HP 8562E - Page 304

11. Monitor A3U401B pin 7 (LIF-STB) with
an oscilloscope or logic probe. This is the strobe
for the A5 IF assembly.
12. Press (AMPLITUDE] and check that pulses occur when toggling between REF‘ LVL settings of
-10 dBm and -20 dBm.
13. Monitor A3U401B pin 9 (LLOGSTB) with an oscilloscope or logic probe. This is the
strobe for the A4 log amplifier/Cal oscillator assembly.
14. Press (Wj and check that pulses occur when toggling between LINEAR and
Lac mfm.
Interface Strobe Select
Refer to function block K of A3 Interface Assembly Schematic Diagram in the
HP 8560 E-Series Spectrum Analyzer Component Level Information.
Interface strobe select generates the various strobes used by circuits on the A3 Interface
Assembly. Table 8-10 and Table 8-11 are the truth tables for demultiplexers A3U410 and
A3U500.
Table 8-10. Demultiple :er A3U410 Truth Table
Selected Output Line
IA1
Pin 15, LSCAN-KBD
L
Pin 14, LDACUl
H
Pin 13, LDACl
L
Pin 12, LDAC2
H
Pin 11, LDACS
L
Pin 10
H
Pin 9, LTIMER
L
Pin 7, LADC-REGl
H
Table 8-l 1. Demultiple
Selected Output Line
IA0
Pin 15, LSENSE-KBD
L
Pin 14, LINT-PRIOR
H
Pin 13, LADC-DATA1
L
Pin 12, LDAC-DATA0
H
Pin 11, HCNTR-LDO
L
Pin 10, HCNTR-LDl H
Pin 9, LRPG-RD
L
Pin 7, LADC-REGO
H
IA2 IA3
L L
L
L
H L
H L
L
H
L H
H H
H H
:er A3U500 Truth Table
IA1 IA2
L L
L L
H L
H
L
L
H
L H
H
H
H
H
8-30 ADC/lnterface Section