Abstract: A method of dynamically adjusting a storage time of a bipolar junction transistor (BJT) in a switched mode power converter during a switching cycle includes generating a storage time reference signal responsive to an input voltage signal. A collector off signal is generated responsive to a comparison of a current sense signal to a collector off reference threshold signal. The current sense signal is representative of a switch current of the BJT. A base off reference threshold signal is generated responsive to the storage time reference signal and the collector off signal. A base off signal is generated responsive to a comparison of the current sense signal and the base off reference threshold signal. Charging of a base terminal of the BJT is discontinued responsive to the base off signal, and the base terminal of the BJT is discharged responsive to the collector off signal.

Abstract: A method of dynamically adjusting a storage time of a bipolar junction transistor (BJT) in a switched mode power converter during a switching cycle includes generating a storage time reference signal responsive to an input voltage signal. A collector off signal is generated responsive to a comparison of a current sense signal to a collector off reference threshold signal. The current sense signal is representative of a switch current of the BJT. A base off reference threshold signal is generated responsive to the storage time reference signal and the collector off signal. A base off signal is generated responsive to a comparison of the current sense signal and the base off reference threshold signal. Charging of a base terminal of the BJT is discontinued responsive to the base off signal, and the base terminal of the BJT is discharged responsive to the collector off signal.

Abstract: A controller for a power converter includes a driver circuit that generates a control signal to switch a power switch in response to an output, and a control circuit that controls the switching of the power switch. The control circuit includes a storage time reference circuit generates a storage time reference signal responsive to an input. A first comparator generates a collector off signal in response to a comparison of a switch current sense signal and a collector off reference signal. A storage time regulator circuit generates a base off reference signal in response to the storage time reference signal and the collector off signal. A second comparator generates a base off signal in response to a second comparison of the switch current sense signal and the base off reference signal. The driver circuit is coupled to discontinue and start charging a base terminal of the BJT power switch.

Abstract: A power converter includes a transformer coupled to transfer power from a primary side of the power converter to a secondary side of the power converter. The transformer includes a primary side winding coupled to receive power from a primary side input of the power converter and a secondary side winding coupled to provide power to a secondary side output of the power converter. A power switch is coupled to the transformer, and a power switch controller is coupled to control the switching of the power switch between an ON state and an OFF state. A communication circuit is coupled to communicate data between the primary side of the power converter and the secondary side of the power converter.

Abstract: A controller for a power converter includes a driver circuit that generates a control signal to switch a power switch in response to an output, and a control circuit that controls the switching of the power switch. The control circuit includes a storage time reference circuit generates a storage time reference signal responsive to an input. A first comparator generates a collector off signal in response to a comparison of a switch current sense signal and a collector off reference signal. A storage time regulator circuit generates a base off reference signal in response to the storage time reference signal and the collector off signal. A second comparator generates a base off signal in response to a second comparison of the switch current sense signal and the base off reference signal. The driver circuit is coupled to discontinue and start charging a base terminal of the BJT power switch.

Abstract: A power converter controller includes a storage time reference circuit to generate a storage time reference signal in response to an input voltage signal. A first comparator generates a collector off signal in response to a current sense signal of a BJT and a collector off reference threshold signal. A storage time regulator circuit generates a base off reference threshold signal in response to the storage time reference signal and the collector off signal. A second comparator generates a base off signal in response to the current sense signal and a base off reference threshold signal. A driver circuit controls switching of the BJT in response to an output voltage signal, discontinues charging a base terminal of the BJT in response to the base off signal, and starts discharging the base terminal of the BJT in response to the collector off signal during a switching cycle of the BJT.

Abstract: A power converter controller includes a storage time reference circuit to generate a storage time reference signal in response to an input voltage signal. A first comparator generates a collector off signal in response to a current sense signal of a BJT and a collector off reference threshold signal. A storage time regulator circuit generates a base off reference threshold signal in response to the storage time reference signal and the collector off signal. A second comparator generates a base off signal in response to the current sense signal and a base off reference threshold signal. A driver circuit controls switching of the BJT in response to an output voltage signal, discontinues charging a base terminal of the BJT in response to the base off signal, and starts discharging the base terminal of the BJT in response to the collector off signal during a switching cycle of the BJT.

Abstract: A switched mode power converter (SMPC) has an isolation transformer for power transfer and a communication circuit for data communication between the primary side and the secondary side. The SMPC includes a primary switch controller configured to transfer power from a primary side to a secondary side by controlling a primary switch ON for an ON time period and then controlling the primary switch OFF for an OFF time period. The primary switch controller controls the ON time period of the subsequent power transfer cycle to start a time delay after the end of the OFF time period of the previous power transfer cycle. The communication circuit comprises a magnetically coupled transmission winding and reception winding, a communication switch, and a communication controller to control the communication switch to allow charge flow through the transmission winding during at least part of the time delay for data communication.