STV9553 Datasheet, PDF (17/24 Pages) STMicroelectronics – 12 ns TRIPLE-CHANNEL HIGH VOLTAGE VIDEO AMPLIFIER

STV9553
10.9 Stand-by mode, spot suppression
The usual way to set a monitor in stand-by mode is to switch-off the Vcc (12V).
The STV9553 has an extremely low power consumption (I_DDS = 60µA when V_CC<1.5V) in stand-by mode
and the outputs are set to low level (white picture).
To avoid the display of a spot effect during the switch-off phase, it is necessary to adjust the G1 circuitry
(Resistors Rx and Cx, see Figure 19) to pull the G1 voltage to low value during a sufficient time duration.
Figure 19. Stand-by mode, spot effect
+80V
Cathode
0V
-30V
G1
-120V
EHT
(27kV)
Case #1: Low Rx.Cx
A spot might appear during
the switch-off phase
Case #2: High Rx.Cx
No spot effect
Typical G1 generator circuitry
R1
G1
Cx
Rx
-120V
-30V
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