Philips TDA1596T User Manual

INTEGRATED CIRCUITS

DATA SH EET

TDA1596T

IF amplifier/demodulator for FM
radio receivers

Product specification
File under Integrated Circuits, IC01

April 1991

Philips Semiconductors Product specification

IF amplifier/demodulator for FM radio

TDA1596T

receivers

GENERAL DESCRIPTION

The TDA1596T provides IF amplification, symmetrical quadrature demodulation and level detection for quality home and
car FM radio receivers and is suitable for both mono and stereo reception. It may also be applied to common front-ends,
stereo decoders and AM receiver circuits.

Features

• Simulates behaviour of a ratio detector (internal field strength and detuning-dependent voltage for dynamic AF signal
muting)

• Mono/stereo blend and field strength indication control voltage

• Three-state mode switch for FM, mute-on / FM, mute-off / FM-off

• Internal compensation of AF signal total harmonic distortion (THD)

• Two open collector stop pulse outputs for microcomputer tuning control (can be one stop pulse output by

wired-ANDing)

• Internal reference voltage source

• Built-in hum and ripple rejection circuits.

QUICK REFERENCE DATA

SYMBOL PARAMETER CONDITIONS MIN. TYP. MAX. UNIT

V

P

I

P

V

4(rms)

S/N Signal-to-noise ratio V

Supply voltage (pin 1) 7.5 8.5 12.0 V
Supply current (pin 1) VP= 8.5 V; I2= I7= 0 mA − 20 26 mA
AF output voltage (RMS value) V

= 10 mV 180 200 220 mV

20(rms)

= 10 mV; fm= 400 Hz;

20(rms)

− 82 − dB

∆f = 75 kHz

THD Total harmonic distortion V

= 10 mV; fm= 1 kHz;

20(rms)

− 0.1 0.3 %
I7= 0 mA; ∆f = 75 kHz; FM mute
on; without de-emphasis;
without detuning

T

amb

Operating ambient temperature

−40 −+85 °C

range

SEE ALSO DATA SHEET FOR TDA1596

PACKAGE OUTLINE

20-lead mini-pack; plastic (SO20; SOT163A); SOT163-1; 1996 August 12.

April 1991 2

Philips Semiconductors Product specification

IF amplifier/demodulator for FM radio
receivers

TDA1596T

April 1991 3

Fig.1 Block diagram and application circuit.

minimum 2nd harmonic distortion at pin 4.

(1) Connecting pin 13 to ground is only allowed for measuring the current at pin 16. It is not for use in application.

(2) In the FM, mute-on condition the unweighted level detector output is available from pin 3. In the FM, mute-off condition the variable resistor at pin 3 can be adjusted for

Philips Semiconductors Product specification

IF amplifier/demodulator for FM radio
receivers

PINNING

1V
2 LVA level voltage adjustment
3 ULV unweighted level output/K2 adjustment
4 AF0 AF output
5V
6 WLV weighted level voltage output
7 MSW mode switch
8 DDV detune detector voltage
9 n.c. not connected
10 DMI1 demodulator input 1
11 DMI2 demodulator input 2
12 n.c. not connected
13 TSW tau switch
14 ST1 stop pulse output 1
15 ST0 stop pulse output 0
16 MTV mute voltage
17 GND ground
18 LFD1 IF limiter feedback 1
19 LFD2 IF limiter feedback 2
20 IFI IF input

P

ref

supply voltage

reference voltage output

TDA1596T

Fig.2 Pinning diagram.

April 1991 4

Philips Semiconductors Product specification

IF amplifier/demodulator for FM radio

TDA1596T

receivers

FUNCTIONAL DESCRIPTION
Limiter-amplifier

This has five stages of IF amplification using balanced differential limiter-amplifiers with emitter--follower coupling.
Decoupling of the stages from the voltage supply lines and an internal high-ohmic DC feed-back loop give a very stable
IF performance. The amplifier gain is virtually independent from temperature changes.

FM demodulator

The demodulator is fully balanced and comprises two cross-coupled differential amplifiers. Quadrature detection of the
FM signal is performed by feeding one differential amplifier directly from the limiter--amplifier output, and the other via an
external 90° phase-shifting network. The demodulator has good stability and its zero cross-over shift is small. The
bandwidth of the demodulator output is restricted to approximately 1 MHz by an internal low-pass filter.

THD compensation

This circuit compensates non-linearities introduced by demodulation. For this to operate correctly the demodulator circuit
between pins 10 and 11 must have a loaded Q-factor of 19. Consequently there is no need for the demodulator tuned
circuit to be adjusted for minimum THD, instead the adjustment criterium is for a symmetrical stop pulse.

