Page 1
LOW VOLTAGE NBFM IF SYSTEM
.
OPERATION FROM 1.8V TO 9V
.
LOW DRAIN CURRENT (4mA, Vs=4V)
.
HIGH SENSITIVITY
(-3dBinput limitingat 3µV)
.
8µV INPUT FOR20dBS/N
.
LOW EXTERNALFAIR COUNT
DESCRIPTION
The TDA7361 is a low-power narrow band FM IF
demodulation system operable to less than 2 V
supplyvoltage.
Thedeviceincludes Oscillator, Mixer, Limiting Amplifier, Q uadrat ure Discriminator, Op. Amp.
Squelch,ScanControl andMute Switch.
The TDA7361 is designed for use in NBFM dual
conversion communication equipments using a
455 KHz ceramic filter like cordless telephones,
walkie-talkies, scan receivers, etc.
TDA7361
DIP16
ORDERING NUMBER :TDA7361
SO16
ORDERING NUMBER : TDA7361D
PIN CONNECTION
June1993
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Page 2
TDA7361
PinFUNCTION
No Name Function
1-2 XTAL OSCILLATOR Connections for the Colpitts XTAL Oscillator.
3 MIXER OUT The Mixer is double balanced toreduce spurious products. The output
4 SUPPLY VOLTAGE Must be well decoupled with a 100nF ceramiccapacitor.
5 IF LIMITER INPUT Input pin of thesix stages amplifier with about 50µV limiting sensitivity and
6-7 DECOUPLING Good quality 100nF ceramic capacitors and a suitable layou are important.
8 QUADRATURE COIL A quadrature detector is udedto demodulate the 455kHz FM signal. The Q of
9 AUDIO OUTPUT SIGNAL The audio output signal is bufferedby an internal emitter follower.
10 OPERATIONAL
AMPLIFIER INPUT
11 OPERATIONAL
AMPLIFIER OUTPUT
12 SQUELCH INPUT The squelch trigger circuit with a low bias on the input (Pin 12) will force Pin
13 SCAN CONTROL Pulling Pin 12 above mute threshold (0.65V) will force Pin 13 toan impedance
14 MUTE An hysteresis of about 50mV at Pin 12 will effectively prevent jitter.
15 GND Ground Connection
16 10.7MHz MIXER INPUT Input of the Wide-bandMixer. Normally used as 10MHz/455kHz converter, it
The XTAL may bereplaced by an inductor (see Figure 5)if the application
does not require high stability.
impedance is 1.8kW to match the input impedance of a 455kHz ceramic filter.
1.8kΩ input impedance. The if outputis connected to the external quadrature
coil (Pin 8) via an internal10pF capacitor.
the quad coil has direct effect on output level and distorsion (see Figure6).
For proper operation the voltage shouldbe 100mV
Because of the low DC bias, the swing on the operational amplifieroutput is
limited to 500mV
This can be increased by adding a resistor from theoperational amplifier input
to ground.
13 high ; and Pin14 low.
of about 60kΩ to ground and Pin 14 will be an open circuit.
can be also used with input frequencies up to 60MHz.
RMS
.
RMS
.
