Patent · US Expired

Clamp circuit and method for identifying a safe operating area

US5581432A · kind A · utility

14Cited by
7References
15Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJul 25, 1995
Grant dateDec 3, 1996
Priority date
Expiry dateJul 25, 2015

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH03K17/0822
  • WIPO fieldBasic communication processes
  • WIPO sectorElectrical engineering

Abstract

A clamp circuit (10) for protecting a MOSFET (12) from destructive voltages and currents includes a clamping element (30), a current switch (27), a bond pad (23), a probe pad (25), and a resistor (21). When no external signal is applied to the probe pad (25), a FET (18) in the clamping element (30) is conductive. When the drain voltage of the MOSFET (12) rises above a clamping voltage of the clamping element (30), a current flows through the clamping element (30) and switches on the MOSFET (12). To ensure a safe operating area of the MOSFET (12), a voltage is applied to the probe pad (25) to turn off the FET (18), a breakdown voltage of the MOSFET (12) measured from the bond pad (23) is compared with the clamp voltage, and circuit die with the breakdown voltage less than the clamp voltage are discarded.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.