Product(s):

SourceMeter Instruments:2400, 2410, 2420, 2425, 2430, 2440

Source-Measure Units: 236, 237, 238

Question: What are the significant differences between the Model 236 Series Source-Measure Units and the Model 2400 Series SourceMeter Instruments? 

Answer:

First a few similarities . . . the Model 236 Series Source-Measure Units (SMUs) and the Model 2400 Series SourceMeters both offer four quadrant operation, the ability to source or sink voltage or current. Both were designed to source current and measure the voltage drop across a load or source voltage and measure the current draw through the load. Neither was designed to source voltage or current in one part of the circuit and measurement in another part of the circuit. Both the 236 Series and the 2400 Series instruments have measure-only modes.

There are several differences between the Model 236 SMUs and the Model 2400 SourceMeters:

1. Voltage Range – The Model 236 Series includes instruments with voltage source and measure capabilities ranging from 100V to 1100V. The minimum voltage source step size is 100uV and the maximum measurement resolution is 10uV. The 2400 SourceMeter Series includes instruments with voltage source and measure capabilities ranging from 200V to 1100V. The minimum voltage source step size is 5uV and the maximum measurement resolution is 1uV. Please see the specifications of these instruments for additional details.
2. Current Range – The SourceMeter series products have maximum current ranges of 1A, 3A, 5A and 10A (pulse only). The base Model 2400 has a minimum current source step size of 50pA and a maximum measurement resolution of 10pA. The Model 236 has a minimum current range of 1nA and a maximum current range of 110mA. With such low current measuring capability, the Model 236 offers electrometer-like measurement and can also be used for sourcing pA level currents.The low current capability of the 236 is an important decision-making feature when deciding between the 2400 or 236 Series instruments. Please see the specifications of these instruments for additional details.
3. Source-Measure Programming – The Model 236 can be used to (1) source voltage and measure current or (2) source current and measure voltage. Measurements cannot be disabled. The Model 2400, may measure voltage, current and resistance while sourcing voltage or current. Measurements may be disabled under computer control.
4. Sweep Capabilities – The 236 series SMUs have fixed level staircase (linear and logarithmic) as well as ‘pulse’ sweeps.The Model 2400 offers staircase sweeps with both linear and logarithmic steps, a custom list sweep and source-memory sweep.
5. Data Storage – Both the 236 and 2400 offer internal nonvolatile buffer storage.The 236 may store a maximum of 1000 readings of sweep data. No readings may be stored of non-sweep data.The Model 2400 may store a maximum of 2500 readings.Buffer storage may be enabled at any time.
6. Connectors – The 236 SMUs have 3-lug triax connections for sense and output terminals.Connection is made to the 2400 SourceMeters via banana jacks.
7. Programming Syntax - The SourceMeters are SCPI compliant (Standard Commands for Programmable Instruments), whereas the 236 series uses DDC (Device-Dependent Commands). DDC syntax is the “R2D2” type where the instrument is programmed using codes of letters and numbers.

A Few Additional Notes –

The Model 2400 Series SourceMeters offer other features not available on the 236 including limit testing, digital I/O with handler interface, contact check, 6-wire ohms testing and a variety of output-off states.

If the designer is interested in a solution with the source/measure capabilities of the 236 but with features unique to the SourceMeter line, he or she might consider the Model 6430 Sub-Femto Amp SourceMeter.