tda8757a NXP Semiconductors, tda8757a Datasheet - Page 12

• Manufacturer Part Number: tda8757a
• Description: Tda8757a Triple 8-bit Adc 205 Msps
• Manufacturer: NXP Semiconductors

Philips Semiconductors
9397 750 09549
Preliminary data
Fig 6. Clamp definition.
programming
clamp
8.2 Clamps
CLP
If this function is not used, pin IN
supply. In this event pin SOG
Three independent parallel clamping circuits are used to clamp the video input
signals on several black levels. The clamping levels may be set from
They are controlled by changing the values in three 8-bit registers: OFFSETR,
OFFSETG and OFFSETB (see
offset from 100 mV to 10 mV within 300 ns, and correct the total offset in 10 lines.
The clamping is done using the following principle: On the incoming of a TTL positive
going pulse supplied on pin CLP, three external capacitors are loaded independently
by the device in order to change the voltage level of each analog RGB input. The
capacitors are connected to pins CLP
63.5 to +64 LSBs (RGB) and from +120 to +136 LSBs in steps of
Fig 5. Sync level diagram.
= 63.5
= 128
Clamp
Clamp
Clamp
Clamp
= 64
= 0
300 mV
600 mV
150 mV
300 mV
to
to
Rev. 01 — 22 March 2002
video signal
O
is at LOW-level TTL.
Table
SOG
blank level
blank level
should be connected to the analog power
150 mV comparison level
set by I
R
5). Each clamp must be able to correct an
80 mV comparison level
set by I
, CLP
2
C-bus bit Slevel = 0
2
C-bus bit Slevel = 1
G
and CLP
005aaa009
© Koninklijke Philips Electronics N.V. 2002. All rights reserved.
ADC
B
.
Triple 8-bit ADC 205 Msps
255
constant level
0
constant level
TDA8757A
FCE698
1
2
LSB (YUV).
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