Power detector with overdrive detection

摘要

Aspects of this disclosure relate to protecting a circuit, such as an amplifier, from transient overdrive events and/or average overdrive events. In one embodiment, an indication of average power, such as root mean squared (RMS) power of a radio frequency (RF) signal, can be compared to a first threshold and an indication of a peak RF power can be compared to a second threshold. When the indication of average power exceeds the first threshold, an average overdrive event can be detected. When the indication of peak power exceeds the second threshold, a peak overdrive event can be detected. If either a transient overdrive event or an average overdrive event is detected, a circuit, such as an amplifier, can be protected.

主权项

1. An apparatus comprising:
an envelope detector configured to generate an indication of instantaneous power of a radio frequency (RF) signal; an averaging circuit configured to generate an indication of an average power of the RF signal; a first comparator configured to receive a first threshold and the indication of the average power of the RF signal, and to activate an average overdrive signal based at least partly on comparing the first threshold with the indication of the average power of the RF signal; a second comparator configured to receive a second threshold and the indication of the instantaneous power of the RF signal, and to activate a transient overdrive signal based at least partly on comparing the second threshold with the instantaneous indication of the power of the RF signal; and an alarm circuit configured to generate an overdrive protection signal, wherein the alarm circuit is configured to assert the overdrive protection signal in response to the indication of average power of the RF signal satisfying the first threshold, and wherein the alarm circuit is configured to assert the overdrive protection signal in response to the indication of the instantaneous power of the RF signal satisfying the second threshold.