SpikeSafe Source Measure Unit

What Is a Source Measure Unit (SMU)?
A Source Measure Unit (SMU) is a precision electronic instrument that combines a power source and measurement system in a single device. It can simultaneously supply current to a device under test while accurately measuring the resulting electrical response. The capabilities of an SMU are commonly used in semiconductor devices testing, materials research, and component characterization. It allows users to perform tasks such as IV (current-voltage) characterization, leakage testing, and device reliability analysis with minimal setup complexity. With Vektrex SMU instrument, improve your measurements with precision and accuracy, achieve repeatability and reduce the cost of test.
Precise and Repeatable Measurements
The SpikeSafe Source Measure Unit is optimized for high-precision and repeatable measurements, making it suitable for use in both laboratory and production environments worldwide. Vektrex, the company behind this technology, also developed the Control Panel software application, which offers a user-friendly interface for operating the SMU.
Which Source Measure Unit Is Right For Me?
Here at Vektrex, we give users to pick from a standard SMU or a high current SMU. The standard SMU currently ranges from 50 mA to 10 A. The high current SMU currently ranges from 10 A to 80 A. The option narrows down to your device under test, pick the current range required to complete your test.

Standard Source Measure Unit
Options available: 50 mA, 500 mA, 4 A, 5 A, 10 A
Lower-current models (50 mA and 500 mA) are ideal for sensitive device research (i.e. micro-LEDs). Meanwhile, mid-range (4 A and 5 A) and high-current (10 A) units support a higher power electronics, and industrial testing.
- 100% duty cycle
- Minimum pulse width available: 1 µs
- Max voltage range: 50V to 400 V
- Dual-digitizer option
- Vektrex Control Panel ready
- Production ready

High Current Source Measure Unit
Options available: 10 A, 20 A, 40 A, 60 A, 80 A
The Vektrex high-current Source Measure Unit (SMU) range from 10 A to 80 A is designed for demanding power electronics, materials, and industrial device testing where precise control must be maintained under high load conditions.
- Parallel high current models together for higher current applications.
- DC and Pulsed modes
- Max voltage range: 50V to 400V
- Dual-digitizer option
- Vektrex Control Panel ready
The Preferred SMU
One of the standout features of SpikeSafe SMUs is their capability to achieve minimum pulse widths as low as 1 microsecond (1 µs). This is crucial for reducing junction temperatures in sensitive semiconductor devices such as Vertical-Cavity Surface-Emitting Lasers (VCSELs), laser diodes, and other semiconductor components.
Continuous Power Conversion Means Higher Voltage
Vektrex’s proprietary continuous-power-conversion technology enables a single SpikeSafe SMU to power a wide range of devices with sustained output power, without duty cycle limitations. This is particularly advantageous for high-power applications, as the SpikeSafe SMU can operate at voltages significantly higher than the typical 10V to 60V limitation of standard pulsed SMUs. This flexibility makes the SpikeSafe SMU suitable for both low and high-power applications, providing researchers and engineers with a powerful tool for precision testing and characterization.
Beat The Heat
Device junction heating distorts measurements, causing L-I curves to droop and shifting I-V curves. With Vektrex’s fast pulsing SMUs you can make your measurements before heat builds up, revealing true device characteristics.

Test What You Couldn’t See
With more and more high-power density LED and laser devices coming to market, there’s a gap between what can tested with traditional source measure units and present engineering and production testing needs. Inadequate power, pulsing and measurement capabilities limit previous-generation source measure units.
SpikeSafe® SMU precision pulsed source measure units close that gap by providing accurate pulsing from hundreds of seconds down to 1us with sustained output power. SpikeSafe SMU combines the speed and power needed for LED and laser testing with integrated high-speed digitizing measurement. Now you can accurately test what you previously couldn’t test, and see what you didn’t have the power to see – with remarkable repeatability.
Introducing “Crazy Stable” Measurements
SpikeSafe SMUs provide the power needed for more accurate, efficient, and repeatable measurements.
Submicrosecond to low microsecond rise/fall times, programmable load tuning and on-the-fly pulse width correction combined mean the device under test experiences less heating and more uniform heating. The result is unmatched measurement stability – measurements one beta site evaluator described as “crazy stable”.

With measurement stability, multiple measurements and averaging are not required. With measurement stability, false positives and false negatives are eliminated, improving yield and reducing the cost of test.
True Differential Digitizer
Vektrex’s SMU uses advanced true-differential digitizer technology to produce time-aligned measurements required by measurement standards. Common mode noise present with other measurement technologies is greatly reduced. This means the SMU can measure small VF changes such as a 200uV shift in a high-voltage LED.
The SMU digitizer samples continuously, providing single or multiple boxcar-averaged measurements. This approach eliminates the need for external signal processing to obtain a measurement.
Vektrex SMU In The News
Measurement Repeatability
LM-85 Light Measurements for High Power LEDs
Source Measure Unit
Accurate Optical Measurements of Light Emitting Diodes and Laser Diodes
Source Measure Unit
UV LED Thyristor Effect
Get Test Flexibility With Force Sense Selector Switch
The SpikeSafe SMU Force Sense Selector Switch supplies integrated Connect/Disconnect and A/B Switch functions.
Critical for high-speed production environments, the connect/disconnect function is a true isolated switch that rapidly disconnects power to test devices, eliminating control steps and speeding testing.
A/B Switch functions allow secondary instruments to share load wiring with the SMU. Secondary instruments may provide low current and reverse voltage measurements. With many secondary instruments available and currently in use, the A/B switch function enables these instruments to be used in parallel with Vektrex SMU. For example, use Vektrex SMU for higher currents, higher output power, faster pulsing, and better measurements. Use secondary instruments for reverse voltage and very low currents.
Easy-to-Use Control Panel Software Application
Vektrex’s easy-to-use Control Panel Software Application provides turn-key control of the SMU along with external source-measure units, high-speed sampling voltmeters and spectrometers. Control Panel’s intuitive test tools and graphic displays support common optoelectronic tests such as LI sweeps, slope efficiency testing and junction temperature measurement.



