RL = 1k

170

ns

SR

Slew Rate

AV = –1, 2V Step

55

V/µs

624678fa



LTC6246/LTC6247/LTC6248
electrical characteristics

(VS = 2.7V) The l denotes the specifications which apply across the
specified temperature range, otherwise specifications are at TA = 25°C. For each amplifier VS = 2.7V, 0V; VSHDN = 2V; VCM = VOUT =
1.35V, unless otherwise noted.
SYMBOL

PARAMETER

CONDITIONS

FPBW

Full Power Bandwidth

VOUT = 2VP-P (Note 13)

3.3

MHz

Crosstalk

AV = –1, RL = 1k to Half Supply,
VOUT = 2VP-P, f = 1MHz

–90

dB

Note 1: Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.
Note 2: The inputs are protected by back-to-back diodes. If any of
the input or shutdown pins goes 300mV beyond either supply or the
differential input voltage exceeds 1.4V the input current should be limited
to less than 10mA. This parameter is guaranteed to meet specified
performance through design and/or characterization. It is not production
tested.
Note 3: A heat sink may be required to keep the junction temperature
below the absolute maximum rating when the output current is high.
Note 4: The LTC6246C/LTC6247C/LTC6248C and LTC6246I/LTC6247I/
LTC6248I are guaranteed functional over the temperature range of –40°C
to 85°C. The LTC6246H/LTC6247H/LTC6248H are guaranteed functional
over the temperature range of –40°C to 125°C.
Note 5: The LTC6246C/LTC6247C/LTC6248C are guaranteed to meet
specified performance from 0°C to 70°C. The LTC6246C/LTC6247C/
LTC6248C are designed, characterized and expected to meet specified
performance from –40°C to 85°C but are not tested or QA sampled at
these temperatures. The LTC6246I/LTC6247I/LTC6248I are guaranteed
to meet specified performance from –40°C to 85°C. The LTC6246H/
LTC6247H/LTC6248H are guaranteed to meet specified performance from
–40°C to 125°C.

MIN

TYP

MAX

UNITS

Note 6: Minimum supply voltage is guaranteed by power supply rejection
ratio test.
Note 7: The input bias current is the average of the average of the currents
through the positive and negative input pins.
Note 8: Matching parameters are the difference between amplifiers A and
D and between B and C on the LTC6248; between the two amplifiers on the
LTC6247.
Note 9: Thermal resistance varies with the amount of PC board metal
connected to the package. The specified values are with short traces
connected to the leads with minimal metal area.
Note 10: The output voltage is varied from 0.5V to 4.5V during
measurement.
Note 11: Middle 80% of the output waveform is observed. RL = 1k at half
supply.
Note 12: The output voltage is varied from 0.5V to 2.2V during
measurement.
Note 13: FPBW is determined from distortion performance in a gain of +2
configuration with HD2, HD3 < –40dBc as the criteria for a valid output.
Note 14: Differential gain and phase are measured using a Tektronix
TSG120YC/NTSC signal generator and a Tektronix 1780R video
measurement set.

Typical Performance Characteristics
VOS Distribution, VCM = VS/2
(MS, PNP Stage)
22

25

VS = 5V, 0V
20 V = 2.5V
CM
18

16

VS = 5V, 0V
14 VCM = 4.5V

VS = 5V, 0V
VCM = 2.5V

14
12
10
8
6

PERCENT OF UNITS (%)

20

16

PERCENT OF UNITS (%)

PERCENT OF UNITS (%)

VOS Distribution, VCM = V+ – 0.5V
(MS, NPN Stage)

VOS Distribution, VCM = VS/2
(TSOT-23, PNP Stage)

15

10

5

4

10
8
6
4
2

2
0
–375

12

–250 –150 –50 50 150 250
INPUT OFFSET VOLTAGE (µV)

350

624678 G01

0
–175 –125 –75 –25 25
75 125
INPUT OFFSET VOLTAGE (µV)

175

624678 G02

0
–2000

–1200
–400
400
1200
INPUT OFFSET VOLTAGE (µV)

2000
624678 G03

624678fa



LTC6246/LTC6247/LTC6248
Typical Performance Characteristics
VOS Distribution, VCM = V+ – 0.5V
(TSOT-23, NPN Stage)

VOS vs Temperature
(MS10, PNP Stage)

18

500

VOLTAGE OFFSET (µV)

14

PERCENT OF UNITS (%)

2500

VS = 5V, 0V
400 VCM = 2.5V
6 DEVICES
300

12
10
8
6

VS = 5V, 0V
2000 VCM = 4.5V
6 DEVICES
1500
VOLTAGE OFFSET (µV)

VS = 5V, 0V
16 VCM = 4.5V

200
100
0
–100

500
0
–500

–1000

–200

–1500

2

–300

–2000

0
–2000

–400
–55 –35 –15

–1200
–400
400
1200
INPUT OFFSET VOLTAGE (µV)

2000

5 25 45 65 85 105 125
TEMPERATURE (°C)

600
400

2500

500

2000

400

1500

300

1000
500
0
–500

0
–55 –35 –15

5 25 45 65 85 105 125
TEMPERATURE (°C)

–200

–400
–500

–55°C
25°C

–1.0
–1.5
–2.0
–100 –75 –50 –25 0
25 50
OUTPUT CURRENT (mA)

75

100

624678 G10

0

0.5 1 1.5 2 2.5 3 3.5 4 4.5
INPUT COMMON MODE VOLTAGE (V)

Input Bias Current
vs Common Mode Voltage
800

VS = ±2.5V
0 TA = 25°C

VS = 5V, 0V

600

–10
–15
–20
–25

125°C
25°C

400

–5

200
0
–200

–55°C

–400
–600
–800

–1000
–1200

–30
–35

5

624678 G09

INPUT BIAS CURRENT (nA)

CHANGE IN OFFSET VOLTAGE (µV)

0.5

125°C

–300

5
125°C

25°C

–100

Warm-Up Drift vs Time

VS = ±2.5V

1.0

–55°C

0

624678 G08

Offset Voltage vs Output Current

–0.5

100

VS = 2.7V, 0V
–1500 VCM = 2.2V
6 DEVICES
–2000
–55 –35 –15 5 25 45 65 85 105 125
TEMPERATURE (°C)

624678 G07

1.5

VS = 5V, 0V

200

–1000

200

0

Offset Voltage
vs Input Common Mode Voltage

OFFSET VOLTAGE (µV)

