Rainbow Electronics MAX9595 - Manual (Page 11)

MAX9595
Audio/Video Switch for Dual SCART Connector
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Fast switching consists of two inputs from the encoder
and VCR, and one output to the TV to insert an on-
screen display (OSD). Fast switching is used to route
video signals from the VCR or from the encoder to the
TV. In addition, the fast-switching output can be config-
ured to a high or low voltage. Fast switching is con-
trolled through the I
2 C interface.
The digital block contains the 2-wire interface circuitry,
control, and status registers. The MAX9595 can be
configured through an I
2 C-compatible interface.
DEV_ADDR sets the I 2 C-compatible address.
SCART Video Switching
The MAX9595 switches video signals between an MPEG
decoder, TV SCART, and VCR SCART. The video switch
includes reconstruction filters, multiplexed video ampli-
fiers, and a Y-C mixer driver for an RF modulator. See
Figure 1 for the functional diagram of the video section.
While the SCART connector supports RGB, S-video, and
composite video formats, RGB, and S-video typically
share a bidirectional set of SCART connector pins.
CLAMP/BIAS TV_R/C_IN
CLAMP TV_Y/CVBS_IN
CLAMP VCR_B_IN
CLAMP VCR_G_IN
CLAMP/BIAS VCR_R/C_IN
VCRIN_FS
CLAMP ENC_Y/CVBS_IN
CLAMP/BIAS ENC_R/C_IN
CLAMP ENC_G_IN
CLAMP ENC_B_IN
CLAMP ENC_Y_IN
ENCIN_FS
BIAS ENC_C_IN
0.7V
0.7V
2kΩ
2kΩ
V 12
VCR_Y/CVBS_OUT
VCR_R/C_OUT
TV_R/C_OUT
TV_G_OUT
TV_B_OUT
TV_Y/CVBS_OUT
TVOUT_FS
RF_CVBS_OUT
INTERRUPT_OUT
BIAS
5V
0V
PULLDOWN
TVRCOUT
VGA
5dB, 6dB, OR 7dB
PULLDOWN
VCRRCOUT
x2
x2
x2
x1
TV_SS
VCR_SS
x2
VGA
5dB, 6dB, OR 7dB
VGA
5dB, 6dB, OR 7dB
N
N
MAX9595
FILTER
FILTER
MIXER
FILTER
FILTER
FILTER
FILTER
SW/MONITOR
VCR_Y/CVBS_IN CLAMP
Figure 1. MAX9595 Video Section Functional Diagram