Instrument Overview And Troubleshooting Guide; Theory Of Operation - HP 8112A Operating, Programming And Servicing Manual

Instrument Overview and Troubleshooting Guide

Theory of Operation

H P - I B ,,,
I N P U T \
- C L O
COUNTER
BURST
OPTION
ON
CONTROL
The block diagram in Figure 10.1-l shows the HP 8112A at a
functional level.
MPU
A
DELRY
C K
PERU WC
. .
Figure 10.1-l. HP 8112A Functional block diagram
The microprocessor controls the operation of the instrument by
reading inputs from the front panel keyboard or the HP-IB, and
sending the appropriate data to the Digital-to-Analog Converters
front panel LEDs and display in response to the keyboard and HP-IB
inputs.
The generator hardware contains three specially developed HP ICs:
Timing IC
KEY BORRII
TRE
WIDTH LEE
.
W I D T H + SLOPES
This is used as triggerable pulse generators.
Three ICs are used, taking the external
signal applied to the Control Input and
applying Period, Delay and Width control in
successive stages to provide pulses for the
Slope IC.
1 0 . 1
OFFSET
AMPLITUDE
.
. .
A M P L I T U D E
TRIGGER
OUTPUT
TRIGGER
RNPLIFIER
10.1-l