40A High Current Source Measure Unit

• Fast, accurate pulses keep device cooler with more uniform heating
• Hardware timing/triggering essential for measurement repeatability
• Get sub-millivolt Vf measurements from integrated true-differential digitizer
• Optional BIAS source for thermal resistance and junction temperature measurements
• Hardware integrated pulsed sweep capability

The 40A SpikeSafe Source Measure Unit is a High Current Source Measure Unit. Output pulses have nanosecond rise and fall times – key to precise and repeatable LED, LIDAR, VCSEL photometric and electrical measurements. This SMU supplies precision DC, continuous pulse, and single pulse current with excellent pulse fidelity. A precision hardware-controlled timing system ensures measurement repeatability with synchronization of source, measure and external instrumentation. Continuous power conversion means no duty cycle or pulse width limitations.

The SpikeSafe High Current SMU features a low noise, true differential digitizer optimized for component testing. 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.

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.

Devices being tested are protected with a gentle turn-on during ramp-up and 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 0.4%+1.4mA. The high range output current accuracy is 0.08%+8mA. The pulse width range is 10µs-15000s and the pulse width accuracy is 1.3µs. The pulse rise/fall time is 350ns-4.5µs and the typical pulse width jitter is 30ns.