MOSFET Thermal Tests on FTI-1000

DVSD is the difference of two VSD (body diode voltage drop) measurements done before and after heating up the device for a certain period (heating time).

How Test is Done:

With device at off state, a small current is forced across the body diode and the voltage drop is measured (VSD1).  Then device is turned on and heated up for a specified amount of time. A voltage is applied in the Drain to force a defined large current across the Drain-Source terminals at a specified period of time. After the device heating event, the device is switched back off and the same small current (as the initial forced value) is forced through the body diode and the voltage drop is again measured (VSD2). A good device performance will give a very minimal voltage difference measurement between VSD1 and VSD2.

DVSD = VSD1 – VSD2

Test Method Diagram

VSD Measurement

Delta VSD Test Diagram

Heating Event

Delta VSD Test Method Diagram

Timing Chart for DVSD Test for MOSFETs

Delta VSD Timing Chart