cxa3516r Sony Electronics, cxa3516r Datasheet - Page 45

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

SYNCSEP
The SYNCSEP function can be used to separate and output the SYNC signal that is superimposed on the
SYNC ON GREEN signal (including the SYNC ON Y signal).
There are two major SYNCSEP circuits. One is the circuit for creating a SYNC signal to be input to the PLL,
and the other is a circuit for outputting a SYNC signal from the SOGOUT (Pin 105) so that a clamp pulse can
be created externally. These SYNCSEP circuits perform processing on entirely different channels.
(See the block diagram for the SYNCSEP operational description.)
• SYNCSEP circuit for the PLL SYNC signal
In the case of the SYNC ON GREEN signal, the SYNC ON GREEN signal is AC coupled to the G/YIN1 (Pin
124) or the G/YIN2 (Pin 126) and the sync component is separated and used as a reference. An input
capacitor of 0.1µF is recommended.
When a signal is input to this pin, the pedestal level is clamped by a clamp pulse input to the CLPIN (Pin
113). After this, the signal is split into a signal to the amplifier circuit and the signal to the SYNCSEP
circuits, and the SYNC signal is sent through a two lines of input select switch (SW SOGP) and the SYNC
signal is separated by the SYNCSEP circuits. At this time, it is possible to minimize the jitter of the SYNC
signal sent to the PLL by using a control register to select the threshold level (V
(V
SOG SYNC SEP threshold (Versus pedestal level)
SOG SYNC SEP hysteresis
The SYNC signal separated by the SYNCSEP circuits can be switched at the SW PLL circuit with an
externally input SYNC signal (the SYNC signal input from the SYNCIN1 or SYNCIN2 pin) by using control
registers (SYNCP/HSYNC). The selected signal is input to the PLL block.
Selecting between the sync separated SYNC signal and the externally input SYNC signal
Register: SYNC SEP V
SYNC signal type
SYNC signal input pin
HYS
Register: SYNC SEP V
Register: SYNCP/HSYNC IN
) of the SYNCSEP circuit according to the type of noise on the superimposed SYNC signal.
Hysteresis
Threshold
HYS
TH
75mV
0000
2mV
00
Sync separated signal
G/YIN1 pin
G/YIN2 pin
9.3mV step
20mV
01
· · ·
0
– 45 –
45mV
215mV
10
1111
Externally input SYNC signal
SYNCIN1 pin
SYNCIN2 pin
70mV
11
V
V
HYS
1
TH
SYNC signal
TH
) and hysteresis level
Pedestal level
CXA3516R