VOLTAGE OFFSET (µV)

VS = 2.7V, 0V
VCM = 1.35V
1000 6 DEVICES
800

5 25 45 65 85 105 125
TEMPERATURE (°C)
624678 G06

VOS vs Temperature
(MS10, NPN Stage)

1200

2.0

–2500
–55 –35 –15

624678 G05

VOS vs Temperature
(MS10, PNP Stage)

VOLTAGE OFFSET (µV)

1000

4

624678 G04

VOS (mV)

VOS vs Temperature
(MS10, NPN Stage)

–1400
0

20

40 60 80 100 120 140 160
TIME AFTER POWER-UP (s)
624678 G11

–1600

0

0.5

1 1.5 2 2.5 3 3.5 4 4.5
COMMON MODE VOLTAGE (V)

5

624678 G12

624678fa



LTC6246/LTC6247/LTC6248
Typical Performance Characteristics
Input Bias Current vs Temperature

VCM = 4.5V

400
300
200
100
VCM = 2.5V

0
–100
–200
–55

–25

65
5
35
TEMPERATURE (°C)

95

1.0
0.5
0
0.5

0

1

3

2

624678 G13

1.25

SUPPLY CURRENT (mA)

SUPPLY CURRENT (mA)

4 5 6 7
TIME (1s/DIV)

0.60
TA = –55°C
0.40
TA = 25°C

0.20

in, VCM = 4.5V

9

8

0.1

10

10

1

25°C

SHUTDOWN CURRENT

–0.25

–55°C

0.75

0.50

0.25

1
3
2
4
TOTAL SUPPLY VOLTAGE (V)

0

5

–0.50
–0.75
–1.00

–55°C

–1.25
–1.50
–1.75

25°C

–2.00

0

0.5

624678 G16

12

125°C

1.5 2 2.5 3 3.5 4
SHDN PIN VOLTAGE (V)

4.5

5

Minimum Supply Voltage,
VCM = VS/2 (PNP Operation)

5

OFFSET VOLTAGE (mV)

–55°C

6
4

25°C

2

125°C

VCM = VCC – 0.5V

3
2
1

0

0

–2

–1

125°C

25°C
2

2.5

3.5
3
4
4.5
5
TOTAL SUPPLY VOLTAGE (V)

5.5

624678 G19

0

0.5

1.5 2 2.5 3 3.5 4
SHDN PIN VOLTAGE (V)

1

2

2.5

–55°C

3.5
3
4
4.5
5
TOTAL SUPPLY VOLTAGE (V)

5.5

624678 G20

4.5

5

624678 G18

Output Saturation Voltage
vs Load Current (Output High)

Minimum Supply Voltage,
VCM = V+ – 0.5V (NPN Operation)

4

8

–2.50

624678 G17

10
OFFSET VOLTAGE (mV)

1

10M

VS = 5V, 0V

0

125°C

10
OUTPUT HIGH SATURATION VOLTAGE (V)

0

1k 10k 100k 1M
FREQUENCY (Hz)

SHDN Pin Current
vs SHDN Pin Voltage

–2.25
0

100

624678 G15

0.25

VS = 5V, 0V

1.00

0.80

in, VCM = 2.5V

1.0

Supply Current Per Amplifier
vs SHDN Pin Voltage

1.20

TA = 125°C

en, VCM = 2.5V
10

624678 G14

Supply Current
vs Supply Voltage (Per Amplifier)
1.00

en, VCM = 4.5V

100

–1.0
–1.5

125

1000

VS = ±2.5V

VOLTAGE NOISE (nV/√Hz)
CURRENT NOISE (pA/√Hz)

500

VOLTAGE NOISE (500nV/DIV)

INPUT BIAS CURRENT (nA)

1.5

VS = 5V, 0V

600

SHDN PIN CURRENT (µA)

700

Input Noise Voltage and Noise
Current vs Frequency

0.1Hz to 10Hz Voltage Noise

VS = ±2.5V

1
TA = 25°C

TA = 125°C

0.1
TA = –55°C

0.01
0.01

0.1
1
10
LOAD CURRENT (mA)

100
624678 G21

624678fa



LTC6246/LTC6247/LTC6248
Typical Performance Characteristics
Output Saturation Voltage
vs Load Current (Output Low)
120

1
TA = 125°C
TA = 25°C

TA = –55°C
0.01
0.01

0.1
1
10
LOAD CURRENT (mA)

100

TA = –55°C

100

SINK

80
60
20
0
–20
–40

TA = 125°C

–60

SOURCE

–80

RL = 100 TO GROUND

–6

0

–12

0.1

1
10
FREQUENCY (MHz)

30
20
10

50

VS = ±1.35V

VS = ±2.5V

0

VS = ±1.35V
–50

0
–10
–20
100k

1M

10M
FREQUENCY (Hz)

–100
100M 300M
624678 G28

GAIN BANDWIDTH (MHz)

GAIN (dB)

GAIN

TA = 25°C
RL = 1k

100
PHASE (DEG)

40

1.5 2 2.5 3 3.5
OUTPUT VOLTAGE (V)

1

4

200
180

Gain vs Frequency (AV = 2)

VS = ±2.5V
TA = 25°C
RF = RG = 1k
RL = 1k
0.1

1
10
FREQUENCY (MHz)

100
624678 G27

Gain Bandwidth and Phase
Margin vs Temperature
70
60

PHASE MARGIN

50

GAIN BANDWIDTH PRODUCT

160
140
120
100
2.5

3

4
3.5
4.5
TOTAL SUPPLY VOLTAGE (V)

5

4.5

5
624678 G29

70

TA = 25°C
RL = 1k

60

PHASE MARGIN
300

VS = ±2.5V
50

VS = ±1.35V

40

250
200

PHASE MARGIN (DEG)

50

0.5

–18
0.01

100

PHASE MARGIN (DEG)

150

VS = ±2.5V

0

–6

–12

VS = ±2.5V
TA = 25°C
RL = 1k

Gain Bandwidth and Phase
Margin vs Supply Voltage

TA = 25°C
70 RL = 1k

RL = 100 TO GROUND

624678 G26

Open Loop Gain and Phase
vs Frequency

PHASE

12

6

–24
0.01

2.5 2.7

80

RL = 1k TO GROUND

624678 G24

Gain vs Frequency (AV = 1)

624678 G25

60

–500

0

–18

1
1.5
2
OUTPUT VOLTAGE (V)

