Patent ID: 7961032

Claim:
Method of recovering gain in a bipolar transistor, comprising: providing a bipolar transistor including an emitter, a collector, and a base disposed between junctions at the emitter and the collector; reverse biasing the junction disposed between the emitter and the base with an operational voltage and for an operational time period, so that a current gain β of the transistor is degraded; idling the transistor, and generating a repair current I br into the base, while forward biasing the junction disposed between the emitter and the base with a first repair voltage (V EBR ), and while at least partly simultaneously reverse biasing the junction disposed between the collector and the base with a second repair voltage (V CBR ), for a repair time period (T R ), so that the gain is at least party recovered; wherein V EBR , V CBR and T R have the proportional relationship: T R ∝(Δβ) 2 ×exp [1/( Tam+Rth×le×V CER ],V CER =V BER +V CBR , and le=β×I br , β is the normal current gain of the transistor, Δβ is the target recovery gain of the transistor in percentage, Tam is the ambient temperature in degrees K, I br is the repair current to the base in μ amps, Rth is the self-heating thermal resistance of the transistor in K/W, T R is in seconds.