Agilent Technologies Agilent 34980A, User Manual

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152 34980A User’s Guide
4
Low Frequency Multiplexer Switch Modules
34925A 40/80-Channel Optically-Isolated FET Multiplexer
The 34925A 40/80- Channel Optically- Isolated FET Multiplexer (40/80- Ch
FET MUX) module is a high- speed and high- density FET MUX for high
throughput production test. This module is divided into two equal banks
of non- latching FET switches. This module also contains four armature
Analog Bus relays. Through ABus1 and ABus2 you can connect any of
the channels to the internal DMM for voltage or resistance
measurements. When the power is off, all channel and Analog Bus
relays open.
Using program commands or the mainframe front panel, you can control
each of the FET channel switches individually, and configure this module
for differential (2- wire or 4- wire) or single- ended (1- wire) mode.
Refer to the simplified schematics on
page 155 and page 158 .
If you are using an Agilent 349 xx T terminal block to connect your DUT
to this module, be sure to use the terminal block that corresponds to
your module configuration mode. Use the 34925T- 001 terminal block for
differential mode (2- wire or 4- wire configuration). Use the 34925T- 002
terminal block for single- ended mode (1- wire configuration). Refer to
drawings on
page 157 and page 160 .
You can confirm the mode in which your module is configured by using
the
SYSTem:CTYPe? <slot number> program command
.
This command
returns the identity of the plug- in module in the specified slot.
Two-Wire
• two independent 20- channel 2- wire MUXes. This configuration
requires neither using external wiring nor connecting through the
internal Analog Bus relays.
• one 40- channel, 2- wire MUX. You must use external wiring or connect
through the Analog Bus relays to for this configuration.
N O T E
Whenever you change from 2- or 4-wire mode to 1-wire mode, or
the reverse, you must cycle power on the 34980A for the
configuration to take effect.