–200

GAIN (dB)

TA = 25°C
VS = 2.7V, 0V

GAIN (dB)

INPUT VOLTAGE (µV)

6

RL = 1k TO GROUND

0.5

0
–100

624678 G23

RL = 1k TO MID SUPPLY

0

RL = 1k TO MID SUPPLY

100

–400

TA = 25°C
–100
1.25 1.45 1.65 1.85 2.05 2.25 2.45 2.65
POWER SUPPLY VOLTAGE (±V)

Open Loop Gain
RL = 100 TO MID SUPPLY

RL = 100 TO MID SUPPLY

200

–300

TA = –55°C

624678 G22

1000
900
800
700
600
500
400
300
200
100
0
–100
–200
–300

300

TA = 125°C

40

TA = 25°C
VS = 5V, 0V

400

TA = 25°C

GAIN BANDWIDTH (MHz)

0.1

Open Loop Gain
500

INPUT VOLTAGE (µV)

VS = ±2.5V

OUTPUT SHORT-CIRCUIT CURRENT (mA)

OUTPUT LOW SATURATION VOLTAGE (V)

10

Output Short-Circuit Current
vs Power Supply Voltage

GAIN BANDWIDTH PRODUCT
VS = ±2.5V

150
100
–55 –35 –15

VS = ±1.35V
5 25 45 65 85 105 125
TEMPERATURE (°C)
624678 G30

624678fa

10

LTC6246/LTC6247/LTC6248
Typical Performance Characteristics

10
1

AV = 2

AV = 1

0.1
0.01

0.001
100k

1M

10M
100M
FREQUENCY (Hz)

90
80
70
60
50
40
30
20
10
0
–10

1G

10

100

1k

RISING, VS = ±2.5V

80

FALLING, VS = ±1.35V

VS = ±2.5V
70 VOUT = 100mVP-P
AV = 1
VIN
60
RS = 10Ω

AV = 1

–
+

RS VOUT

5 25 45 65 85 105 125
TEMPERATURE (°C)

30

–40

–100
–110
–120
0.01

RL = 1kΩ, 3RD
RL = 1kΩ, 2ND
0.1
1
FREQUENCY (MHz)

10
624678 G37

DISTORTION (dBc)

DISTORTION (dBc)

–90

100

10k 100k 1M 10M 100M
FREQUENCY (Hz)

1k

500Ω
500Ω
VIN
RS = 10Ω

50

RS
AV = 2

VOUT
CL

RS = 20Ω

40
30

–
+

RS = 49.9Ω

VS = ±2.5V
= 200mVP-P
V
10 ROUT
F = RG = 500Ω,
AV = 2
0
100
1000
10
CAPACITIVE LOAD (pF)

RS = 49.9Ω
10

100
1000
CAPACITIVE LOAD (pF)

10000

Distortion vs Frequency
(AV = 1, 2.7V)

–70
–80
–90

–40

Distortion vs Frequency
(AV = 2, 5V)

VS = ±2.5V
–50 VOUT = 2VP-P
AV = 2

RL = 100Ω, 3RD

RL = 100Ω, 3RD

–60
RL = 100Ω, 2ND

RL = 1kΩ, 2ND

RL = 1kΩ, 3RD

–70

–90

–100

–110

–110
0.1
1
FREQUENCY (MHz)

10
624678 G38

RL = 100Ω, 2ND

–80

–100

–120
0.01

10000
624678 G36

–60

–80

10

20

VS = ±1.35V
–50 VOUT = 1VP-P
AV = 1

–70 RL = 100Ω, 2ND

0

60

CL

624678 G35

VS = ±2.5V
–50 VOUT = 2VP-P
AV = 1
RL = 100Ω, 3RD

10

70

RS = 20Ω

40

0

Distortion vs Frequency
(AV = 1, 5V)

–60

20

80

624678 G34

–40

30

Series Output Resistor
vs Capacitive Load (AV = 2)

50

10
40
–55 –35 –15

POSITIVE SUPPLY

40

Series Output Resistor
vs Capacitive Load (AV = 1)

20

RISING, VS = ±1.35V

60

NEGATIVE SUPPLY

50

624678 G33

OVERSHOOT (%)

FALLING, VS = ±2.5V
OVERSHOOT (%)

SLEW RATE (V/µs)

80

AV = –1, RL = 1k, VOUT = 4VP-P (±2.5V),
2VP-P (±1.35V) SLEW RATE MEASURED
AT MIDDLE 2/3 OF OUTPUT

100

60

624678 G31

Slew Rate vs Temperature

120

VS = ±2.5V
TA = 25°C

70

–10

10k 100k 1M 10M 100M 1G
FREQUENCY (Hz)

624678 G31

140

80
POWER SUPPLY REJECTION RATIO (dB)

AV = 10

TA = 25°C
VS = ±2.5V

100

DISTORTION (dBc)

100
OUTPUT IMPEDANCE (Ω)

110

VS = ±2.5V

COMMON MODE REJECTION RATIO (dB)

1000

Power Supply Rejection Ratio
vs Frequency

Common Mode Rejection Ratio
vs Frequency

Output Impedance vs Frequency

–120
0.01

RL = 1kΩ, 3RD

RL = 1kΩ, 2ND

0.1
1
FREQUENCY (MHz)

10
624678 G39

624678fa

11

LTC6246/LTC6247/LTC6248
Typical Performance Characteristics

DISTORTION (dBc)

–60 RL = 100Ω, 2ND
–70

RL = 1kΩ, 2ND

–80

RL = 1kΩ, 3RD

–90

–100
VS = ±1.35V
–110 VOUT = 1VP-P
AV = 2
–120
0.1
1
0.01
FREQUENCY (MHz)

10
624678 G40

VS = ±2.5V
180 AV = 1
T = 25°C
160 A

4

3

2

VS = ±2.5V
TA = 25°C
RL = 1kΩ
1 HD2, HD3 < –40dBc
AV = 2
AV = –1
0
0.1
1
0.01
FREQUENCY (MHz)

200

–
+

1k

160 VIN
140

VOUT

100

60
10mV

10mV

10

0

–4

–3

–2

–1
0
1
2
OUTPUT STEP (V)

