NAD T 761 - Key Board & Tuner Board IC Block Diagrams

51
KEY BOARD
U202: AT24C02
TUNER BOARD
U901: LA1837
DOUT
ACK
WORD ADDRESS
BUFFERS
START/STOP
LOGIC
CONTROL
LOGIC
STATE COUNTERS
SLAVE
ADDRESS
COMPARATOR
A0
A1
A2
SCL
WP
SDA
VSS
VCC
XDEC
DATA IN STORAGE
HIGH VOLTAGE/
TIMING CONTROL
E
2
PROM
COLUMN
DECODERS
SENSE AMPS
SHIFT REGISTERS
VCCA0 81
WPA1 72
SCLA2 63
SDAVSS 54
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
30 29 28 27 26 25 24 23 22 21 20 19 18 17 16
ALC
AM
OSC
AM
MIX
AM
RF.AMP
REG
AGC
AM IF
AM
S-METER
TUNING
DRIVE
STEREO
DRIVE
V
CC
V
CC
AM/FM
IF-BUFF
FM
S-METER
S-CURVE
AM IF
FM
DET
GND
FM IF INPUT
AM MIXER
OUTPUT
FM IF INPUT
BYPASS
AM IF INPUT
GND
TU-LED
ST LED
AM-IF OUTPUT
FM DETECTOR
AM NARROW CF
FM S-METER
OUTPUT
AM S-METER
OUTPUT
MUTE
FM/AM
SWITCH
PILOT V
CO
SD
COMP
DET
BUFF
DECODER
ANTI-BIRIDE
3 rd 5 th
STEREO
SW
MUTE
VCO
304kHz
FF
38k
P-DET
Ø
FM SD ADJ OSC REG AM RF INPUT AFC AM AGC AM DETECTOR INPUT FM DETECTOR OUTPUT MPX IUTPUT MPX OUTPUT MPX OUTPUT FM STEREO L INPUT FM STEREO R INPUT L-OUT R-OUT
FF
19k
FF
19k
PILOT
DET