STV9553

16/24

10.8

AC - Coupling mode

The STV9553 can be used in AC-Coupling mode in kit with the TDA9207/9212 preamplifier from ST. As

for the DC-coupling mode, the STV9553 drives perfectly the video signal in PICTURE BOOST conditions.

A typical schematic is given on the Figure 18 below.

Figure 18. Video response optimization for one channel - AC coupling application

consumption. This is due to the fact that the STV9553 provides only the video signal and not the cut-off

adjustment. The disadvantage is to have an application with more components (DC restore circuitry).

Note that it is mandatory to keep the output video signal (point C) inside the linear area of the amplifier

C24

4.7

µF

C11

4.7

µF

R10

L1

R11

CRT

OUT

STV9553

IN

150

Ω

150

Ω

0.33

µH

C10(*)

100nF

C12(*)

100nF

-

+

DC Restore

circuitry

Cut-off

C1

1

µF

OUT

R19(***)

33-40

Ω

Caution: For Application with Tr/Tf> 5.5ns, the PreAmplifier bandwidth register (BW, Register 13)

must be set to minimum value (0 dec)

(***): R19 must be mandatorily used

(****): Input Networks #2 and #3 can be used as well

C

GNDP

GNDS

GNDA

R1(**)

51

Ω

C1

1.5nF

Reference

C2

10pF

Input Network #1 (****)