3

4

624678 G42

Large Signal Response

0V

1V/DIV
VOUT
1.6V/DIV

20
–2

1mV

0V

10mV

–3

1mV

80

20

VSHDN
2.5V/DIV

10mV

–4

100

0V

60
40

120

40

1mV

1mV

80

140

SHDN Pin Response Time

1k

120

VOUT
1k

VS = ±2.5V
AV = –1
TA = 25°C

1k

180

VIN

–
+

624678 G41

Settling Time vs Output Step
(Inverting)

SETTLING TIME (ns)

200

5

SETTLING TIME (ns)

–50

0

Settling Time vs Output Step
(Noninverting)

RL = 100Ω, 3RD
OUTPUT VOLTAGE SWING (VP-P)

–40

Maximum Undistorted Output
Signal vs Frequency

Distortion vs Frequency
AV = 2, 2.7V)

–1
0
1
2
OUTPUT STEP (V)

3

4

AV = 1
VS = ±2.5V
RL = 1k
VIN = 1.6V

624678 G44

10µs/DIV

AV = 1
VS = ±2.5V
RL = 1k

200ns/DIV

624678 G45

624678 G43

Small Signal Response

Output Overdriven Recovery

0V
VIN
1V/DIV

0V
25mV/DIV

0V
VOUT
2V/DIV
AV = 1
VS = ±2.5V
RL = 1k

50ns/DIV

624678 G46

AV = ±2
VS = ±2.5V
RL = 1k
VIN = 3VP-P

100ns/DIV

624678 G47

624678fa

12

LTC6246/LTC6247/LTC6248
Pin Functions
–IN: Inverting Input of Amplifier. Valid input range from V–
to V+.

V– : Negative Supply Voltage. Typically 0V. This can be made
a negative voltage as long as 2.5V ≤ (V+ – V–) ≤ 5.25V.

+IN: Non-Inverting Input of Amplifier. Valid input range
from V– to V+.

SHDN: Active Low Shutdown. Threshold is typically 1.1V
referenced to V–. Floating this pin will turn the part on.

V+ : Positive Supply Voltage. Allowed applied voltage
ranges from 2.5V to 5.25V when V– = 0V.

OUT: Amplifier Output. Swings rail-to-rail and can typically
source/sink over 50mA of current at a total supply of 5V.

Applications Information
Circuit Description
The LTC6246/LTC6247/LTC6248 have an input and output
signal range that extends from the negative power supply
to the positive power supply. Figure 1 depicts a simplified
schematic of the amplifier. The input stage is comprised
of two differential amplifiers, a PNP stage, Q1/Q2, and an
NPN stage, Q3/Q4 that are active over different common
mode input voltages. The PNP stage is active between
the negative supply to nominally 1.2V below the positive
supply. As the input voltage approaches the positive supply, the transistor Q5 will steer the tail current, I1, to the
current mirror, Q6/Q7, activating the NPN differential pair

and the PNP pair becomes inactive for the remaining input
common mode range. Also, at the input stage, devices Q17
to Q19 act to cancel the bias current of the PNP input pair.
When Q1/Q2 are active, the current in Q16 is controlled to
be the same as the current in Q1 and Q2. Thus, the base
current of Q16 is nominally equal to the base current of
the input devices. The base current of Q16 is then mirrored
by devices Q17 to Q19 to cancel the base current of the
input devices Q1/Q2. A pair of complementary common
emitter stages, Q14/Q15, enable the output to swing from
rail-to-rail.

V+
V+

+

ESDD1

I2

R3

V–
ESDD2

+

I1

D6

D8

D5

D7

–IN

CC
Q4

Q3

Q1

Q16
Q17

Q18

Q19

Q7

ESDD5

V–
OUT

Q9

V+

I3

Q2
BUFFER
AND
OUTPUT BIAS

Q10
V–

C2

+

VBIAS

Q5

Q15

Q13

ESDD3

ESDD4

R5

Q12

Q11

+IN

R4

ESDD6

Q8
C1

Q6
R1

R2

V–

Q14

624678 F01

Figure 1. LTC6246/LTC6247/LTC6248 Simplified Schematic Diagram

624678fa

13

LTC6246/LTC6247/LTC6248
APPLICATIONS INFORMATION
Input Offset Voltage

Input Protection

The offset voltage will change depending upon which
input stage is active. The PNP input stage is active from
the negative supply rail to approximately 1.2V below the
positive supply rail, then the NPN input stage is activated
for the remaining input range up to the positive supply rail
with the PNP stage inactive. The offset voltage magnitude
for the PNP input stage is trimmed to less than 500µV with
5V total supply at room temperature, and is typically less
than 150μV. The offset voltage for the NPN input stage
is typically less than 1.7mV with 5V total supply at room
temperature.

The input stages are protected against a large differential
input voltage of 1.4V or higher by 2 pairs of back-to-back
diodes to prevent the emitter-base breakdown of the input
transistors. In addition, the input and shutdown pins have
reverse biased diodes connected to the supplies. The current in these diodes must be limited to less than 10mA.
The amplifiers should not be used as comparators or in
other open loop applications.

Input Bias Current
The LTC6246 family uses a bias current cancellation circuit to compensate for the base current of the PNP input
pair. When the input common mode voltage is less than
200mV, the bias cancellation circuit is no longer effective
and the input bias current magnitude can reach a value
above 1µA. For common mode voltages ranging from
0.2V above the negative supply to 1.2V below the positive
supply, the low input bias current of the LTC6246 family
allows the amplifiers to be used in applications with high
source resistances where errors due to voltage drops
must be minimized.
Output
The LTC6246 family has excellent output drive capability.
The amplifiers can typically deliver over 50mA of output
drive current at a total supply of 5V. The maximum output current is a function of the total supply voltage. As
the supply voltage to the amplifier decreases, the output
current capability also decreases. Attention must be paid
to keep the junction temperature of the IC below 150°C
(refer to the Power Dissipation Section) when the output
is in continuous short circuit. The output of the amplifier
has reverse-biased diodes connected to each supply. If
the output is forced beyond either supply, extremely high
current will flow through these diodes which can result
in damage to the device. Forcing the output to even 1V
beyond either supply could result in several hundred milliamps of current through either diode.

