Protection circuit for power amplifiers

A circuit comprising:

• a plurality of cascaded amplifier stages;
• and
• a protection circuit coupled to a supply voltage node of a first stage of the plurality of cascaded amplifier stages, the first stage operating between the supply voltage node and a reference ground, the protection circuit comprising a current limiter circuit configured to limit a high value of a supply current that flows from the supply voltage node to the reference ground through the first stage, the high value of the supply current based on a magnitude of a reference current;
• wherein the current limiter circuit comprises:
• a reference current source configured to generate the reference current;
• a current mirror comprising an input leg and an output leg, the input leg coupled to the reference current source and the output leg coupled to the supply voltage node;
• and
• a common-source transistor coupled to the input leg of the current mirror, wherein the reference current is a current that flows through the common-source transistor based on a voltage provided to a gate of the common-source transistor.

A circuit comprising:

• a plurality of cascaded amplifier stages;
• and
• a protection circuit coupled to a supply voltage node of a first stage of the plurality of cascaded amplifier stages, the first stage operating between the supply voltage node and a reference ground, the protection circuit comprising a current limiter circuit configured to limit a high value of a supply current that flows from the supply voltage node to the reference ground through the first stage, the high value of the supply current based on a magnitude of a reference current,
• the circuit further comprises additional one or more plurality of cascaded amplifier stages each comprising a respective first stage coupled to the protection circuit,
• at a given time, the circuit processes an RF signal through an activated plurality of cascaded amplifier stages, the activated plurality of cascaded amplifier stages comprising only one of the plurality of cascaded amplifier stages or the additional one or more plurality of cascaded amplifier stages, and
• the protection circuit is further configured to programmatically generate the high value of the supply current based on a specific operating power requirement of the respective first stage of the activated plurality of cascaded amplifier stages.