Over temperature protection with soft shutdown for power amplifier

Abstract

Various methods and circuital arrangements for protection of a power amplifier from over temperature are presented. According to one aspect, a protection circuit coupled to a temperature sensor controls a biasing current or voltage to the power amplifier to limit a power dissipation through, and therefore a temperature of, the power amplifier when a high limit temperature is sensed. When the high limit temperature is sensed, the biasing current or voltage decreases as a linear function of the sensed temperature while allowing the power amplifier to operate. A slope of the linear function and a value of the high limit temperature can be made programmable. Programmability of the slope and the high limit temperature can be used to control biasing currents or voltages to a plurality of power amplifiers operating at different times and having different thermal requirements.

Dependencies are inferred from the claim text.