ESD
The LTC6246 family has reverse-biased ESD protection
diodes on all inputs and outputs as shown in Figure 1.
There is an additional clamp between the positive and negative supplies that further protects the device during ESD
strikes. Hot plugging of the device into a powered socket
must be avoided since this can trigger the clamp resulting
in larger currents flowing between the supply pins.
Capacitive Loads
The LTC6246/LTC6247/LTC6248 are optimized for high
bandwidth and low power applications. Consequently they
have not been designed to directly drive large capacitive
loads. Increased capacitance at the output creates an additional pole in the open loop frequency response, worsening the phase margin. When driving capacitive loads, a
resistor of 10Ω to 100Ω should be connected between the
amplifier output and the capacitive load to avoid ringing
or oscillation. The feedback should be taken directly from
the amplifier output. Higher voltage gain configurations
tend to have better capacitive drive capability than lower
gain configurations due to lower closed loop bandwidth
and hence higher phase margin. The graphs titled Series
Output Resistor vs Capacitive Load demonstrate the transient response of the amplifier when driving capacitive
loads with various series resistors.

624678fa

14

LTC6246/LTC6247/LTC6248
Applications Information
Feedback Components

Power Dissipation

When feedback resistors are used to set up gain, care
must be taken to ensure that the pole formed by the
feedback resistors and the parasitic capacitance at the
inverting input does not degrade stability. For example if
the amplifier is set up in a gain of +2 configuration with
gain and feedback resistors of 5k, a parasitic capacitance
of 5pF (device + PC board) at the amplifier’s inverting
input will cause the part to oscillate, due to a pole formed
at 12.7MHz. An additional capacitor of 5pF across the
feedback resistor as shown in Figure 2 will eliminate any
ringing or oscillation. In general, if the resistive feedback
network results in a pole whose frequency lies within the
closed loop bandwidth of the amplifier, a capacitor can be
added in parallel with the feedback resistor to introduce
a zero whose frequency is close to the frequency of the
pole, improving stability.

The LTC6246 and LTC6247 contain one and two amplifiers
respectively. Hence the maximum on-chip power dissipation for them will be less than the maximum on-chip
power dissipation for the LTC6248, which contains four
amplifiers.

5pF
5k

–
CPAR

VOUT

+

5k
VIN

624678 F02

Figure 2. 5pF Feedback Cancels Parasitic Pole

Shutdown
The LTC6246 and LTC6247MS have SHDN pins that can
shut down the amplifier to 42µA typical supply current.
The SHDN pin needs to be taken below 0.8V above the
negative supply for the amplifier to shut down. When left
floating, the SHDN pin is internally pulled up to the positive
supply and the amplifier remains on.

The LTC6248 is housed in a small 16-lead MS package and
typically has a thermal resistance (θJA) of 125°C/ W. It is
necessary to ensure that the die’s junction temperature
does not exceed 150°C. The junction temperature, TJ, is
calculated from the ambient temperature, TA, power dissipation, PD, and thermal resistance, θJA:
TJ = TA + (PD • θJA)
The power dissipation in the IC is a function of the supply
voltage, output voltage and load resistance. For a given
supply voltage with output connected to ground or supply,
the worst-case power dissipation PD(MAX) occurs when
the supply current is maximum and the output voltage at
half of either supply voltage for a given load resistance.
PD(MAX) is approximately (since IS actually changes with
output load current) given by:
2

V 
PD(MAX) = (VS •IS(MAX) ) +  S  / RL
 2
Example: For an LTC6248 in a 16-lead MS package operating
on ±2.5V supplies and driving a 100Ω load to ground, the
worst-case power dissipation is approximately given by
PD(MAX)/Amp = (5 • 1.3mA) + (1.25)2/100 = 22mW
If all four amplifiers are loaded simultaneously then the
total power dissipation is 88mW.
At the Absolute Maximum ambient operating temperature,
the junction temperature under these conditions will be:
TJ = TA + PD • 125°C/W
		 = 125 + (0.088W • 125°C/W) = 136°C
which is less than the absolute maximum junction temperature for the LTC6248 (150°C).
Refer to the Pin Configuration section for thermal resistances of various packages.
624678fa

15

LTC6246/LTC6247/LTC6248
Typical Applications
12-Bit ADC Driver
Figure 3 shows the LTC6246 driving an LTC2366 12-bit A/D
converter. The low wideband noise of the LTC6246 maintains a 70dB SNR even without the use of an intermediate
antialiasing RC filter. On a single 3.3V supply with a 2.5V
reference, a full –1dBFS output can be obtained without
the amplifier transitioning between input regions, thus
minimizing crossover distortion. Figure 4 shows an FFT
obtained with a sampling rate of 2.2Msps and a 350kHz
input waveform. Spurious free dynamic range is a quite
handsome 82dB.
3.3V 2.5V
3.3V

VDD VREF

+

VIN

AIN

LTC6246

–

499Ω
1%

499Ω
1%

CS
SDO

LTC2366
GND

SCK
OVDD
624678 F03

10pF

Low Noise Low Power DC-Accurate Single Supply
Photodiode Amplifier
Figure 5 shows the LTC6246 applied as a low power high
performance transimpedance amplifier for a photodiode.
A low noise JFET Q1 acts as a current buffer, with R2 and
R3 imposing a low frequency gain of approximately 1.
Transimpedance gain is set by feedback resistor R1 to
1MΩ. R4 and R5 set the LTC6246 inputs at 1V below
the 3V rail, with C3 reducing their noise contribution.
By feedback this 1V also appears across R2, setting the
JFET quiescent current at 1mA completely independent
of its pinchoff voltage and IDSS characteristics. It does
this by placing the JFETs 1mA VGS at the gate referenced
to the source, which is sitting 1V above ground. For this
JFET, that will typically be about 500mV, and this voltage
is imposed as a reverse voltage on the photodiode PD1.
At zero IPD photocurrent, the output sits at the same voltage and rises as photocurrent increases. As mentioned
before, R2 and R3 set the JFET gain to 1 at low frequency.
R1
1M, 1%

Figure 3. Single Supply 12-Bit ADC Driver

0

fIN = 350.195kHz
fSAMP = 2.2Msps
SFDR = 82dB
SNR = 70dB
1024 POINT FFT

–10
–20
MAGNITUDE (dB)

–30

C1
0.1pF

3V

IPD

Q1
NXP
BF862

PD1
OSRAM
SFH213

C2
6.8nF
FILM
OR NPO

–40
–50

R2
1k

3V

+

VOUT = VR + IPD • 1M

LTC6246

–
R3
1k

C3
0.1µF

–60
–70
–80

3V
R6
10M

–90
–100
–110

0

200

400
600
800
FREQUENCY (kHz)

