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36V transient injector PDF Print E-mail
Thursday, 23 October 2008 21:10

When designing a device for a car, motorcycle or other possibly weird-behaving power source, you might want to try its immunity to power spikes.

The circuit below feeds the DUT with a "normal" DC power (like 13.8V) but also adds square "spikes" from a second (lab) power supply. The AWG (in this case a hp33120a) tells when to add the voltage spikes. The P-channel power MOSFET is controlled by a much smaller N-channel MOSFET (2N7002), forming a level shifter. The Zener is a bit unnecessary in this application but would normally see to that the G-S max voltage (30V) of the power MOSFET is not exceeded.

Transient test circuit

Last Updated on Friday, 24 October 2008 12:07