June 1994

18

Philips Semiconductors

Product specification

Video analog input interface

TDA8708A

Fig.15 Example of an economical low-pass filter for CVBS and Y signals.

This filter can be adapted to various applications with respect to performance requirements. An input and output impedance of at least 680

Ω and 2.2 kΩ

must in any event be applied.

handbook, full pagewidth

MSA678

15 pF

15 pF

2.2 k

Ω

82

µH

ADOUT

(pin 19)

ADCIN

(pin 20)

VCCA

(pin 22)

680

Ω

Vo

V i

Fig.16 Frequency response for filter shown in Fig.15.

handbook, halfpage

010

30

0

10

30

40

20

MSA681

20

f (MHz)

α

(dB)

Characteristics of Fig. 15

• Order 5; adapted CHEBYSHEV

• Ripple ρ≤ 0.4 dB

• f = 6.5 MHz at −3 dB.