Philips TDA1574T User Manual

INTEGRATED CIRCUITS

DATA SH EET

TDA1574T

Integrated FM tuner for radio
receivers

Product specification
File under Integrated Circuits, IC01

August 1990

Philips Semiconductors Product specification

Integrated FM tuner for radio receivers TDA1574T

GENERAL DESCRIPTION

The TDA1574T is an integrated FM tuner circuit designed for use in the RF/IF section of car radios and home receivers.
The circuit contains a mixer and an oscillator and a linear IF amplifier for signal processing. The circuit also incorporates
the following features.

Features

• Keyed Automatic Gain Control (AGC)

• Regulated reference voltage

• Buffered oscillator output

• Electronic standby switch

• Internal buffered mixer driving.

QUICK REFERENCE DATA

PARAMETER CONDITIONS SYMBOL MIN. TYP. MAX. UNIT

Supply voltage range

(pin 17) V

P

Mixer input bias voltage

(pins 1 and 2) V

1,2-4

Noise factor NF − 9 − dB
Oscillator output voltage

(pin 6) V

6-4

Output admittance at pin 6 f = 108.7 MHz Y22 − 1.5 + j2 ms
Oscillator output buffer

DC output voltage (pin 9) V

9-4

Total harmonic distortion THD −−15 − dB
Linear IF amplifier output

voltage (pin 12) V

Noise factor R

= 300 Ω NF − 6.5 − dB

S

12-4

Keyed AGC output voltage

range (pin 20) V

20-4

7 − 14 V

− 1 − V

− 2 − V

− 6 − V

− 4.5 − V

0.5 − VP−0.3 V

PACKAGE OUTLINE

20-lead mini-pack; plastic (SO20; SOT163A); SOT163-1; 1996 September 9.

August 1990 2

Philips Semiconductors Product specification

Integrated FM tuner for radio receivers TDA1574T

Coil data

L1: TOKO MC-108, 514HNE-150023S14; L = 0.078 µH
L2: TOKO MC-111, E516HNS-200057; L = 0.08 µH
L3: TOKO Coil set 7P, N1 = 5.5 5.5 turns, N2 = 4 turns

Fig.1 Block diagram and test circuit.

August 1990 3

Philips Semiconductors Product specification

Integrated FM tuner for radio receivers TDA1574T

PINNING

1. Mixer input 1

2. Mixer input 2

3. Wideband information input

4. Ground

5. Voltage reference

6. Oscillator output

7. Oscillator input 1

8. Oscillator input 2

9. Buffered oscillator output

10. Not connected

11. Not connected

12. IF output

13. Standby switch

14. Narrowband information input

15. IF input 1

16. IF input 2

17. Supply voltage

18. Mixer output 1

19. Mixer output 2

20. AGC output

Fig.2 Pinning diagram.

FUNCTIONAL DESCRIPTION
Mixer

The mixer circuit uses a double balanced multiplier with a preamplifier (common base input) in order to obtain a large
signal handling range and low oscillator radiation.

Oscillator

The oscillator circuit uses an amplifier with a differential input. Voltage regulation is achieved by utilizing the symmetrical
tan h-transfer-function to obtain low order 2nd harmonics.

Linear IF amplifier

The IF amplifier is a one stage, differential input, wideband amplifier with an output buffer.

Keyed AGC

The AGC processor combines narrow and wideband information via an RF level detector, a comparator and an ANDing
stage. The level dependent current sinking output has an active load which sets the AGC threshold.
The AGC function can either be controlled by a combination of wideband narrowband information (keyed AGC) or by a
wideband/narrowband information only. If narrowband AGC is required pin 3 should be connected to pin 5. If wideband
AGC is required pin 14 should be connected to pin 15.

August 1990 4