Abstract: Electronic module with all-sided electromagnetic interference (EMI) shielding and methods of making same. The electronic module includes an encapsulated circuit board between a top plate and a conductive bottom plate, electrical leads extending from the circuit board through the bottom plate, and a continuous conductive coating substantially covering the entire electronic module except for a bottom surface of the bottom plate. The conductive coating forms direct, independent connections at least to the circuit board and the bottom plate. The conductive coating provides EMI shielding across the top and sides of the electronic module. The conductive bottom plate provides EMI shielding across the bottom of the electronic module. Methods of manufacturing include encapsulating a circuit board between a top plate and bottom plate, separating materials from the encapsulated circuit board to expose conductive traces on the circuit board and bottom plate, and coating the sawed device with a conductive coating.

Abstract: A switched mode power supply is provided comprising a pulse-width-modulator (PWM), a power section, and a drive section for the power switch. The drive section consists of a new method of driving the power switch where it is desired that the switch terminals be isolated from the PWM ground. The new driver design, which incorporates a small isolation transformer along with unique modifications to the traditional DC restore circuit, is directed to solving problems when PWM type switching power supplies encounter fault conditions such as a short circuit across their output as well as protecting the switch and the load when an ordinary shutdown or disable command is received. One problem that arises with switch drivers that utilize isolation transformers during an overload event or even an ordinary shutdown event is that the driver does not turn off and hold off the power switch when it is commanded to do so.

Abstract: A power converter using a switching signal having at least three levels of amplitude, one of which amplitude levels has a zero amplitude level during a predetermined switching interval, is provided. The power converter includes a circuit module having first and second input terminals for receiving the switching signal. The circuit module in turn is made up of a first power transistor and second power transistor. Circuitry is electrically coupled to a predetermined one of the power transistors for maintaining a predetermined voltage level across the gate terminal of the predetermined one of the power transistors during the switching interval of zero amplitude. The predetermined voltage level is chosen to enable that predetermined power transistor to continue in a respective "on" state notwithstanding of the presence of the switching interval of substantially zero amplitude.

Abstract: A method and apparatus for maintaining relatively low ripple current in a dc-dc converter while minimizing the size of an inductive line filter utilizes a transformer having at least a pair of secondary windings in which the secondary windings are selected to have different numbers of winding turns depending on the specific design of the ideal duty factor at which the converter will be operated. In addition, the converter is provided with an active pre-load which establishes a continuous conduction current when load current is below some selected minimum value in order to provide control stability during light load conditions without converter oscillations.