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| Document ID | 83558 |
| Application ID | +eGdjQhv04dWpSNSmrqTOw== |
| Document Description | Owners Manual |
| Short Term Confidential | No |
| Permanent Confidential | No |
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| Document Type | User Manual |
| Display Format | Adobe Acrobat PDF - pdf |
| Filesize | 89.27kB (1115841 bits) |
| Date Submitted | 2000-01-26 00:00:00 |
| Date Available | 2000-02-17 00:00:00 |
| Creation Date | 2000-01-21 14:23:10 |
| Producing Software | Acrobat 4.0 Scan Plug-in for Windows |
| Document Lastmod | 2000-01-26 10:42:18 |
| Document Title | Owners Manual |
| Document Creator | Acrobat 4.0 Scan Plug-in for Windows |
l HIGH-PERFORMANCE
PRE-CERHFIED
TECHNHLBEIES RF mnsczlvan
SC SERIES TRANSCEIVER MODULE DESIGN GUIDE
DRAFT FOR FCC SUBMISSION DO NOT DISTRIBUTE UNTIL
APPROVAL IS GRANTED AND DOCUMENT CONTROL HAS
RELEASED!
DESCRIPTION:
Tile TOXXX-SC-PO transceiver module is designed lo! the
cost-elleclive. bi-direclional uansler ol wireless inlormalion.
The transceiver is oomplelely sell-contained and requires no
external RF components. The P0 version 01 the SC has HO'
been previously qualified as a mdular product when used
wiln lhe appropriate proprietary antennas This greatly i
reduces the lime I0 market and 005! OI producl inlroduclion. .
The Transceiver uiillles an advanced synlhesixed superhel L450
archileciure and has dived inIeriace Ior analog or digital
inlormalion, fully qualified UART-compatible data output. 1,
RSSI, low pwwer consumption. wide operan‘onal voltage, on- 0425»
board TX/FIX swilch, SAW Ironirend liller‘ and many other 1'
uselul leaiures, Fast turnaround limes along wilh lhe "Teflon—fl
support lor data tales lo 33,6Kbps, make lhe transceiver
suitable lor a wide range at applications, m r
FEATURES 0.13'
Precision crystal-controlled synthesized architecture 0L. ow
Transparent serial input
UAW—compatible data output PAC KAG E
Built-in date squelchlng O U T LIN E
High data-rate: 33,600st —
Can transmit intercom—quality audio
Single antenna ready (No TX/RX switch required)
Output power and harmonics are compatible with FCC regulations
Differential L0 dramatically reduces unintended radiation
Output power can be programmed with an external resistor
Good sensitivity (-92dBm typical at 10-5 BER)
SAW filter on front-end for superior out-of-band rejection
Received signal strength indication
Fast start-up and turnaround time
Wide input voluge range (2t7 to 16 VDC)
Very low power consumption (as low as 12 mA)
Power—down mode , souA max (ch 6 sv)
APPLICATIONS
Small Ana Networks
Vlnroless Rsizazms Modems ORD ERING lN FORMATION
Tale-nary
Data Collection PART it DESCRIPTION
Home/Industrial Automation
Long-Range RFID
0 Robotics
Revised 1/01/00
utoooooooooooc-oo
Tc-xxx-sc SC Series Transceiver
xx><=433 92, 565. 91mm
to...-
Page i
PERFORMANCE DATA TC-XXX-SC
ABOUT THESE MEASUREMENTS
The periormance parameters listed below are based on module operation at 25°C
lrom a 5VDC supply unless othewvise noted.
