Two terminal drive of bipolar junction transistor (bjt) for switch-mode operation of a light emitting diode (led)-based bulb

An apparatus, comprising:

• a controller configured to couple to a base and to an emitter of a bipolar junction transistor (BJT),
• wherein the controller is configured to perform the steps comprising:
• driving a base current from a base current source to the base of the bipolar junction transistor (BJT) to maintain conduction of the bipolar junction transistor (BJT) during a first time period;
• disconnecting the base current source from the bipolar junction transistor (BJT) for a second time period;
• repeating the steps of driving the base current during the first time period and disconnecting the base current source for the second time period to obtain an average current output to a load;
• and
• dynamically adjusting the base current output from the base current source to adjust a reverse recovery time period of the bipolar junction transistor (BJT).

An integrated circuit (IC), comprising:

• a base current source configured to be coupled to the base of the bipolar junction transistor (BJT) through a first base switch;
• and
• a controller coupled to the base current source and configured to couple to an emitter switch coupled to an emitter of the bipolar junction transistor (BJT),
• wherein the controller is configured to perform the steps comprising:
• driving a base current from the base current source to the base of the bipolar junction transistor (BJT) to maintain conduction of the bipolar junction transistor (BJT) during a first time period;
• disconnecting the base current source from the bipolar junction transistor (BJT) for a second time period;
• repeating the steps of driving the base current during the first time period and disconnecting the base current source for the second time period to obtain an average current output to a load;
• and
• dynamically adjusting the base current output from the base current source to adjust a reverse recovery time period of the bipolar junction transistor (BJT), wherein at least a portion of the base current output is proportional to a collector current of the bipolar junction transistor (BJT).