Onkyo TX-SR804, Service Manual

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TX-SR804/804E
IC BLOCK DIAGRAMS AND TERMINAL DESCRIPTIONS -24
Q4004: LC74763-9836 (On-Screen Display IC)
TERMINAL DESCRIPTION
Pin No. Symbol Function Description
1 VSS Ground Ground connection
2 Xtal IN1
Crystal oscillator connection
Connection for the crystal and capacitor used to form the crystal oscillator that generates
the internal synchronization signal. The oscillator can be selected with a command switch.
3 Xtal OUT1
4 HSYNC OUT
Horizontal synchronization Outputs the horizontal synchronization signal (AFC). The output polarity can be selected
output (metal option). Also functions as general output port (command switch).
5 Xtal IN2
Crystal oscillator connection
Connection for the crystal and capacitor used to form the crystal oscillator that generates
the internal synchronization signal.
6 Xtal OUT2
7 VSYNC OUT Vertical synchronization output
Outputs the vertical synchronization signal. The output polarity can be selected (metal
option). Also functions as general output port (command switch).
8 CS Enable input
Enables/disables serial data input. Serial data is enabled when this pin is low (hysteresis
input). Pull-up resistor built in (metal option).
9 SIN Data input Serial data input (hysteresis input). Pull-up resistor built in (metal option).
10 SCLK Clock input Clock input for serial data input (hysteresis input). Pull-up resistor built in (metal option).
SECAM mode switch input/
During input, switches between SECAM and other modes.
11 SECAM
output (command switch)
During output, functions as general output port or internal V output (command switch).
Low = other modes, high = SECAM mode
525/625 switch input/output
During input, switches between 525 scan lines and 625 scan lines.
12 525/625
(command switch)
During output, functions as general output port or character data output (command switch).
Low = 525 lines, high = 625 lines
NTSC/PAL switch input/output
Switches the color mode between NTSC and PAL.
13 NTSC/PAL
(command switch)
During output, functions as general output port or frame data output (command switch).
Low = NTSC, high = PAL
Switch FSC between 3.58 MHz and 4.43 MHz.
14 3.58/4.43 3.58/4.43 switch input/output During output, functions as general output port or halftone output (command switch).
(command switch) Low = 3.58, high = 4.43
15 RST Reset input
System reset input pin, low is active (hysteresis input).
Pull-up resistor built in (metal option).
16 CVOUT Video signal output Composite video output
17 V DD2 Power supply connection Power supply connection for composite video signal level generation
18 CV IN Video signal input Composite video input
19 CV CR Video signal input SECAM chroma signal input
20 SYNC IN Sync separator circuit input Built-in sync separator circuit video signal input
21 SEP C Sync separator circuit Built-in sync separator circuit
22 V SS Ground Ground connection
23 PD OUT Control voltage output AFC control voltage output
24 AMP IN
AFC filter connection Filter connection
25 AMP OUT
26 FC Control voltage input AFC control voltage input
27 VCOIN
LC oscillator connection VCO LC oscillator circuit coil and capacitor connection
28 VCOOUT
External synchronization signal
Outputs the exclusive NOR of the horizontal synchronization signal (AFC) and CSYNC (sync
separator). The output polarity can be selected (metal option). Also functions as general
output port (command switch).
29 SYNCDET
detection output
30 VDD1 Power supply connection Power supply connection (+5 V: digital system power supply)