R4
10k

+

Figure 4. 350kHz FFT Showing 82dB SFDR

3V

R7
1k

LT6003

1000
624678 F04

R5
20k

–

VR
C4
1µF

624678 F05

–3dB BW = 700kHz
ICC = 2.2mA
OUTPUT NOISE = 160µVRMS MEASURED ON A 1MHz BW
VOUT IS REFERRED TO VR
AT ZERO PHOTOCURRENT, VOUT = VR

Figure 5. Low Noise Low Power DC Accurate
Single Supply Photodiode Amplifier
624678fa

16

LTC6246/LTC6247/LTC6248
Typical Applications
60dB 5.5MHz Gain Block

This is not the lowest noise configuration for a transistor, as
downstream noise sources appear at the input completely
unattenuated. At low frequency, this is not a concern for a
transimpedance amplifier because the noise gain is 1 and
the output noise is dominated by the 130nV/√Hz of the 1MΩ
R1. However, at increasing frequencies the capacitance
of the photodiode comes into play and the circuit noise
gain rises as the 1MΩ feedback looks back into lower and
lower impedance. But capacitor C2 comes to the rescue.
In addition to the obvious quenching of noise source R3,
capacitor C2 increases the JFET gain to about 30 at high
frequency effectively attenuating the downstream noise
contributions of R2 and the op amp input noise. Thus the
circuit achieves low input voltage noise at high frequency
where it is most needed. Amplifier LT6003 is used to
buffer the output voltage of the photodiode and R7 and
C4 are used to filter out the voltage noise of the LT6003.
Bandwidth to 700kHz was achieved with this circuit, with
integrated output noise being 160µVRMS up to 1MHz. Total
supply current was a very low 2.2mA.

Figure 6 shows the LTC6247 configured as a low power
high gain high bandwidth block. Two amplifiers each
configured with a gain of 31V/V, are cascaded in series. A
660nF capacitor is used to limit the DC gain of the block
to around 30dB to minimize output offset voltage. Figure 7
shows the frequency response of the block. Mid-band
voltage gain is approximately 60dB with a –3dB frequency
of 5.5MHz, thus resulting in a gain-bandwidth product of
5.5GHz with only 1.9mA of quiescent supply current.
Single 2.7V Supply 4MHz 4th Order Butterworth Filter
Benefitting from low voltage operation and rail-to-rail
output, a low power filter that is suitable for antialiasing
can be built as shown in Figure 8. On a 2.7V supply the
filter has a passband of approximately 4MHz with 2VP-P
input signal and a stopband attenuation that is greater than
–75dB at 43MHz as shown in Figure 9. The resistor and
capacitor values can be scaled to reduce noise at the cost
of large signal power consumption and distortion.
65
60

1.5k

–

2.5V

1/2LTC6247

VIN

+

55
50

2.5V

1k

–

660nF

1/2LTC6247

+

–2.5V

–2.5V

GAIN (dB)

50Ω

30k

VOUT

45
40
35 VS = ±2.5V
VIN = 4.5mVP-P
30 RL = 1kΩ
DC GAIN = 30dB
25 (DUE TO 660nF DC BLOCKING CAP)
OUTPUT OFFSET = 4mV
20
10k
100k
1M
FREQUENCY (kHz)

624678 F06

Figure 6. 60dB 5.5MHz Gain Block

10M
624678 F07

Figure 7
10
910Ω

1.1k

0
–10

12pF
5.6pF
2.7k
56pF

–

1/2LTC6247

+

–20

2.7V
1.1k

2.3k
120pF

1.2V

–

2.7V

1/2LTC6247

VOUT

+

–30
–40
–50
–60
–70

624678 F08

Figure 8. Single 2.7V Supply 4MHz
4th Order Butterworth Filter

GAIN (dB)

VIN

910Ω

–80 VS = 2.7V, 0V
–90 VIN = 2VP-P
RL = 1kΩ to 0V
–100
10k
100k
1M
10M
FREQUENCY (kHz)

100M
624678 F09

Figure 9
624678fa

17

LTC6246/LTC6247/LTC6248
Package Description
KC Package
8-Lead Plastic UTDFN (2mm × 2mm)

(Reference LTC DWG # 05-08-1749 Rev Ø)
1.37 p0.05

R = 0.115
TYP 5
R = 0.05
TYP

2.00 p0.10
0.70 p0.05

2.55 p0.05
0.64 p0.05
1.15 p0.05

2.00 p0.10
PACKAGE
OUTLINE

1.37 p 0.10
8
0.40 p 0.10
PIN 1 NOTCH
R = 0.20 OR
0.25 s 45o
CHAMFER

0.64 p 0.10

PIN 1 BAR
TOP MARK
(SEE NOTE 6)

0.25 p 0.05
0.45 BSC
1.35 REF

(KC8) UTDFN 0107 REVØ

4
0.55 p0.05

0.125 REF

RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS
APPLY SOLDER MASK TO AREAS THAT ARE NOT SOLDERED

1

0.23 p 0.05
0.45 BSC
1.35 REF

BOTTOM VIEW—EXPOSED PAD

0.00 – 0.05

NOTE:
1. DRAWING IS NOT A JEDEC PACKAGE OUTLINE
2. DRAWING NOT TO SCALE
3. ALL DIMENSIONS ARE IN MILLIMETERS
4. DIMENSIONS OF EXPOSED PAD ON BOTTOM OF PACKAGE DO NOT INCLUDE
MOLD FLASH. MOLD FLASH, IF PRESENT, SHALL NOT EXCEED 0.15mm ON ANY SIDE
5. EXPOSED PAD SHALL BE SOLDER PLATED
6. SHADED AREA IS ONLY A REFERENCE FOR PIN 1 LOCATION ON THE
TOP AND BOTTOM OF PACKAGE

MS8 Package
8-Lead Plastic MSOP

(Reference LTC DWG # 05-08-1660 Rev F)
3.00 p 0.102
(.118 p .004)
(NOTE 3)

0.889 p 0.127
(.035 p .005)

5.23
(.206)
MIN

0.42 p 0.038
(.0165 p .0015)
TYP

3.20 – 3.45
(.126 – .136)

0.65
(.0256)
BSC

0.254
(.010)

8

7 6 5

3.00 p 0.102
(.118 p .004)
(NOTE 4)

4.90 p 0.152
(.193 p .006)

DETAIL “A”

0.52
(.0205)
REF

0o – 6o TYP

GAUGE PLANE

0.53 p 0.152
(.021 p .006)

