Fluke PM6690, Service Manual, Page: 27 / 200

Block Diagram Description 4-5
ON/OFF
RESET
MICROPROCESSOR
ARM 7
STD OSC
OPT OSC
100 MHz
PLL
FAN
STDBY
LED
KEYBOARD
LCD
TEMP
SENSOR
USB
GPIB
GATE LED
TRIG LED A
TRIG LED B
INT REF OUT
INTERPOLATORS
4 X
EXT CTRL IN
EXT REF IN
TRIG LVL
INPUT
AMPLIFIERS
PRESCALER
MEASURING LOGIC
(FPGA)
LVL
CONV
LINE
PWR
AC/DC
SEPARATE BOARD
+15 V
-15 V
+5 V
POWER
SUPPLY
+15 V
+12 V
+5 V
-12 V
-5.2 V
-2.1 V
+3.3 V
+2.5 V
+1.8 V
JTAG
I C
2
DISPLAY BOARD
SPI
SPI
C
A
B
OPTION
DISPLAY BOARD
*
*
*
*
*
*
REAR PANEL CONNECTORS
-FLASH 8 MB
-SDRAM 32 MB
MEMORY
Figure 4-1
Block diagram of the '90'.