VPC 323xD, VPC 324xD
ADVANCE INFORMATION
5.1. Application Note: VGA mode with VPC 3215C
In 100 Hz TV applications it can be desirable to display
a VGA-signal on the TV. In this case a VGA-graphic
card delivers the H, V and RGB signals. These signals
can be feed "directly" to the backend signal process-
ing. The VPC can generate a stable line locked clock
for the 100 Hz system in relation to the VGA sync sig-
nals.
While the V-sync is connected to the VGAV pin directly,
the H-sync has to be pulse-shaped and amplitude
adjusted until it is connected to one of the video input
pins of the VPC. The recommended circuitry to filter
the H sync is given in the figure below.
+5V analog
100 Ω
47pF
680 nF
1kΩ
Video Input VPC
270 Ω
540 Ω
H 31kHz
BC848B
1N4148
2kΩ
1N4148
GND analog
GND analog
Fig. 5–1: Application circuit for horizontal VGA-input
72
Micronas
MICRONAS [ MICRONAS ]
