13/14

Notes on video line driving

TA0310

Because of this, in series we place a resistance, Rs, which is used as isolation in order to limit the effect

of the capacitor on the op-amp stability.

The following graphs in Figures 18 and 19 give the frequency response of the TSH7x-8x and TSH11x

family when loaded by a chip-set input. 30pF is the worst case; a typical value is 10pF).

Figure 17: Typical load

Figure 18: TSH7x-8x behavior on capa-load

+

_

1k

Ω

TSH

30pF

Analog-to-Digital

Converter input

75

Ω

Video Line

TV or Set-top-box input

Set-top-box

DVD

Video Camera

1M

10M

100M

0

1

2

3

4

5

6

7

8

TSH7x-8x, Gain = +2

Capa Load = 30pF

R Load = 1kohms

Vcc = -5V/+5V

Rs = 82ohms

Vcc = 0/+5V

Rs = 91ohms

Frequency (Hz)