STV9211 View Datasheet(PDF) - STMicroelectronics
Part Name
Description
MFG CO.
'STV9211' PDF : 37 Pages View PDF
STV9211
2 FUNCTIONAL DESCRIPTION
Functional description
2.1 RGB input, clamping function
The three RGB inputs have to be supplied with a video signal (maximum peak-to-peak value = 1V)
through coupling capacitors (100 nF typ.).
The RGB inputs include a clamping function using the input serial capacitor as “memory capacitor”.
To avoid the discharge of this capacitor during the line (due to leakage current), the input voltage is
referenced to the ground.
This clamping function is gated by the BPCP pulse (Black Porch Clamping Pulse) which is internally
generated (see Figure 4). The Register 8 allows to choose the way to generate this BPCP
(see Figure 3 and Figure 4).
- Synchronization:
- Polarity:
- Edge:
- Width:
- Direct BPCP:
HS or BLK signal (Register 8, bit0)
Positive or negative (Automatic detection) when synchronized by HS
Positive or negative ( programmed via Register 9, bit 0) when
synchronized by BLK - see Note 1
Trailing or Leading (Register 8, bit1)
From 0.33µs to 1.33µs (Register 8, bit2 and bit3)
If the application provides the BPCP, one can program the direct
connection between Pin 19 and the internal BPCP (Register 8, bit4)
Note 1: When BPCP is synchronized by BLK, the leading edge of the BLK must be selected to get a proper
synchronization.
Figure 3: BPCP selection of synchronization edge
Synchronization
source
Edge selection
BPCP generation
HS
(R8, bit 0=0)
Trailing
(R8, bit 1=0)
Leading
(R8, bit 1=1)
HS (Pin 19)
Internal BPCP
HS (Pin 19)
Internal BPCP
BLK
(R8, bit 0=1)
Leading
(R8, bit 1=0)
BLK (Pin 20)
Internal BPCP
HS
(R8, bit 4=1)
HS (Pin 19)
_
Internal BPCP =HS
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