Digital Circuitry Block Diagram; Power Supply Circuits - Keithley 2000 Repair Manual

Table 2-1

Power supply circuits

Supply
+5VD
+37V
+15V
-15V
+5V, +5VRL
Digital circuitry
Refer to Figure 2-2 for the following discussion on digital circuitry.
Figure 2-2
Digital circuitry
block diagram
Circuitry
(See Figure 2-3)
Rectifier
CR104
CR116, CR117
CR102
CR102
CR103
O
P
XADTX
T
Analog
O
XADCLK
XADTS
I
S
O
XADRX
AT101
U150
U155
Scan Control
Trigger
U146, U164
Trigger
Link
Filter Regulator
C128, C156 U144
C104, C108 U101
C148 U125
C131 U119
C146 U124
ROM
NVRAM
U156, U157
U136
ADTX
ADCLK
68306
µP
ADTS
U135
ADRXB
TRIG IN
TRIG OUT
Data IN
Data OUT
Troubleshooting
RAM
U151, U152
Keypad
Display Board
Controller
U401
XTAL
Y101
IN
RS-232
RS-232
OUT
Port
U159
GPIB
IEEE-488
U158, U160,
U161
2-7
Display
DS401
Bus