{in m
mm l ,
Center Frequency Fc SEE ABLE 1
Fc Tolerance 50
Ou|pul Power Po 75 4
Oulpul Power Comrol Range 12
Harmonlc Emlsslons Ph A3
oompalrble wnn FCC pan is
Spurious Emlsstons
Frequency Deflation 90 100
Data Meduuuen Bandwidth 2
Audlu Modulallon Bandwldlh 2
Modulallcn Vol|age
Dlgllal 0
Analog o
’HEGINE«SEGM
L0 Frequency Flo SEE TABLE 1
Flo Tolerance .5o
Local Oscrllalor Feedlnru 750
Spunous Emlssions oompatlble Wllh FCC pan 15
Receive Sensinvlly 794 oz
no Modulatlon Sensrllvny 416
Dara Sheer Bandwldln .2
Audio Bandwidth 2
Audlo Level 2110
11331 DC Ouipul Range 5 to 2.5
FlSSI Galrl Grssl 25
RSSl Dynarml: Range 80
Inpul impedance
Input vswn
m V
Poweron to Valid Receive 10
Power-on (0 Valld Transmn ‘ i 3
Fix |0 Valld TX Swllchmg } i ll 2 5
Duo Valld RX Swllchmg i l l 3.5
Mmlmum Oil-“me |0
Operating Voltage vcc (pin to; 2 7
Currenl Consumption Icc
TX Mode
le Mode
Sleep Mode
‘Wflam
Operational Temp
Page 2
NOTES:
lmo a 50-ohm load
LVLADJ left open
Maxlmum power when LVLADJ open. mrnlmum power when LVLADJ grounded
Pln 9 1s modulaled min a av square wave
For 10'5 BER al 9,600 naud
The audio bandwldm ls delermmed by the needs 01 llre dala ulcer ln audlo awl-canons 11 is highly
recommended mal me use Illter the audlo usan a low pass ruler with a maxlmum eulon ol 9er
Minlmum input pow level to ensure lhal me ourpul will hold a DC level
rhese paramerers are only characterlzed and not lesled
9) Measured trom Vismg edge on /PDN
1m Measured lronr "sung edge ul earner modulallon on lransmll slde lo valld data on reeeue srde
11) VCC on pm 10 is 5V
Center Frequency
TX RX LO UNITS
12) AC Coupled
Not Released MHz
Not Released MHz
MHZ
TC—433-SC
TC-868-SC
TC—91 680
Table I
*CAUTION*
This product incorporates numerous static-sensitive components.
Always wear an ESD wrist swap and observe proper ESD handling
procedures when working with this device Failure to observe this
precaution may result in module damage or lailure.
TYPICAL PERFORMANCE GRAPHS
‘ vcorunmq
1 Vang;
en...‘ m
Figure I, TXEN lo FLL lock liming
Page a
PIN DESCRIPTION
GND
RX DATA
AUDIO
RSSI
PDN
N/C
RXEN
TXEN
TXDATA
VIN
GND
GND
GND
GND
GND
GND
PWRLEV
GND
ANT
GND
figure 5: sc Senes Pinon/s (Viewed looking down on top cover)
PINtt Pin Title Description
1,11 43 Module Grounds
15-20 Gm“ he to Common Ground Plane
2 RXDATA Recovered Data Output
3 AUDIO Recovered Analog Output
Received Signal
4 “SS' Strength Indicator
Logic Low Powers Down
5 PD“ The Transcewer
Not Implemented
6 WC Do Not Connect
Receiver Enable Pm
7 nxeu Active ngn
Pull Low When .n rx
Transmitter Enabte Pin
a 7ng Active High
Pull Low When in nx
Analog or Dtgltal Content
9 TXDATA to be Transmitted
10 VIN 2.7-iavoc supply
500 Antenna Port
I2 ANT max Switched lnslue Modute
14 wt Open for Maximum Power
Insert Resistor to Lower Over Izdb Flange
Page 4
Figure 6» SC Series Block Dragmm
DESCRIPTION
The TC-XXX-SC module is a single-channel, hall—duplex digital/analog
transceiver designed tor wireless applications requiring range pertormance ol
<500 leet outside and (200 teet inside.
No external components (excluding an antenna) are required. The module
incorporates on-board switch allowing the use at a single antenna. Linx otters a
wide selection at antennas designed lor use with the transceiver module.
