What is an SMU (Source Measure Unit)?

Whether you work in electronics, high energy physics, nano materials, organic semiconductors, biological electronics or other related fields, current or voltage measurement is one of the most fundamental elements in the electrical evaluation of your project.

Conventionally, multiple single function instruments are being used to measure current and voltage of the device under test. However, this kind of setup makes it difficult to achieve reliable and consistent measurements due to the need to connect, control and synchronise multiple instruments with very different features and specifications. With the conventional multiple single function instruments setups, it is difficult to obtain a high level of measurement performance and accuracy.

The SMU or Source Measure Unit, is a single instrument that is capable of precisely sourcing and measuring current and voltage at the same time. It also makes the measurement setup more simple and accurate.

The SMU has a variety of features to enable accurate measurements and provides the users with a lot of benefits:

What is an SMU used for?

SMUs are used for current and voltage measurements requiring high accuracy, high resolution and flexible range. Such applications include I-V characterising and testing of various semiconductor devices such as Diodes and Transistors. In some cases, devices and materials require sourcing voltage and current across both positive and negative values:

Keysight B29xxA family of precision instruments

To help customers to solve their test challenges when high accuracy is needed, solutions from Keysight include:

- B2900A Precision Source/Measure Units family

- B2960A Low Noise Power Source

- B2980A Femto/Picoammeter

B2900A Precision Source/Measure Units family

The Keysight B2900A Series of Precision Source/Measure Units are compact and cost-effective bench-top Source/Measure Units (SMUs) with the capability to output and measure both voltage and current. The B2900A series of SMUs provide best-in-class performance at a lower price than ever before.

They have a broad voltage (210 V) and current (3 A DC and 10.5 A pulsed) sourcing capability, excellent precision (minimum 10 fA/100 nV sourcing and measuring resolution) and high measurement throughput. They also support an arbitrary waveform generation function.

In addition, the Keysight B2900A series possesses a superior graphical user interface with various viewing modes that dramatically improve test productivity, debug and characterisation.

The versatile integrated source and measurement capabilities of the B2900 series make them an ideal choice for testing semiconductors, active/passive components and a variety of other devices and materials. The B2900 series has a broad application range that spans from R&D and education uses to industrial development, test and manufacturing. Moreover, they work equally well as either standalone or system components.

The Keysight B2900A series consists of four models: the B2901A, B2902A, B2911A and B2912A, which are differentiated through their available features (number of digits displayed, measurement resolution, minimum timing interval, supported viewing modes, etc.) and by the number of SMU channels (one or two) that they contain. This makes it easy to select the exact price/performance point to meet your testing needs.

– Integrated voltage/current 4-quadrant precision source and measurement capabilities for easy and accurate I/V measurement

– Wide coverage up to 210 V, 3 A DC/10.5 A pulse

– 10 fA/100 nV minimum measurement resolution (6½ digits)

– 10 fA/100 nV minimum sourcing resolution (6½ digits)

– High resolution arbitrary waveform generation (AWG) and list sweep functions (10 μs minimum interval)

B2960A Low Noise Power Source

The general trend in electronics is for equipment and devices to become smaller, integrated and more portable. More intelligence, integration and miniaturisation are demanded along with lower power consumption to maximise battery life. Researchers, designers and developers pursuing the innovations and breakthroughs needed to develop these next-generation devices typically require basic equipment such as power supplies and sources for this work. Therefore, the power supplies and sources used by these innovators also need to possess features that are advanced enough to meet the difficult measurement challenges that they often face.

The Keysight B2900A series of precision instruments includes two next-generations of power supply/source solutions that meet these needs: the B2961A 6.5 Digit Low Noise Power Source 1ch and the B2962A 6.5 Digit Low Noise Power Source 2ch. These products achieve best-in-class precision, support wide bipolar output ranges and have an extremely low noise floor. They also possess graphing capability and other advanced features. This makes them ideal companion products for other instruments such as oscilloscopes, network analysers, spectrum analysers, frequency counters, digital multimeters, nanovoltmeters etc.

– The world’s only 6.5 digit resolution power source with a bipolar sourcing range from 100 nV to 210 V and 10 fA to 3 A (DC)/10.5 A (pulsed)

– Optional ultra-low noise filters can reveal your device’s true characteristics with low noise performance (10 μVrms from 10 Hz to 20 MHz, 1 nVrms/10 kHz)

– Supports both pre-defined and user-defined arbitrary waveform generation (1 mHz to 10 kHz)

– Output voltage and current can be verified quickly using the built-in 4.5 digit voltage/current monitor

B2980A Femto/Picoammeter

Keysight's B2980A Series of Femto/Picoammeters and Electrometers/High Resistance Meters not only offer best-in-class measurement performance, but also provide unprecedented features to maximise your measurement with confidence!

The Femto/Picoammeters and Electrometers both offer 0.01 fA (10-17 A) minimum current resolution, which meets virtually all existing and future low-level current measurement needs. The electrometers feature a 1,000 V voltage sourcing capability that supports up to 10 PΩ (1016 Ω) resistance measurements. The electrometers also work with Keysight’s well-proven high resistance meter accessories.

Both the Femto/Picoammeter and Electrometer have battery-powered versions to eliminate AC power line noise. This available capability provides an unmatched level of noise reduction, enabling low-level measurements that were previously impossible.

Unlike conventional picoammeters and electrometers, the B2980A series has a 4.3” colour LCD-based graphical user interface (GUI) that provides multiple options for viewing data. In addition to numeric format, data can also be viewed as a graph, histogram and trend chart. These unique front-panel capabilities facilitate the capture of transient behaviour and provide the ability to make quick statistical analysis without the need for a PC.

The B2980A series also has features to help you maintain measurement integrity on the external cabling and fixturing. The available Setup Integrity Checker software enables the comparison of noise levels for different cabling and fixturing arrangements; allowing you to identify and isolate the noise-sensitive areas in your measurement system.

In addition to these impressive measurement capabilities, the B2980A series has easy-to-use and convenient measurement-assist functions which lets users with limited or no electrical engineering training to perform complicated electrical characterisation operations with ease.

For more information on the B2900 Precision Instrument Family, see this link.

And click here to watch various videos that showcase the B2900 measurements.