cxa3516r Sony Electronics, cxa3516r Datasheet - Page 41

• Manufacturer Part Number: cxa3516r
• Description: 3-channel 8-bit 165msps A/d Converter Amplifier Pll
• Manufacturer: Sony Electronics

Amplifier
This is a 3-channel AMP that optimizes the AC coupled RGB analog input signals and YCbCr analog input
signals for ADC input. Switch input mode between RGB input or YCbCr input with the control register. The
AC coupled analog input signals are synchronously clamped by the externally input clamp pulse at a
pedestal level. An input capacitor of 0.1µF is recommended.
Allowing two lines of input to be selected for the analog input signal, the AMP includes a high frequency, low
cross talk video switch circuit for input switching. Switching is performed using a control register. When using
only one line, leave the unused line open.
The input band of the analog input signal is 220MHz in the –3dB bandwidth range.
There are main contrast and sub-contrast of the gain used to adjust the analog input signal to full scale (1V
typ.) of the ADC. Each can be adjusted to one of 256 levels using control registers. Main contrast is
controlled by moving the gain of the 3 RGB channels. The each gain of the 3 RGB channels can be
controlled independently.
In RGB input mode, the clamp level used for the black level adjustment can be adjusted independently for
the 3 channels to any of 256 levels by using sub-brightness.
The CLP pin
of 0.1µF is recommended.
The OUT pins
the two lines of input select switch. Either of them can be selected by control register. As for emitter follower
output, since the internal bias current is small, be sure to connect an 820
and AGND in order to view the signal with a high frequency. A 75
load capacitance should be 5pF or less.
When the SYNC ON GREEN signal is monitored at the OUT pins
sync amplitude is a maximum of 0.3V, for a limiter is applied at the amplifier input stage.
In YCbCr signal input mode, Y can be adjusted to any of 256 levels using the sub-brightness while Cb and Cr
can be adjusted to any of 64 levels using the Cb or Cr offset.
A detailed description of the above registers is given below.
• Analog input signal mode switching
• Input channel switching
• Clamp pulse input polarity
Analog input signal supports both RGB analog input signal and YCbCr analog input signal.
This register switches the clamp level of the input clamp block and the amplifier output block in each mode.
However, the G/Ych perform the same processing in both RGB input mode and YCbCr input mode.
Input supports 2-channel input, and the input can be selected by an internal switch.
The clamp pulse input polarity can be selected by an internal switch.
Analog input signal channel switching
1
2
Analog input signal mode
CLP pins: Overall naming for R/Cr CLP (Pin 130), G/Y CLP (Pin 128), B/Cb CLP (Pin 129)
OUT pins: Overall naming for R/Cr OUT (Pin 3), G/Y OUT (Pin 143), and B/Cb OUT (Pin 1)
Register: RGB In Select
Register: YCbCr mode
Clamp pulse polarity
Register: CLP POL
1
is connected to the hold capacitor of the clamp circuit for the sub-brightness. A hold capacitor
2
can output signal immediately before input to the ADC or the signal after switching between
NEGATIVE
RGB input
IN1
0
0
0
– 41 –
YCbCr input
POSITIVE
IN2
1
1
1
2
driver cannot be supported. In addition,
after the two lines of select switch, the
resistor between the OUT pins
CXA3516R
2