Agilent Technologies Switch/Measure manual 34925A 40/80-Channel Optically-Isolated FET Multiplexer

Low Frequency Multiplexer Switch Modules 4

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 130 and page 133.

If you are using an Agilent 349xxT 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 132 and page 135.

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.

NOTE	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.

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.

34980A User’s Guide 127