Mute attenuator and AF output

The control voltage for the mute attenuator at pin 16 is generated from the values of the level detector and the detuning
detector outputs. The mute attenuator has a fast attack and a slow decay which is determined by the capacitor at pin 16.
The AF signal is passed via the mute attenuator to the output at pin 4.

A weighted control voltage, available from pin 6, is obtained from the mute attenuator control voltage via a buffer-amplifier
which introduces an additional voltage shift and gain.

Level detector

The level detector generates a voltage output which is proportional to the field strength of the input signal. The
unweighted level detector output is available when the mode switch is operating in the FM, mute-on condition.

Tuning-stop outputs

The open collector outputs STOP-0 and STOP-1 (from pins 15 and 14 respectively) are voltages derived from the
detuning level and the field strength of the input signal. If only one tuning-stop output is required, pins 14 and 15 may be
tied together.

April 1991 5

Philips Semiconductors Product specification

IF amplifier/demodulator for FM radio

TDA1596T

receivers

RATINGS

Limiting values in accordance with the Absolute Maximum System (IEC 134)

SYMBOL PARAMETER MIN. MAX. UNIT

= V

V

P

1-17

V

5-17

V

2-17

V

7-17

V

13-17

V

3-17

V

15-17

V

14-17

I

15

I

14

T

stg

T

amb

V

es

V

es

V

es

Supply voltage (pin 1) −0.3 +16 V
Reference voltage range (pin 5) −0.3 + 10 V
Level adjustment range (pin 2) −0.3 + 10 V
Mode switch voltage range (pin 7) −0.3 V

P

Control input voltage range (pin 13) −+6V
THD compensation/unweighted field

strength voltage range (pin 3) −0.3 V

P

Tuning-stop output voltage range

STOP-0 (pin 15) −0.3 V
STOP-1 (pin 14) −0.3 V

P
P

Tuning-stop output current

STOP-0 (pin 15) − 2mA

STOP-1 (pin 14) − 2mA
Storage temperature range −55 + 150 °C
Operating ambient temperature range −40 + 85 °C
Electrostatic handling

(1)

all pins except pins 5 and 6 −2000 + 2000 V

pin 5 −2000 + 900 V

pin 6 −2000 + 1600 V

V

V

V
V

Note

1. Equivalent to discharging a 100 pF capacitor through a 1.5 kΩ series resistor.

THERMAL RESISTANCE

From junction to ambient (in free air) R

th j-a (max.)

= 95 K/W

April 1991 6

Philips Semiconductors Product specification

IF amplifier/demodulator for FM radio

TDA1596T

receivers

CHARACTERISTICS

f = 10.7 MHz; V

P

= V

10, 11 aligned for symmetrical stop pulses; all voltages are referred to ground (pin 17), unless otherwise specified

SYMBOL PARAMETER MIN. TYP. MAX. UNIT

Supplies

= V

V

P

1

I

1

Supply voltage 7.5 8.5 12.0 V
Supply current at I2= I7= 0 mA − 20 26 mA

FM demodulator

R
C
V

10-11
10-11

4

Input impedance 25 40 55 kΩ

DC output voltage (no-signal condition) at
V

R

4-17

Output impedance − 400 −Ω

Mute attenuator control voltage

Control voltage (pin 16)

V

16

V

16

R
V

10-17

2

Output impedance (pin 16) −−2.0 MΩ
Level shift input (pin 2) internal bias voltage at

I2= 0 mA

R

2-17

Internal muting (Fig.6)

Internal attenuation of signals
± 22.5 kHz ≤ detuning ≤ ±80 kHz;

A = 20log[∆V4(FM mute-off)/∆V4(FM)]
A at V
A at V
A at V

= 8.5 V; VI = V

1-17

20 (rms)

= 1 mV; T

= 25 °C; measured in the circuit of Fig.3; tuned circuit at pins

amb

− 6 − pF

2.75 3.10 3.45 V

10, 11(p-p)

at V

20(rms)

at V

20(rms)

≤ 100 µV; V

≤ 5 µV − 2.0 − V

= 1 mV − 3.45 − V

20(rms)

≤ 5 µV

− 1.4 − V

input impedance 15 −−kΩ

≥ 1 V

16

= 0.77 V

16

= 0.55 V

16

5

5
5

− 0 − dB

1.5 3.0 4.5 dB

− 20 − dB

April 1991 7