HP 8712C - Page 337

I
-
Automating Measurements
Controlling Peripherals
The data will typically remain valid until the next write to the parallel port,
but you should always latch the data using the strobe. Figure 7-10 shows a
simple circuit which can be used to write to an f&bit DAC and a digital latch
DECODE
5
6
7
DAC0830
> WRI
Rfb
DO
D7
ILE
---
CS.vmZ.YFER
p
“OUT
+
OP AMP
2
DO
I
3
Dl
1
T I I
4 ,
D2
I I I
I I I
LATCHES
‘174
L
PARALLEL
PORT
De-25
CONNECTOR
NOTE: ESD PROTECTION, POWER SUPPLIES AND DECOUPLING ARE NOT SHOWN.
Figure 7-10. Digital latch Circuit
7-58