BLOCKDIAGRAM
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TDA7361
ABSOLUTE MAXIMUM RATINGS
Symbol Parameter Value Unit
V
S
V
V
8
V
14
T
oper
T
stg
THERMALDATA
Symbol Parameter SO16 DIP16 Unit
R
th j-amb
ELECTRICAL CHARACTERISTICS
=25oC, unless otherwise specified
T
amb
Symbol Parameter Test Conditions Min. Typ. Max. Unit
V
S
I
S
V
V
V
O
V
9
R
9
G
V
V
11
I
B
V
T
R
m
V
13
G
C
R
C
SupplyVoltage 9 V
RF Input Voltage (Pin 16) 1 V
I
Detector Input Voltage 1 V
Mute Function Voltage - 0.5 to +5 V
Operating Ambient Temperature 0 to 70
Storage Temperature - 65, + 150
Junction-ambient Thermal Resistance Max. 200 100
SupplyVoltage Range 1.8 4 9 V
SupplyCurrent Squelch OFF
Squelch ON
InputQuieting Voltage S/N = 20dB 8 µV
I
InputLimiting Voltage - 3dB limiting 3 µV
I
3.8
4.7
Recovered Audio Output VI= 10mV 150 mV
Detector Output Voltage 1.5 V
Detector Output Impedance 400 Ω
Dtectot Center Frequency Slope 150 mV/kHz
OperationalAmplifier Gain f = 10kHz, GV=V11/V
40 55 dB
10
OperationalAmplifier Output Voltage 1.5 V
OperationalAmplifier Input Bias Current Pin 10 20 nA
Trigger Hysteresis 50 mV
Mute Switching Impedance Low
High
50
10
Scan Voltage Pin 12 High (2V)
Pin 12 Low (0V) 3.003.4
Mixer Converter Gain 30 dB
InputResistance 3.3 kΩ
I
InputCapacitance 2.2 pF
I
0.5 V
o
C/W
mA
mA
MΩ
V
RMS
PP
o
C
o
C
RMS
DC
DC
Ω
DC
DC
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Page 4
TDA7361
Figure2 : Test Circuit
Figure3 : SupplyCurrent versusSupplyVoltage Figure4: FM IF Characteristics
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Page 5
TDA7361
Figure5 : Colpitts XTAL Oscillator
Figure 6 : Effect of QuadratureCoil ”Q” on Audio
Figure7 : ApplicationInformation (49MHzcordlessreceiver)
Level and Distortion
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Page 6
TDA7361
SO16PACKAGE MECHANICAL DATA
DIM.
MIN. TYP. MAX. MIN. TYP. MAX.
A 1.75 0.069
a1 0.1 0.25 0.004 0.009
a2 1.6 0.063
b 0.35 0.46 0.014 0.018
b1 0.19 0.25 0.007 0.010
C 0.5 0.020
c1 45 (typ.)
D 9.8 10 0.386 0.394
E 5.8 6.2 0.228 0.244
e 1.27 0.050
e3 8.89 0.350
F 3.8 4.0 0.150 0.157
L 0.4 1.27 0.016 0.050
M 0.62 0.024
S 8 (max.)
mm inch
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Page 7
DIP16PACKAGE MECHANICAL DATA
TDA7361
DIM.
MIN. TYP. MAX. MIN. TYP. MAX.
a1 0.51 0.020
B 0.77 1.65 0.030 0.065
b 0.5 0.020
b1 0.25 0.010
D 20 0.787
E 8.5 0.335
e 2.54 0.100
e3 17.78 0.700
F 7.1 0.280
I 5.1 0.201
L 3.3 0.130
Z 1.27 0.050
mm inch
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TDA7361
Information furnishedis believed to be accurate and reliable. However, SGS-THOMSON Microelectronics assumes no responsibility
for theconsequences of useof such information norfor any infringement ofpatents or other rights of third partieswhich may result
from its use. No license isgranted byimplication orotherwise underany patent orpatent rights of SGS-THOMSON Microelectronics.
Specifications mentioned in this publication are subject to change without notice. This publication supersedes and replaces all
information previouslysupplied. SGS-THOMSON Microelectronics products arenot authorized foruse ascritical components in life
support devices or systems withoutexpress written approvalof SGS-THOMSON Microelectronics.
1994 SGS-THOMSON Microelectronics - AllRights Reserved
Australia- Brazil - France - Germany - Hong Kong - Italy- Japan - Korea - Malaysia -Malta - Morocco - The Netherlands- Singa-
pore - Spain - Sweden - Switzerland - Taiwan - Thaliand -United Kingdom - U.S.A.
SGS-THOMSON Microelectronics GROUP OF COMPANIES
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