– 76 –
Pin No.
Pin Name
I/O
Function
43
AVRH
I
Reference voltage (+5V) input terminal (for A/D converter)
44
AVRL
I
Reference voltage (0V) input terminal (for A/D converter)
45
AVSS
—
Ground terminal (for A/D converter)
46
KEY-IN0
I
Key input terminal (A/D input) (LSW531, LSW532, S502, LSW533 to LSW538)
OFF, SOURCE, SEEK/AMS
+
)
+
=
0
– , DSPL, SOUND, MODE, SHIFT, 1, 2
keys input (LSW533 DSPL: MDX-C7970R only)
47
KEY-IN1
I
Key input terminal (A/D input) (LSW890, LSW512 to LSW521)
6
, AF/TA (MDX-C7970R) LIST (MDX-C7970), LIST PTY (MDX-C7970R) DSPL (MDX-
C7970), 10 to 3 keys input
48
KEY-IN2
I
Key input terminal (A/D input) Not used (fixed at “L”)
49
RC-IN0
I
Rotary remote commander key input terminal (A/D input)
50
D-BASS IN
I
D-BASS switch (S501) input terminal (A/D input)
51
QUALITY
I
Noise level detection signal input at SEEK mode (A/D input)
Used for the MDX-C7970R only (MDX-C7970: Not used (open))
52
MPDH (MTP)
I
Multi-path detection signal input from the RDS decoder (IC102) (A/D input)
Used for the MDX-C7970R only (MDX-C7970: Not used (open))
53
S-METER
(VSM)
I
FM and AM signal meter voltage detection input from the FM/AM tuner unit (TU1)
(A/D input)
54
VCC
—
Power supply terminal (+5V)
55
AMP ATT
O
Power amp muting on/off control signal output to the power amplifier (IC500)
“L”: muting on
56
AMP ON
O
Standby on/off control signal output to the power amplifier (IC500)
“L”: standby mode, “H”: amp on
57
ILL IN
I
Auto dimmer control illumination line detection signal input terminal
“L” is input at dimmer detection
58
LOCK IN
I
Mini-disc lock detection signal input from the MD mechanism controller (IC501) “H”: lock
59
EMPH ON
O
Emphasis control signal output terminal Not used (open)
60
AU ATT
O
Audio line muting on/off control signal output terminal “H”: muting on
61
AF ATT
O
Preamp muting on/off control signal output to the electrical volume (IC300) “H”: muting on
62
TU-ATT
O
Muting on/off control signal output of the FM tuner signal “H”: muting on
Used for the MDX-C7970R only (MDX-C7970: Not used (open))
63
VSS
—
Ground terminal
64
ACC IN
I
Accessory detect signal input terminal “L”: accessory on
65
AF-SEEK
O
PLL low-pass filter time constant selection signal output at AF SEEK
“H” is output when AF SEEK Not used (open)
66
WIDE
O
67
DAVN
I
Data transmit completed detect signal input from the RDS decoder (IC102) “H” active
Used for the MDX-C7970R only (MDX-C7970: Not used (open))
68
NARROW
O
Narrow select signal output terminal “H” active
Used for the MDX-C7970R only (MDX-C7970: Not used (open))
69
SSTOP
I
IF counter request signal input from the FM/AM PLL (IC100)
70
SDA
I/O
Two-way data bus with the FM/AM PLL (IC100), RDS decoder (IC102) and electrical volume
(IC300) (RDS decoder is MDX-C7970R only)
71
SCL
O
Bus clock signal output to the FM/AM PLL (IC100), RDS decoder (IC102) and electrical volume
(IC300) (RDS decoder is MDX-C7970R only)
72
RC-IN1
I
Rotary remote commander shift key input terminal “L”: shift
73
X1A
O
Sub system clock output terminal (32.768 kHz)
IF band select signal output terminal “H”: wide mode
In receiving FM signals, interference noise from adjacent stations is removed by narrowing the
IF band automatically in the tuner unit so as to raise the selectivity, but in this case, the distortion
may increase and accordingly, the IF band is widened forcibly
Used for the MDX-C7970R only (MDX-C7970: Not used (open))
Summary of Contents for MDX-C7970/C7970R
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Page 41: ... 61 4 20 SCHEMATIC DIAGRAM SUB Board MDX C7970 C7970R Page 54 Page 57 ...
Page 48: ... 68 6 IC700 X1 KEY Board 1 IC801 º OSC IN 5 8 Vp p 271 ns 2 8 Vp p 3 5 µs ...
