Qualcomm Incorporated

William Rader

Stuart Pullen

Chunping Song

Hector Ivan Oporta

Zhaohui Zhu

Edward Robert Deak

Certain aspects of the present disclosure generally relate to methods and apparatus for powering up a charge pump converter and providing protection and soft-start circuitry therefor. One example charge pump converter generally includes a first transistor and a second transistor coupled in series between an input voltage node and an output voltage node of the charge pump converter, a first capacitive element having a first terminal coupled to a node between the first and second transistors, and a first switch coupled to the input voltage node, the first switch being configured to selectively enable a first drive circuit having an output coupled to a control terminal of the second transistor.

Power-up sequencing and high voltage protection for charge pump converters

A circuit that stores characterized loss information for a buck converter and uses the characterized loss information instead of measurements involving output power dependent losses. The characterized loss information may include the characterized switching loss, the characterized ripple loss, etc. The circuit may then calculate the output power, efficiency, power dissipation, etc. without needing to measure the output current.

Switching loss correction circuitry and method

In one embodiment, a method receives a shed comparison signal that is based on a comparison of a voltage detected from a voltage converter to a reference voltage and receives a zero cross signal that indicates whether a current from the voltage converter has crossed zero. The shed comparison signal is sampled for a first number of clock cycles to generate shed comparison sampled values. Also, the zero cross signal is sampled for a second number of clock cycles to generate zero cross sampled values where the second number of clock cycles are less than the first number of clock cycles. The method determines a change between a shed state and an unshed state based on the shed comparison sampled values for the first number of clock cycles or the zero cross sampled values for the second number of clock cycles.

Charge shedding circuit

In one embodiment, a correction circuit comprises circuit comprises a replica transistor biased at a current density to match that of a high side transistor of an output power switch at a specific load. A sample and hold circuit is coupled to the replica transistor to sample a voltage across the replica transistor. A differential amplifier provides a level shifted differential replica voltage to a tap of a resistor ladder of a successive approximation register analog-to-digital converter in response to the sampled voltage across the replica transistor. A current source provides a current to a top of the resistor ladder.

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Carrboro, NC, United States of America

William Rader