Forward Biased SOA Measurements

DESIGN PHASE:       measurement
SUB ELEMENT NAME:   photo measurement -
                    forward biased safe operating area measurement
VARIABLE NAME:      [HEMTFSOA]
DATE:               REVISION LETTER:    REVISION DATE:
APPLICABILITY:      series regulator

ACTIVITY:  Measure (take oscilloscope photograph) of series pass
transistor current vs voltage during turn on or other worse case
condition for forward biased secondary breakdown.

OUTPUT:  Labeled photograph in laboratory notebook for comparison
to transistor FBSOA specification and circuit analysis (usually
Spice plots under same conditions).

ALGORITHM:

[HEMTFSOA] =   engineer hours for measuring forward biased safe
               operating area
[HTMTFSOA] =   technician hours for measuring forward biased safe
               operating area
0.0            time to make measurement

DISCUSSION:

Author: Jerrold Foutz, foutz@smpstech.com

Original: Foutz, J., Power Supply Circuit Development Estimating Aid - An Expert System Application, IEEE Applied Power Electronics Conference Record, New Orleans, February 1-5, 1988. Revised 25 February 2001