The transmit section oi the transceiver is capabte of producing up to 1mW ol
output power while maintaining harmonics and spurious emissions within legal
limits. The transmitter directly modulates the carrier with the baseband signal
present at the TXDATA pin. It the signal is analog in nature, it will FM modulate
the carrier. II this signal is a square~wave, then the transmitter modulation
method becomes FSK with a peak deviation oi +/450kHz.
‘Note‘ The TC-XXX-SC is designed to provide only intercom-quality audio,
Excessive deviation will cause distortion in the reproduced audio on the receiver
end. Please read the section “USING THE TCaXXX~SC FOR AUDIO
APPLICATIONS“ tor more intormationt
The power amplifier can be adjusted with a 12dB adjustment range. To adjust the
power. simply add an external resistorlrom the LVLADJ pin to ground. The value
01 this resistor will determine the output power. This is very useful to optimize a
product during FCC testing.
The receive section at the transceiver is capable ot recovering a signal as low as
-92dBm (typical). The receiver operates in a single conversion superhet
configuration, with an IF or 10.7 MHz. A quadrature demodulator is used to
recover the baseband audio signal from the carrier. This audio signal is filtered
and presented to the data slicer to reconstruct the digital waveforms used to
modulate the transmitter.
The transceiver is hall-duplex. Therelore, It can only be operated in one mode at
a time: either transmit mode or receive mode. When transmitting. the receiver is
powered down. lewise, the transmitter is powered down in receive mode,
The transceiver has an on-board voltage regulator that regulates the internal
VCC to 3.0V. This allows a wide operating voltage range at 2.7V to 15V. At 2.7V,
the internal regulator acts as a saturated switch. directly passing voltage through
to the internal electronics. The IPDN pin can be used to put the transceiver into
a low-current sleep mode (<50uA).
Page 5
TRANSMITTER OPERATION
The transmitter is a wide-band FM transmitter capable of generating 1mW of
output power into a 50-ohm load.
The transmitter is comprised of a L0 and crystal—controlled frequency
synthesizer. The frequency synthesizer phase locks the L0 to a precision crystal
to achieve a high—Q, low phase-noise oscillator.
FM modulation is achieved by varying a reactance in series with the reference
crystal. By modulating the transmitter in this manner, a wide modulation band-
width is achieved. If the transmitter were modulated at the LO. the frequency
synthesizer would track out any modulation within the bandwidth of the loop filter
(this is a common limitation of most synthesized FM transmitters).
The transmitter is designed to give a peak deviation of +/-50kHz with a 3V square
wave input. For 5V systems, we recommend adding a 3.0K resistor in series with
the TXDATA pin.
The output amplifier can be externally adjusted to control the output power from
v12dBm to OdBm. The LVLADJ pin is used to control the amplifier. When the
LVLADJ pin is at 3V, power is at its max and the transmitter will draw 25mA
typically. When LVLADJ is at OV, power is at its minimum and the transmitter will
draw 12mA typically.
An internal 1K pull-up resistor is used to pull LVLADJ to about 2.7V when the
transceiver is in transmit mode. To adjust the transmit power, simply place a
resistor from the LVLADJ pin to ground to form a voltage divider. Linx
recommends placing pads for this resistor whether you intend to use it or not. It
will be useful it the power has to be reduced to comply with applicable
regulations.
There are two timing parameters that are important to consider when designing
with the transceiver: Start-Up time and HX-to- TX time. The value for each is listed
under “Performance Specifications" section of this document. Please make sure
that you have a current data sheet prior to designing with the Transceiver.
The start-up time is measured as the time from the IPDN pin going high to the
transmitter being ready to transmit data.
The RXAto-TX time is measured as the time from the TXEN pin going high to the
transmitter being ready to transmit data.
It is important to note that TXEN and RXEN should never be high at the same
time. This will invalidate the timing parameters and may cause illegal emissions
from the transceiver.
RECEIVER OPERATION
The receiver is configured as a single conversion superhet FM receiver with a
baseband bandwidth of 17kHz.
