Keysight 34970A - 34902 A 16-Channel Multiplexer; 34908 A 40-Channel Multiplexer

22 | Keysight | 34970A Data Acquisition/Switch Unit Family - Technical Overview
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34902A
16-Channel High-Speed Multiplexer
– Scanning up to 250 ch/s
– Two- and four-wire scanning
– Built-in thermocouple reference junction
The Keysight 34902A employs reed relays to
achieve scan rates up to 250 channels per second�
Use this module for high-throughput automated
test applications as well as high-speed data
logging and monitoring tasks�
Sixteen two-wire inputs switch up to 300 V�
Two- and four-wire channels may be mixed on the
same module� User provided shunt resistors are
required for current measurements�
34908A
40-Channel Single-Ended Multiplexer
– 60 ch/s scanning
– Single-wire switching for common low
applications
– Built-in thermocouple reference junction
Use the Keysight 34908A for the greatest density in
common low applications, such as battery test,
component characterization, and benchtop testing�
Each module switches 40 one-wire inputs� All two-
wire internal measurements except current are
supported� The module low connection is isolated
from earth and can float up to 300 V�
Backplane switches
Internal
DMM input
01
08
Com
Com
(4W sense)
09
16
Internal
DMM input
(4W sense)
Reference
junction
sensor
Channel switches
Bank switch
H
L
H
L
T
H
L
H
L
H
L
H
L
H
L
H
L
01
20
21
40
Com
Com
H
H
L
H
H
H
L
H
Channel switches
Backplane
switch
Bank switch
Internal
DMM input
Reference
junction
sensor
T
Note: Thermocouples must be electrically
isolated from each other to avoid current
loops and subsequent measurement errors.
Note: Not recommended for connection to ac line without
external transient suppression.