Rainbow Electronics MAX7452 - Manual (Page 8)

MAX7450/MAX7451/MAX7452
Video-Signal Conditioners with AGC and
Back-Porch Clamp
8 _______________________________________________________________________________________
for the analog-to-digital conversion. This voltage must
be scaled by a ratio of two resistors to set the black
level of the video signal to the appropriate level (to
match the input range of the converter).
If the ADC or video decoder has a built-in clamp circuit,
the output of the MAX7452 must be AC-coupled into
the ADC with the capacitor value recommended for the
converter. In this situation, set the BPLVL on the
MAX7452 to the midpoint of the specified range for
optimum performance. In addition, the stability of this
voltage is not critical, provided that it stays within the
specified range.
Power-Supply Bypassing and Layout
Bypass all supply pins to GND with 0.1µF and 1µF
capacitors. These capacitors filter higher frequencies in
the MHz range. Place all external components as close to
the devices as possible. Connect EP to V
SS
for the
MAX7450/MAX7451. Connect EP to GND for the
MAX7452. Placing the IC onto a copper area the size of
the pad is recommended for proper power dissipation.
Refer to the MAX7450 Evaluation Kit for a proven PC-
board layout example.
Chip Information
TRANSISTOR COUNT: 6316
PROCESS: BiCMOS
MAX7452
NOISE
FILTER
V CC
V
SS
LOS
SYNC SEPARATOR
AND AMPLITUDE
DETECTOR
AGCD
IN OUT VIDEO
INPUT
BPLVL
±6dB 0 OR +6dB
GAIN SET (0dB OR +6dB)
ADC
DSP
REF
VIDEO DECODER
Figure 3. MAX7452 Interfaced to a Video Decoder
OUT
AGCD V
SS
(MAX7450/MAX7451)
BPLVL (MAX7452)
1
2
8
7
LOS
GSET IN
GND
V CC
SO-EP*
TOP VIEW
*CONNECT EP TO V SS FOR THE MAX7450/MAX7451
3
4
6
5
MAX7450
MAX7451
MAX7452
Pin Configuration