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.
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.
20A Source Pulse Shapes
Precision pulsing is key to best practices measurements. The 20A Source Measure Unit offers programmable pulse width flexibility. It is capable of long pulse widths (ms to seconds) and short pulse widths (100us pulse widths and faster). With the pulse source, minimum 10us pulse widths are available with upgrades for fast precision pulsing (1us pulse widths). Pulse width accuracy is 1.3us with nanosecond pulse rise and fall times. Ramp time is adjustable. Fast transient response saves devices.