RECOMMENDED SOLDER PAD LAYOUT

DETAIL “A”

1
1.10
(.043)
MAX

2 3

4
0.86
(.034)
REF

0.18
(.007)
SEATING
PLANE

0.22 – 0.38
(.009 – .015)
TYP

0.65
(.0256)
BSC

0.1016 p 0.0508
(.004 p .002)
MSOP (MS8) 0307 REV F

NOTE:
1. DIMENSIONS IN MILLIMETER/(INCH)
2. DRAWING NOT TO SCALE
3. DIMENSION DOES NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS.
MOLD FLASH, PROTRUSIONS OR GATE BURRS SHALL NOT EXCEED 0.152mm (.006") PER SIDE
4. DIMENSION DOES NOT INCLUDE INTERLEAD FLASH OR PROTRUSIONS.
INTERLEAD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.152mm (.006") PER SIDE
5. LEAD COPLANARITY (BOTTOM OF LEADS AFTER FORMING) SHALL BE 0.102mm (.004") MAX

624678fa

18

LTC6246/LTC6247/LTC6248
Package Description
MS Package
10-Lead Plastic MSOP

(Reference LTC DWG # 05-08-1661 Rev E)
0.889 ± 0.127
(.035 ± .005)

5.23
(.206)
MIN

3.20 – 3.45
(.126 – .136)
3.00 ± 0.102
(.118 ± .004)
(NOTE 3)

0.50
0.305 ± 0.038
(.0197)
(.0120 ± .0015)
BSC
TYP
RECOMMENDED SOLDER PAD LAYOUT

0.254
(.010)

10 9 8 7 6

3.00 ± 0.102
(.118 ± .004)
(NOTE 4)

4.90 ± 0.152
(.193 ± .006)

DETAIL “A”

0.497 ± 0.076
(.0196 ± .003)
REF

0° – 6° TYP

GAUGE PLANE

1 2 3 4 5
0.53 ± 0.152
(.021 ± .006)
DETAIL “A”

0.18
(.007)
SEATING
PLANE

0.86
(.034)
REF

1.10
(.043)
MAX

0.17 – 0.27
(.007 – .011)
TYP

0.50
(.0197)
BSC

NOTE:
1. DIMENSIONS IN MILLIMETER/(INCH)
2. DRAWING NOT TO SCALE
3. DIMENSION DOES NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS.
MOLD FLASH, PROTRUSIONS OR GATE BURRS SHALL NOT EXCEED 0.152mm (.006") PER SIDE
4. DIMENSION DOES NOT INCLUDE INTERLEAD FLASH OR PROTRUSIONS.
INTERLEAD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.152mm (.006") PER SIDE
5. LEAD COPLANARITY (BOTTOM OF LEADS AFTER FORMING) SHALL BE 0.102mm (.004") MAX

0.1016 ± 0.0508
(.004 ± .002)
MSOP (MS) 0307 REV E

624678fa

19

LTC6246/LTC6247/LTC6248
Package Description
MS Package
16-Lead Plastic MSOP

(Reference LTC DWG # 05-08-1669 Rev Ø)
0.889 p 0.127
(.035 p .005)

5.23
(.206)
MIN

3.20 – 3.45
(.126 – .136)

4.039 p 0.102
(.159 p .004)
(NOTE 3)

0.50
(.0197)
BSC

0.305 p 0.038
(.0120 p .0015)
TYP

RECOMMENDED SOLDER PAD LAYOUT

0.254
(.010)

DETAIL “A”

3.00 p 0.102
(.118 p .004)
(NOTE 4)

4.90 p 0.152
(.193 p .006)

0o – 6o TYP

0.280 p 0.076
(.011 p .003)
REF

16151413121110 9

GAUGE PLANE

0.53 p 0.152
(.021 p .006)
DETAIL “A”

0.18
(.007)
SEATING
PLANE

1.10
(.043)
MAX

0.17 – 0.27
(.007 – .011)
TYP

1234567 8

0.50
(.0197)
BSC

NOTE:
1. DIMENSIONS IN MILLIMETER/(INCH)
2. DRAWING NOT TO SCALE
3. DIMENSION DOES NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS.
MOLD FLASH, PROTRUSIONS OR GATE BURRS SHALL NOT EXCEED 0.152mm (.006") PER SIDE
4. DIMENSION DOES NOT INCLUDE INTERLEAD FLASH OR PROTRUSIONS.
INTERLEAD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.152mm (.006") PER SIDE
5. LEAD COPLANARITY (BOTTOM OF LEADS AFTER FORMING) SHALL BE 0.102mm (.004") MAX

0.86
(.034)
REF

0.1016 p 0.0508
(.004 p .002)
MSOP (MS16) 1107 REV Ø

624678fa

20

LTC6246/LTC6247/LTC6248
Package Description
S6 Package
6-Lead Plastic TSOT-23

(Reference LTC DWG # 05-08-1636)
0.62
MAX

2.90 BSC
(NOTE 4)

0.95
REF

1.22 REF

3.85 MAX 2.62 REF

1.4 MIN

2.80 BSC

1.50 – 1.75
(NOTE 4)
PIN ONE ID

RECOMMENDED SOLDER PAD LAYOUT
PER IPC CALCULATOR

0.30 – 0.45
6 PLCS (NOTE 3)

0.95 BSC
0.80 – 0.90

0.20 BSC

0.01 – 0.10

1.00 MAX

DATUM ‘A’

0.30 – 0.50 REF

0.09 – 0.20
(NOTE 3)

NOTE:
1. DIMENSIONS ARE IN MILLIMETERS
2. DRAWING NOT TO SCALE
3. DIMENSIONS ARE INCLUSIVE OF PLATING
4. DIMENSIONS ARE EXCLUSIVE OF MOLD FLASH AND METAL BURR
5. MOLD FLASH SHALL NOT EXCEED 0.254mm
6. JEDEC PACKAGE REFERENCE IS MO-193

1.90 BSC
S6 TSOT-23 0302 REV B

624678fa

21

LTC6246/LTC6247/LTC6248
Package Description
TS8 Package
8-Lead Plastic TSOT-23

(Reference LTC DWG # 05-08-1637)
0.52
MAX

2.90 BSC
(NOTE 4)

0.65
REF

1.22 REF

1.4 MIN

3.85 MAX 2.62 REF

2.80 BSC

1.50 – 1.75
(NOTE 4)
PIN ONE ID

RECOMMENDED SOLDER PAD LAYOUT
PER IPC CALCULATOR

0.22 – 0.36
8 PLCS (NOTE 3)

