Unitrode Corporation

Linear Technology Corporation

John P Bazinet

John A O'Connor

David Charles Salerno

John H Ziegler

Dhaval B Dalal

Apparatus and method for a polarity independent step-up converter capable of operating with ultra low input voltage. The step-up converter as disclosed herein receives an input source having a variable polarity and includes a first core circuit coupled to the input source and an output of the step-up converter and a second core circuit coupled to the input source and the output of the step-up converter. The first core circuit is configured to be active for a first input voltage polarity to output a first step-up voltage and the second core circuit is configured to be active for a second input voltage polarity to output a second step-up voltage.

Method and system for polarity independent step-up converter capable of operating under ultra-low input voltage condition

Novel system for supplying power from multiple power sources to a powered device has first and second input power supplies for respectively providing power from first and second power sources. An input selector circuit is responsive to the first and second input power supplies for producing an input power supply signal provided to a power regulator, such as a DC-DC converter, for generating a regulated output power supply signal. The power regulator includes a first transistor device controlled to support conversion of the input power supply signal into the output power supply signal if the input power supply signal is provided by the first input power supply, and a second transistor device controlled to support conversion of the input power supply signal into the output power supply signal if the input power supply signal is provided by the second input power supply.

Dual-input DC-DC converter with integrated ideal diode function

A power factor correction controller is disclosed which extracts RMS information from a rectified AC input line voltage signal using a sample and hold analog to digital conversion approach. The controller then processes a digital word representing the RMS information through the application of a programmable mathematical function. The result is converted to analog form and provided as an input to an analog multiplier. The controller also monitors the output load power of an isolated boost converter circuit and linearly reduces the overlap delay time of a MOSFET transition switch when the load power decreases.

Controller for isolated boost converter with improved detection of RMS

An integrated circuit controller for a switching power converter implementing feed-forward and synchronization features. The controller IC has pins which permit dual functionality. The feed-forward feature is implemented with a supply voltage from an unregulated auxiliary winding which additionally powers the controller. The synchronization feature is implemented by coupling an external synchronization signal to a feedback pin of the controller IC to which a feedback signal from the output of the converter is also coupled.

Controller having feed-forward and synchronization features

A synchronous step-down DC to DC converter includes a bootstrap capacitor monitored by a controller for maintaining a desired bootstrap voltage to drive a high side NMOS switch. The controller temporarily increases the duty cycle of the low side NMOS switch when the bootstrap voltage decreases below a predetermined level to maintain a minimum level of charge on the bootstrap capacitor.

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Concord, NH, United States of America

John P Bazinet