Low level RF signals are filtered at the front end by a SAW band-pass filter. This
lilter reduces the signal levels of interfering transmitters such as pager towers
and cell phones.
The filtered signal is amplified and downeconverted to the 10.7 MHz IF using a
Page 6
highly-integrated FtF IC.
The L0 used for the receiver mixer is the same one used for the transmitter. It is
a differential L0 with very low emissions to ensure compliance with FCC
regulations. It is phase-locked to a precision crystal reference by the frequency
synthesizer to form a high-Q, low phase-noise oscillator.
The 10.7 MHz IF is amplified. filtered, and finally demodulated to recover the
audio baseband signal transmitted by the transmitter.
The audio output is filtered using a 3rd order active low-pass filter. A proprietary
data slicer is used to recover the CMOS voltage levels from the audio signal.
When the transmitter is on but not being modulated, or when the received signal
strength is too low to ensure proper demodulation. the data output is squelched
to a continuous high state. This ensures compatibility with common serial
UAFlT's.
The data slicer is capable of recreating squared waveforms in the 400Hz to
17kHz band, giving a data-rate bandwidth of 4800 baud to 33.6kBaud.
There are two timing parameters that are important to consider when designing
with the transceiver: start—up time and TX-to-FtX time.
The start~up time is measured as the time from the IPDN pin going high to the
receiver's data output being valid. The typical value for this time is about tomsec.
The TX—to—RX time is measured as the time from the FtXEN pin going high to the
receiver's data output being valid.The typical value for this time is about 7mSec.
It is important to note that TXEN and HXEN should never be high at the same
time. This will invalidate the timing parameters and may cause illegal emissions
from the transceiver.
POWER CONSIDERATIONS
POWER SUPPLY
The user must provide a clean source of power
to the receiver to ensure proper operation. In an
FM receiver, power-supply noise will manifest
itself as AM and FM noise in the receiver
circuitry, reducing the overall sensitivity of the
receiver. Providing a good power supply for the
module is a designer‘s first line of defense in the
battle for receiver sensitivity.
The TCAXXX-SC incorporates a precision Low- F’g"
Dropout Regulator on-board which allows the module to operate over an input
voltage range of 2.7 to 16 volts DC. The modules power-supply line should have
low ESR bypass capacitors configured as shown in figure 7.
re 7: Suggested supply filler
Page 7
BOARD LAYOUT CONSIDERATIONS
If you are at all familiar with RF devices. you may be concerned about
specialized layout requirements. Fortunately. because of the care taken by
Linx in the layout of the modules PCB, integrating an TC-XXX-SC receiver into
your design is very straightforward. By adhering carefully to a few basic
design and layout rules. you can enjoy a troublevfree path to RF success.
Figure 8 shows the suggested PCB footprint for the SC Series transceiver.
A ground—plane (as large as possible) should be placed directly under the SC
Transceiver. This ground—plane can also be critical to the performance of your
antenna.
The so should. as much as reasonably possible. be isolated from all other
components on your PCB. Specifically. high-frequency circuitry such as crystal
oscillators should be kept as far away as possible from the module.
The trace from the receiver to the antenna should be kept as short as possible.
A simple trace is suitable for runs up to 1/8 inch for antennas with wide bandwidth
characteristics. For longer runs or to avoid detuning a high-Q narrow bandwidth
antenna such as a helical. use a 50-ohm coax or 50-ohm microstrip transmission
line as described in the following section.
7.
Ground—plane on Lower Layer
0. 1 on" Tyn
a c
o o i
o o
o o
o o
o o
o o
o a
o o
o o\
50 mil pad WM 030" hole
Figure 8; Recommended PCB layout
MICROSTRIP DETAILS
A transmission line is a medium whereby RF energy is transferred from one
place to another with minimal loss. This is a critical factor. particularly in high
frequency products like the SC because the trace leading to the modules
antenna can effectively contribute to the length of the antenna. changing its
resonant bandwidth. In order to minimize loss and detuning. some form of
transmission line between the antenna and the module is needed. unless the
antenna connection can be made in close proximity:
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