MAX9526ATJ+ Maxim Integrated Products, MAX9526ATJ+ Datasheet - Page 10

• Manufacturer Part Number: MAX9526ATJ+
• Description: IC VID DECODER NTSC/PAL 32-TQFN
• Manufacturer: Maxim Integrated Products
• Type: Video Decoderr

Specifications of MAX9526ATJ+

• Applications: Automotive Systems, Players, TV
• Voltage - Supply, Analog: 1.8V
• Voltage - Supply, Digital: 1.8V
• Mounting Type: Surface Mount
• Package / Case: 32-TQFN Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Low-Power, High-Performance
NTSC/PAL Video Decoder
The MAX9526 is a simple, low-power video decoder
that converts all modes of NTSC and PAL composite
video signals to 10-bit YCbCr component video com-
patible with the ITU-R BT.656 standard. The device
powers up in fully operational mode and automatically
configures itself to standard NTSC or standard PAL.
An internal 10-bit, 54MHz ADC samples at four times
the sampling rate specified in ITU-R BT.601. The ana-
log front-end of the MAX9526 features a DC restoration
circuit, automatic gain control, and automatic offset cor-
rection. These blocks are controlled with digital pro-
cessing to accurately optimize the full-scale range of
the ADC. An integrated analog anti-aliasing filter elimi-
nates the need for off-chip filtering. The device includes
a 2:1 input multiplexer that can be configured to auto-
matically select the input based on activity.
The system clock is generated with an external 27MHz
crystal and an internal oscillator. Optionally, a 27MHz or
54MHz external clock can be connected to the
XTAL/OSC input. An internal line-locked digital PLL is
used to generate the 54MHz ADC sample clock that is
synchronous to the incoming video signal with up to
±5% variation in horizontal line length. The digital out-
put data and LLC clock are line locked to the video
input and provide a standard ITU output. The PLL can
also be configured to asynchronously sample the input
using the crystal oscillator or external clock.
The MAX9526 provides a 5-line adaptive comb filter to
separate the luminance (Y) and chrominance (C) video
components and reduce cross-chrominance and cross-
luminance artifacts. The MAX9526 operates with any
type of standard composite video signal source includ-
ing DVD players, video cameras, navigation systems,
and VCRs.
Figure 1. Analog Front-End
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______________________________________________________________________________________
V
V
V
REF
IN1
IN2
Detailed Description
ACTIVITY
DETECT
INTERNAL
BIAS
ANALOG
AGC
DC RESTORATION
DAC
ANALOG
The device powers up in fully operational video
decoder mode. An I
and enables programming of many decoder functions
including brightness, contrast, saturation, and hue. The
10-bit output can be reconfigured to provide 8-bit data
with separate horizontal and vertical syncs.
The MAX9526 AFE implements DC restoration, auto-
matic gain control (AGC), analog anti-aliasing filter
(LPF), activity detection, channel selection, and analog-
to-digital conversion. A block diagram of the AFE is
shown in Figure 1.
The MAX9526 continuously monitors activity at both
video inputs, V
channel is detected using the ADC output. On the
unselected channel an analog sync-tip clamp and sync
slicer are used to detect sync amplitudes greater than
50mV. In sleep mode, the analog sync-tip clamps and
sync slicers are used to detect activity on both inputs,
while the rest of the AFE is in a shutdown state.
The output of the activity detect circuit is reported
through the Status register 0x00. The user must manu-
ally select which video input to process by setting
INSEL in register 0x09 appropriately.
The MAX9526 can optionally be configured to automati-
cally select the video input that indicates the presence
of activity by setting AUTOSEL = 1 in register 0x09.
When activity is present on both V
power-up or when there is no activity on either input
channel, V
and there is no activity on V
When V
of activity, the input only switches to V
goes away on V
LPF
Activity Detect and Automatic Channel Selection
IN2
10-BIT
IN1
ADC
is automatically selected with the presence
is selected. When there is activity on V
IN1
IN2
10
.
and V
2
FILTERING
C register interface monitors status
CONTROL
DIGITAL
DIGITAL
Analog Front-End (AFE)
IN2
IN1
. Activity on the selected
10
, then V
TO DECODER
IN1
IN1
IN2
when activity
and V
is selected.
IN2
IN2
at