November 1987

5

Philips Semiconductors

Product specification

Television IF amplifier and demodulator

TDA8340

TDA8341

AGC control circuit

This converts the AGC detector voltage (pin 14) into a current signal which controls the gain of the IF amplifier. It also

provides a tuner AGC control output from pin 4, current limiting is incorporated to prevent internal damage. The AGC

starting point is adjusted via pin 3.

AFC circuit

The AFC circuit provides a voltage output which controls the IF frequency of the tuner. Video information on the AFC

output (pin 5) is eliminated by a sample-and-hold circuit (external capacitor at pin 6). Coupling between the AFC and

reference tuned circuits is via two small capacitors (or parasitic capacitance) between the respective tracks of the printed

circuit board. If the capacitance is less than 1 pF, the steepness of the AFC characteristic is reduced.

RATINGS

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

PARAMETER

SYMBOL

MIN.

MAX.

UNIT

Supply voltage (pin 11)

9,4

13,2

V

IF AGC voltage/VCR switch

−

13,2

V

Tuner AGC voltage

−

12

V

AFC switch voltage

−

13,2

V

Maximum voltage level with

VCR switch active

−

5,0

V

DC current at video output

−

10

mA

DC current at AFC output

−

10

mA

Total power dissipation

−

1,2

W

Storage temperature range

−55

+150

°C

Operating ambient temperature

−25

+70

°C