1996 Nov 20

8

Philips Semiconductors

Product specification

Dual channel TV FM intercarrier

sound demodulator

TDA9821

Notes

1. The output signal at pin 7 can only be measured when mute is disabled. This is achieved by inserting a resistor of

2.7 k

Ω between pin 15 and ground. In this event the input impedance is 490 Ω.

2. Improvement of ripple rejection is possible by connecting series RC between pin 11 and pin 14 (15 k

Ω + 2.2 µF;

see Fig.5) for a supply voltage of 4.5 to 5.5 V. The rejection of ripple frequencies up to 3 kHz is improved, but up to

200 kHz is worse; see Fig.3.

Fig.3 Typical improvement.

The curves are typical and valid for ripple frequencies between 50 Hz and 3 kHz.

ripple rejection measurement: unweighted RMS.

(1) Without RC.

(2) With R = 15 k

Ω and C = 2.2 µF.

handbook, full pagewidth

9

VP (V)

40

30

10

0

4

5678

RR

(dB)

20

MHA530

(2)

(1)