NAD C541, Service Manual, Page: 17 / 32

AMPLIFIER 1
OUTPUT
INVERTING
INPUT
NON-INVERTING
INPUT
V –
AMPLIFIER 2
V +
OUTPUT
INVERTING
INPUT
NON-INVERTING
INPUT
1
2
3
4
8
7
6
5
+ – – +
19
U305-U306: OPA2604
1 A1 14 VCC
2 B1 13 B4
3 Y1 12 A4
4 A2 11 Y4
5 B2 10 B3
6 Y2 9 A3
7 GND 8 Y3
P1 OUT1 VCC2 OUT2 P2
3 2 8 10 9 7
4
5
1
6
VCC1
VZ
IN1
GND
IN2
Predriver
Input logic circuit
U403: 74HC00 U701: LB1641
P17/PWM P16/BUZ P15/SCK1 P14/SI1/SB1 P13/SO1 P12/SCK0 P11/SI0/SB0 P10/SO0 P07 P06 P05 P04 P02 P03 P01 P00
S0/T0
S1/T1
S2/T2
S3/T3 S4/T4 S5/T5 S6/T6 S7/T7 S8/T8 S9/T9
S10/T10 S11/T11 S13/T13 S12/T12 S14/T14 S15/T15
S29
S28
S27
S26
S25
S24
S23
S22
S21
S20
S19
S18
S17
S16
VP
VDDVPP
TEST 1
RES
XT1
XT2
VSS
CF1
CF2
VDD
P80/AN0
P81/AN1
P82/AN2
P83/AN3
P70/INTO
P71/INT1
P72/INT2/TOIN
P73/INT3/TOIN
48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
32
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
Interrupt Control
Stand-by Control
Bus Interface
Port1
Port7
Port8
Base Timer
SIO0
SIO1
Timaer 0
Timaer 1
ADC
Bus
Bus
IR PLA
ROM
PC
ACC
B Reg
PSW
RAR
RAM
Stack Pointer
PORT 0
Watcher Dog Timer
C Reg
ALU
INT0-3
Noise Filter
Real Time
Service
XRAM
(128 bytes)
VFD Controller
High Voltage
Output
Clock
Generator
CF
RC
X'tal
U401: LC866008C IC401: System Block Diagram LC8660/08C