20A High Current Source Measure Unit

• Fast, accurate pulses keep DUT junction temperature rise low, enhancing light measurement accuracy
• Hardware timing/triggering improves measurement repeatability
• Integrated true-differential digitizer supports sub-millivolt Vf measurements to 400V
• Optional BIAS source supports JEDEC junction temperature measurements
• Automatically project Vf(0) or generate IV plots using Vektrex Control Panel software Software

The 20A SpikeSafe Source Measure Unit supplies precision DC, continuous pulse, and single pulse current with excellent pulse fidelity. Output pulses have fast rise and fall times – key to precise and repeatable LED, LIDAR, and VCSEL photometric and electrical measurements. A precision hardware-controlled timing system supports pulse widths from 1µs to 15000s. Continuous power conversion means no duty cycle or pulse width limitations.

In addition to robust current capability, the SpikeSafe SMU features a low noise, true differential digitizer optimized for component testing.

The SpikeSafe SMUs (Source Measure Units) are designed with versatile operational modes to cater to a wide range of applications. These general operational modes include:

• DC Mode: Provides continuous direct current for applications that require a steady and stable current supply.
• Continuous Pulse Mode: Allows for pulsed current with adjustable parameters for various testing scenarios.
• Single Pulse Mode: Enables the delivery of a single, precise pulse, ideal for specific testing conditions.

Additionally, SpikeSafe SMUs come with specialized operational modes that are hardware-integrated for user convenience:

• Sweep Mode: Allows for sweeping current or voltage across a range to analyze device characteristics.
• Burst Mode: Facilitates the generation of multiple pulses in quick succession.
• Repetitive Burst Mode: Provides repeated bursts of pulses for extended testing and analysis.

This digitizer can sample device Vf at 500ksps and pick up millivolt changes in voltage that occur during pulsed operation. This sensitivity supports the most accurate IES LM-85 and CIE 225 measurements. Other instruments, that rely on single-ended circuitry, suffer from high common mode noise, making accurate measurements difficult or impossible.

The SpikeSafe SMU easily measures a 4mV Vf shift associated with 0.2C of device heating in a high-power COB LED. A digitizing DMM has far too much common mode noise to see the trend.

An optional A/B switch allows load wiring to be automatically routed to an external parametric measurement unit such as a femtoamp source/measure device.

Devices being tested are protected with SpikeSafe load protection during operation. SpikeSafe load protection continuously monitors voltage and current patterns and instantly shuts down the drive current when device anomalies are detected.

The notable specifications for this current source are as follows: the low range output current accuracy is 0.04%+700µA. The high range output current accuracy is 0.08%+4mA. The pulse width range is 1µs-15000s and the pulse width accuracy is 1.3µs. The pulse rise/fall time is 350ns-4.5ns and typical pulse width jitter is 30ns. This model offers 500W total output power using an internal power supply and the option to add an auxiliary power supply.