SGS Thomson Microelectronics TDA1220B Datasheet
The TDA1220B is a monolithic integrat ed cir cuit i n
a 16-lead dual in-line package.
It is intended for quality receivers produced in large
quantities.
The functions incorporated are:
AM SECTION
– Preamplifier and double balanced mixer
– One pin local oscillat or
– IF amplifier with interna l AGC
– Detector and audio preamplifier
FM SECTION
– IF amplifier and lim iter
– Quadrature detector
– Audio preamplifier
The TDA1220B is suitable up to 30MHz AM and for
FM bands (including 450KHz narrow band) and
features:
– V ery cons tant charact eris tics (3V to 16V)
– High sensitivity and low noise
– V ery low tweet
TDA1220B
AM-FM QUALITY RADIO
DIP-16 Plastic
(0.25)
ORDERING NUMBER : TDA 1220BK
– Sensitivity regulation facility (*)
– High recovered audio signal suited for stereo
decoders and radio recorders
– V ery simple DC s witching of AM -FM
– Low current drain
– AFC facility
(*) Maximum AM sensitivit y can be reduced by means of a resistor
(5 to 12KΩ) between pin 4 and ground.
BLOCK DIAGRAM
March 1993
1/18
TDA1220B
ABSOLUTE MAXIMUM RATINGS
Symbol Parameter Value Unit
V
s
P
tot
T
op
T
, T
stg
PIN CONNECTION
(Top view)
Supply voltage 16 V
Total power dissipation at T
< 110°C
amb
400 mW
Operating temperature -20 to 85
Storage and junction temperature -55 to 150
j
°C
°C
THERMAL DATA
Symbol Parameter Value Unit
R
2/18
th-j-amb
Thermal resistance junction-ambient max 100
°C/W
TDA1220B
ELECTRICAL CHA RACTERIS TICS ( T
= 25 °C, Vs = 9V unless otherwis e specified, refer to test circuit)
amb
Symbol Parameter Test conditions Min. Typ. Max. Unit
V
Supply voltage 3 16 V
s
Id Drain current FM 10 15 mA
AM 14 20 mA
AM SECTION (f
V
i
= 1 MHz; fm = KHz)
o
Input sensitivity S/N = 26 dB m = 0.3 12 25
S/N Vi = 10 mV m = 0.3 45 52 dB
V
AGC range
i
V
Recovered audio signal
o
= 10 dB
∆V
out
Vi = 1 mV m = 0.3 80 130 200 mV
m = 0.8 94 100 dB
(pin 9)
d Distortion
= 1 mV
V
i
m = 0.3 0.4 1 %
m = 0.8 1.2 %
V
Max input signal handling
H
m = 0.8 d < 10% 1 V
capability
Input resistance between
R
i
m = 0 7.5
pins 2 and 4
Input capacitance between
C
i
m = 0 18 pF
pins 2 and 4
µV
KΩ
R
Output resistance (pin 9) 4.5 7 9.5
o
Tweet 2 IF
m = 0.3 Vi = 1 mV
40 dB
Tweet 3 IF 55 dB
FM SECTION (f
V
i
AMR Amplitude modulation
S/N Ultimate quieting
d Distortion
d Distortion
= 10.8 MHz; fm = 1 KHz)
o
Input limiting voltage -3 dB limiting point 22 36
rejection
∆f = ±22.5 KHz
= 3 mV
V
i
∆f = ±22.5 KHz
∆f = ±75 KHz
∆f = ±22.5 KHz
m = 0.3 40 50 dB
Vi = 1 mV 55 65 dB
= 1 mV 0.7 1.5 %
V
i
V
= 1 mV
i
0.25 0.5 %
d Distortion (double tuned) 0.1 %
V
Recovered audio signal
o
∆f = ±22.5 KHz
Vi = 1 mV 80 110 140 mV
(pin 9)
R
Input resistance between
i
6.5
pin 16 and ground
Ci Input capacitance between
14 pF
pin 16 and ground
R
Output resistance (pin 9) 4.5 7 9.5
o
KΩ
µV
KΩ
KΩ
3/18
TDA1220B
Figure 1. Test circuit
Figure 2. PC board and component layout (1:1 scale) of the test circuit
4/18
TDA1220B
Figure 3. Audio output, noise
and tweet levels vs. input
signal (AM section)
Figure 6. Audio output and
noise level vs. inpu t signal (FM
section)
Figure 4. Distortion vs. input
signal and modulation index
(AM section)
Figure 7. Distortion vs. input
signal (FM section)
Figure 5. Audio output vs.
supply voltag e (AM sectio n )
Figure 8. Audio output vs.
supply voltag e (F M sectio n )
Figure 9. Amplitude modulation rej ection vs. input signal
(FM section)
Figure 10. ∆ DC output voltage
(pin. 9) vs. frequ ency sh ift (FM
section)
Figure 11. ∆ DC outp ut vo l tag e
(pin 9) vs. ambient
temperature (FM section)
5/18
TDA1220B
APPLICATION INFORMATION
AM Section
RF Amplifier and mixer stages
The RF amplifier stage (pin 2) is connected directly to the secondary winding of the ferrite rod antenna or
input tuned circuit. Bias is provided at pin 4 which must be adequately decoupled. The RF amplif ier provides
stable performance ex tending beyond 30 MHz.
The Mixer employed is a double - balanced multiplier and the IF output at pin 3 is connected directly to the
IF filter coil.
Local oscillator
The local oscillator is a cross coupled differential s tage wh ich oscillates at the frequency determined by th e
load on pin 1.
The oscillator resonant circuit is trans former coupled t o pin 1 to improve the Q factor and frequency stability .
The oscillator level at pin 1 is about 100 mV rms and the performance extends beyond 30 MHz, however
to enhance the stability and reduce to a minimum pulling effects of the AGC operation or supply voltage
variations, a high C/L ratio should be used above 10 MHz.
An external oscillator can be injected at pin 1. The level should be 50 mV rms and pin 1 should be connected
to the supply via a 100W resistor .
IF Amplifier Detector
The IF amplifier is a wide band amplifier with a tuned output stage.
The IF filters can be either LC or mixed LC/ceramic.
AM detectio n occurs at pin 7. A detection capacitor is connected t o pin 6 to reduc e the ra diation of spurious
detector products.
The Audio output is at pin 9 (for either AM or FM); the IF frequency is filtered by an external capacitor which
is also used as the FM mono de-enphasis network. The audio output impedance is about 7KΩ and a high
impedance load (~ 50K Ω ) must be used.
AGC
Automatic gain control operates in two ways.
With weak signals it acts on the IF gain, maintaining the maximum S/N. For strong signals a second circuit
intervenes which controls the entire chain and allows signal handling in excess of one volt (m = 0.8).
At pin 8 there is a carrier envelope signal whic h is filtered by an external c apacitor to rem ove the Audio and
RF content and obtain a mean DC signal to drive the AGC circuit.
6/18
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