0.65 BSC
0.80 – 0.90

0.20 BSC

0.01 – 0.10

1.00 MAX

DATUM ‘A’

0.30 – 0.50 REF

0.09 – 0.20
(NOTE 3)

NOTE:
1. DIMENSIONS ARE IN MILLIMETERS
2. DRAWING NOT TO SCALE
3. DIMENSIONS ARE INCLUSIVE OF PLATING
4. DIMENSIONS ARE EXCLUSIVE OF MOLD FLASH AND METAL BURR
5. MOLD FLASH SHALL NOT EXCEED 0.254mm
6. JEDEC PACKAGE REFERENCE IS MO-193

1.95 BSC
TS8 TSOT-23 0802

624678fa

22

LTC6246/LTC6247/LTC6248
Revision History
REV

DATE

DESCRIPTION

PAGE NUMBER

A

2/10

Changes to Graph G15

9

624678fa

Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights.

23

LTC6246/LTC6247/LTC6248
Typical Application
700kHz, 1MΩ Single Supply Photodiode Amplifier

Output Noise Spectrum

R1
1M, 1%

R2
1k

PD1
OSRAM
SFH213

Q1
NXP
BF862
C2
6.8nF
FILM
OR NPO

3V

200
5V/DIV
LED DRIVER
VOLTAGE

C1
0.1pF

3V

IPD

Transient Response

R3
1k

R4
10k

20nV/√Hz/DIV

3V

+
–
C3
0.1µF

500mV/DIV
OUTPUT
WAVEFORM
0V

VOUT ≈ 0.5V + IPD • 1M

LTC6246

–3dB BW = 700kHz
ICC = 2.2mA
OUTPUT NOISE = 153µVRMS
MEASURED ON A 1MHz BW

0
10kHz

100kHz

500ns/DIV

1MHz

624678 TA02c

624678 TA02b

R5
20k
624678 TA02a

Related Parts
PART NUMBER DESCRIPTION

COMMENTS

Operational Amplifiers
LT1818/LT1819 Single/Dual Wide Bandwidth, High Slew Rate Low Noise and
Distortion Op Amps

400MHz, 9mA, 6nV/√Hz, 2500V/µs, 1.5mV –85dBc at 5MHz

LT1806/LT1807 Single/Dual Low Noise Rail-to-Rail Input and Output Op Amps 325MHz, 13mA, 3.5nV/√Hz, 140V/µs, 550µV, 85mA Output Drive
LT6230/LT6231/ Single/Dual/Quad Low Noise Rail-to-Rail Output Op Amps
LT6232

215MHz, 3.5mA, 1.1nV/√Hz, 70V/µs, 350µV

LT6200/LT6201 Single/Dual Ultralow Noise Rail-to-Rail Input/Output Op Amps 165MHz, 20mA, 0.95nV/√Hz, 44V/µs, 1mV
LT6202/LT6203/ Single/Dual/Quad Ultralow Noise Rail-to-Rail Op Amp
LT6204

100MHz, 3mA, 1.9nV/√Hz, 25V/µs, 0.5mV

LT1468

90MHz, 3.9mA, 5nV/√Hz, 22V/µs, 175µV,
–96.5dB THD at 10VP-P, 100kHz

16-Bit Accurate Precision High Speed Op Amp

LT1803/LT1804/ Single/Dual/Quad Low Power High Speed Rail-to-Rail Input
LT1805
and Output Op Amps

85MHz, 3mA, 21nV√Hz, 100V/µs, 2mV

LT1801/LT1802 Dual/Quad Low Power High Speed Rail-to-Rail Input and
Output Op Amps

80MHz, 2mA, 8.5nV√Hz, 25V/µs, 350µV

LT6552

Single Supply Rail-to-Rail Output Video Difference Amplifier

75MHz (–3dB), 13.5mA, 55.5nV/√Hz, 350V/µs, 20mV

LT1028

Ultralow Noise, Precision High Speed Op Amps

75MHz, 9.5mA, 0.85nV/√Hz, 11V/µs, 40µV

LT6233/LT6234/ Single/Dual/Quad Low Noise Rail-to-Rail Output Op Amps
LT6235

60MHz, 1.2mA, 1.2nV/√Hz, 15V/µs, 0.5mV

LT6220/LT6221/ Single/Dual/Quad Low Power High Speed Rail-to-Rail Input
LT6222
and Output Op Amps

60MHz, 1mA, 10nV/√Hz, 20V/µs, 350µV

LT6244

50MHz, 7.4mA, 8nV/√Hz, 35V/µs, 100µV, Input Bias Current = 1pA

Dual High Speed CMOS Op Amp

LT1632/LT1633 Dual/Quad Rail-to-Rail Input and Output Precision Op Amps

45MHz, 4.3mA, 12nV/√Hz, 45V/µs, 1.35mV

LT1630/LT1631 Dual/Quad Rail-to-Rail Input and Output Op Amps

30MHz, 3.5mA, 6nV/√Hz, 10V/µs, 525µV

LT1358/LT1359 Dual/Quad Low Power High Speed Op Amps

25MHz, 2.5mA, 8nV/√Hz, 600V/µs, 800µV, Drives All Capacitive Loads

ADC’s
LTC2366

3Msps, 12-Bit ADC Serial I/O

72dB SNR, 7.8mW No Data Latency TSOT-23 Package

LTC2365

1Msps, 12-Bit ADC Serial I/O

73dB SNR, 7.8mW No Data Latency TSOT-23 Package

LTC1417

Low Power 14-Bit 400ksps ADC Parallel I/O

Single 5V or ±5V Supplies, 0V to 4.096V or ±2.048V Input Range

LTC1274

Low Power 12-Bit 400ksps ADC Parallel I/O

10mW Single 5V or ±5V Supplies, 0V to 4.096V or ±2.048V Input Range
624678fa

24 Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507

●

www.linear.com

LT 0210 REV A • PRINTED IN USA

 LINEAR TECHNOLOGY CORPORATION 2009

www.s-manuals.com



---

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Format                          : application/pdf
Title                           : LTC6246, LTC6247, LTC6248 - Datasheet. www.s-manuals.com.
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Subject                         : LTC6246, LTC6247, LTC6248 - Datasheet. www.s-manuals.com.
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