The Keithley 236, 237, and 238 Source-Measure Units (SMU) are fully programmable instruments, capable of sourcing and measuring voltage or current simultaneously. These systems are really four instruments in one: voltage source, current source, voltage measure, and current measure.
Keithley 238 Specs
- SOURCE-MEASURE UNIT: Sources voltage while measuring current, or sources current while measuring voltage.
- FUNCTION: Can be used as DC source or meter, sweep source, or full source-measure unit.
- SOURCE-DELAY-MEASURE CYCLE: Default Delay: Fixed delay for instrument settling. User Delay: Additional delay for device under test or system capacitance.
- MEASURE: Integration Time Fast: 416 µs 4-digit resolution Medium: 4 ms 5-digit resolution Line Cycle: 16.67 ms (60 Hz) or 20.00 ms (50 Hz), 5-digit resolution Elapsed Time: Measures and stores time from sweep trigger to measurement complete for each step of sweep.
- RANGING: Source: Auto-ranging through keypad entry; fixed range selection using rotary dial and SELECT keys (DC function). Fully programmable in SWEEP function. Measure: Auto or fixed range. Fixed range selection made by choice of COMPLIANCE value.
- FILTER: Takes n measurements, calculates and outputs average (n = 2, 4, 8, 16, or 32, selectable).
- SUPPRESS:Subtracts displayed measurement from subsequent readings.
- MENU: DC Measurement Delay, Default Delay On/Off, Local/Remote Sense, 50/60Hz, IEEE Address, Self Tests.
- DATA ENTRY: Numeric keypad or detented rotary dial.
- TRIGGER: Input and Output: Set for any phase of SOURCE-DELAY-MEASURE sequence or trigger output at end of sweep. Origin: Internal, External (including front panel MANUAL TRIGGER button), IEEE-488 bus (TALK, GET, "X").
- MEMORY: Stores one full sweep (up to 1000 points) of source, delay, and measure values, elapsed times, and sweep parameters. Lithium battery backup.
- INTERLOCK: Use with test fixture or external switch. Normally closed; open puts instrument in standby.