Flextronics Ap, LLC

Astec International Limited

Peter Ramos Yeo

Mark D Telefus

Bahman Sharifipour

Aldimarl Mantilla Navarro

Gordon Currie

Anthony Hernandez

Cesar Calma

Fidel Vista

A cascade power system includes a non-isolated buck converter in cascade with an isolated Class-E resonant circuit, where the Class-E resonant circuit operates at high frequency, for example 4 Mhz. Further, the non-isolated buck converter is configured as a current source coupled to the Class-E resonant circuit which provides a buck converter output voltage as input to the Class-E resonant circuit. The Class-E resonant circuit includes capacitive isolation for the cascade power system output.

Cascade power system with isolated Class-E resonant circuit

A cascade power system includes a non-isolated buck converter in cascade with an isolated Class-E resonant circuit, where the Class-E resonant circuit operates at high frequency, for example 4 Mhz. Further, the non-isolated buck converter is configured as a current source coupled to the Class-E resonant circuit which provides a buck converter output voltage as input to the Class-E resonant circuit. The Class-E resonant circuit includes capacitive isolation for the cascade power system output. The Class-E resonant circuit and the capacitive isolation are configured such that impedance matching for the resonant tank of the Class-E resonant circuit is independent of an output load condition.

Current controlled resonant tank circuit

A power converter includes a self-driven circuit for appropriately turning ON and OFF a synchronous rectifier during the operating cycle of the power converter. Without the use of a smart controller coupled to the synchronous rectifier, the self-driven circuit turns ON the synchronous rectifier during the positive cycle of the power converter when the main switch is turned OFF, and the self-driven circuit turns OFF the synchronous rectifier during the negative cycle of the power converter when the main switch is turned ON. Unlike conventional self-driven circuits that include an auxiliary secondary winding for driving a synchronous rectifier, the self-driving circuitry of the present application does not include an auxiliary secondary winding.

Self-driven synchronous rectifier circuit

A cascade power system includes a non-isolated buck converter in cascade with an isolated Class-E resonant circuit, where the Class-E resonant circuit operates at high frequency, for example 4 Mhz. Further, the non-isolated buck converter is configured as a current source coupled to the Class-E resonant circuit which provides a buck converter output voltage as input to the Class-E resonant circuit. The Class-E resonant circuit includes capacitive isolation for the cascade power system output. The cascade power system further includes a feedback control circuit for regulating a system output voltage. A feedback signal is used to adjust a duty cycle of the buck converter, thereby adjusting a buck converter output voltage. The buck converter output voltage is provided as input to the Class-E resonant circuit.

An enclosure for small power supplies for cellular telephones, laptop computers and the like is formed in two layers. The first layer is an inner box constructed of a pair of about 0.8 mm thick PBT shells that enclose and retain the electronics. The second layer is an overmolding of about 1.0 mm. thick PVC that surrounds the shells, seals them together, and forms a strain relief for a cable attached to the electronics. The two-layer construction allows considerable savings in material and assembly costs.

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Quezon, Philippines

Peter Ramos Yeo