STV9555 ST Microelectronics, STV9555 Datasheet - Page 12

• Manufacturer Part Number: STV9555
• Description: 9.5 ns TRIPLE-CHANNEL HIGH VOLTAGE VIDEO AMPLIFIER
• Manufacturer: ST Microelectronics

STV9555
10
10.1 How to choose the high supply voltage value (V
The V
video adjustment but set to minimum value to avoid unecessary power dissipation.
Example (see
The following example shows how the optimum V
Case 1:
10V Brightness (C) adjusted by the preamplifier :
Case 2:
10V Brightness (C) adjusted by the G1 anode:
10.2 Arcing Protection: schematics
As the amplifier outputs are connected to the CRT cathodes, special attention must be given to protect
them against possible arcing inside the CRT.
Protection must be considered when starting the design of the video CRT board. It should always be
implemented before starting to adjust the dynamic video response of the system.
The arcing network that we recommend (see
the amplifier video performances.
The total resistance between the amplifier and the CRT cathode (R10+R11) protects the device against
overvoltages. We recommend to use R10+R11 > 200
Spark gaps are strongly recommended for arcing protection.
12/24
– Cut-off adjustment range (B) : 25V
– Max contrast (D) : 40V
V
V
V
V
DD
DD
DD
DD
DD
APPLICATION HINTS
= A + B + C + D + E
= 15V + 25V + 10V + 40V + 17V = 107V
= A + B + D + E
= 15V + 25V + 40V + 17V = 97V
high supply voltage must be chosen carefully. It must be high enough to provide the necessary
Figure
2):
Figure
DD
16) provides efficient protection without deteriorating
voltage value is determined:
.
DD
) in DC coupling mode