September 1999
PRELIMINARY
ML6411
Programmable Video Digitizer
with Selectable Gain and Clamps
FEATURES
GENERAL DESCRIPTION
The ML6411 is a Dual Video A/D converter, incorporating
two input sample and holds, two high speed 8-Bit A/D
converters, programmable gain control, selectable clamps,
multi-phase clocking, and reference voltage generation.
The ML6411 can be used to convert the following analog
signals to digital signals: two composite channels or S-
video channel.
■ Complete video digitizer for Y/C and CV video
■ Contains A/D’s with scalable gain, selectable clamps,
and clock generation (programmable via serial bus)
■ Two 8-Bit +/- ½ LSB Differential Non-Linearity with
30MHz guaranteed conversion
All inputs are provided with appropriate input selectable
clamps to establish DC level. The clamps are full DC
restore circuits with the A-to-D converters in each
respective correction loop. The clamps are selectable to
16, 24, 64, and 128. The programmable gain control
provides various possibilities to select and adjust the gain
via two separate mechanisms: Sync-Suppressed Gain
Control (SGC) for sync suppressed video such as RGB, and
User Gain Control (UGC) for video formats that require
scalable gain settings. Each of these can be programmed
through a serial bus.
■ Two Gain Control Mechanisms for programmable
or sync-suppressed video gain control
■ Selectable Video Clamping: 16, 24, 64, 128
■ Selectable Video Gain: 3dB to –6dB
■ Operating total power dissipation less than 425mW
■ Power down mode and Tri-state output control
■ Applications: Video Capture, Video Editing, Video
Cameras, Y/C and CV analog to digital conversion
■ 44-pin TQFP
BLOCK DIAGRAM
35
38
41
17
15
2
33
32
18
23
11
39
VINN
CLAMP
GATE
DGND
DVCC
RESET
AVCC1
AVCC2
AVCC3
DVCC
VCCO
OEA
OEB
REF1
44
36
42
CHANNEL A
S/H
SGC
SYNC SUPPRESS
GAIN CONTROL
UGC
USER GAIN
CONTROL
A
<7:0>
OUT
Y/CV1
C/CV2
Y OR CV1
CHANNEL A
LATCH
Y/CV1
GAIN PRESET
GAIN PRESET
ADC
24:31
CHANNEL B
S/H
SGC
SYNC SUPPRESS
GAIN CONTROL
UGC
USER GAIN
CONTROL
B
<7:0>
OUT
C OR CV2
CHANNEL B
LATCH
C/CV2
ADC
3:10
CLPA<1:0>
CLPB<1:0>
CLAMP
LEVEL
SERIAL BUS
SELECT
TIMING
GENERATOR
CLK
14
1
PD
19
SCLK
20
SDAT
21
22
REF
12
37
AGNDI
40
AGND2
43
AGND3
13
GNDO
16
DGND
34
NC
V
REF
CC
IN
OUT
1