Intersil Americas Inc.

Paul K Sferrazza

Noel B Dequina

Donald R Preslar

Robert H Isham

Eric Magne Solie

Chun Cheung

Mehul Dilip Shah

William Brandes Shearon

Stanley F Wietecha

Emil Chen

Weihong Qui

Bin Li

A method to soft start a charge pump circuit according to embodiments includes enabling switching for a plurality of power transistors, selecting a first switching control signal from a plurality of switching control signals for the selected plurality of power transistors, slowly ramping up a plurality of bootstrap supply voltages associated with the selected plurality of power transistors, driving a gate-to-source voltage of each power transistor of the selected plurality of power transistors at a first predefined level, and determining if the plurality of bootstrap supply voltages are less than a second predefined level. If the plurality of bootstrap supply voltages are less than the second predefined level, the method further includes toggling and thereby selecting a second switching control signal from the plurality of switching control signals for a second selected plurality of power transistors.

Method and circuitry to soft start high power charge pumps

A phase doubler driver circuit includes first control logic generates a first output PWM drive signal and a second output PWM drive signal responsive to an input PWM drive signal. In a first mode of operation, alternating pulses of the input PWM drive are output as the first output PWM drive signal and the second PWM output drive signal respectively. In a second mode of operation, the input PWM drive signal is provided as the first output PWM drive signal when a second phase current associated with the second output PWM drive signal exceeds a first phase current associated with the first output PWM drive signal and the input PWM drive signal is provided as the second output PWM drive signal when the phase current associated with the first output PWM signal exceed the phase current associated with the second output PWM signal. Second control logic adds an offset to a falling edge of the first output PWM drive signal responsive to a difference between a first current associated with the first phase current and an average current and for adding the offset to a falling edge of the second output PWM signal responsive to a difference between a second current associated with the second phase current.

Phase doubler

An over-voltage protection circuit prevents an anomaly, such as a short circuit in the upper-switched electronic device of a DC-DC power supply, from propagating to downstream circuitry. The over-voltage protection circuit, which includes an overvoltage sense resistor coupled between an output of the upper or high side FET and the gate of the lower FET, is operative to sense a short circuit fault condition in the circuit path through the upper FET during initial power up of the system. In response to this condition, the lower NFET device is turned on so as to provide an immediate by-pass of the overvoltage condition to ground, and thereby prevent excessive voltage from being applied by the output terminal to downstream powered circuitry.

Mechanism for providing over-voltage protection during power up of DC-DC converter

A multi-level current pulse generator for driving the gates of a CMOS pair implemented using a low voltage process including a multi-level pulse translator, a current amplifier circuit, and a clamp circuit. The multi-level pulse translator generates a multi-level current pulse on at least one pulse node, each current pulse having a first large current pulse with short duration followed by at least one smaller current pulse of longer duration and operative to switch the CMOS pair with reduced average power dissipation. The current amplifier circuit amplifies the current pulses provided to the gates of the CMOS pair. The clamp circuit clamps gate voltage of the CMOS pair to prevent breakdown. In a tri-level case, a first current pulse charges and discharges gate capacitance, a second current pulse stabilizes gate voltage, and a third current pulse provides a holding current level.

High voltage gate driver using a low voltage multi-level current pulse translator

A body diode comparator circuit for a synchronous rectified FET driver including a sample circuit and a comparator. The FET driver has a phase node coupled between a pair of upper and lower switching FETs and is responsive to a PWM signal having first and second phases for each cycle. The sample circuit samples an initial voltage of the phase node during the first phase of the PWM signal and provides a sum voltage indicative of the initial phase voltage added to the voltage level of the phase node during the second phase of the PWM signal. The comparator compares the sum voltage with a predetermined reference voltage and provides an output indicative of an activation state of the lower FET during the second phase of the PWM signal. The FET driver turns on the upper FET when the comparator indicates that the lower FET is off.

System and method of detecting phase body diode using a comparator in a synchronous rectified FET driver

A cascaded DC-DC converter architecture has an upstream converter stage and a downstream converter stage, which derives its input voltage from the upstream stage. Cascading the two converter stages enables functionality of control and monitoring (including soft start and overcurrent detection) circuitry of the upstream stage to be used for the downstream stage, to reduce chip area, cost, and complexity. A voltage window regulator in the downstream converter ensures that, during shutdown, its output voltage will be maintained within a prescribed window of its regulated output voltage, so that no soft start delay is needed when the second converter stage is turned back on.

Integrated circuit for generating a plurality of direct current (DC) output voltages

The problem of charge leakage in the AC compensation filter for the error amplifier of a pulse width modulation (PWM)-based DC&#x2014;DC converter is effectively obviated by controllably sampling and storing the voltage across the AC compensation filter, in response to a transition of the operation of a DC power supply from run or active mode to quiescent or sleep mode. The sampled voltage is retained as a compensation voltage throughout the quiescent mode, so that it will be immediately available to the PWM circuitry at the termination of the quiescent interval. This serves to ensure a relatively smooth (low noise) power supply switch-over during a subsequent transition from quiescent to active mode.

Compensation sample and hold for voltage regulator amplifier

A control circuit for a switch mode DC-DC converter contains an arrangement of monitored LGATE, UGATE and PHASE node condition threshold detectors, outputs of which are processed in accordance with a switching control operator to ensure that each of an upper FET (UFET) and a lower FET (LFET) is completely turned off before the other FET begins conduction, thereby maintaining a dead time that exhibits no shoot-through current and is independent of the type of switching FET.

PWM-based DC-DC converter with assured dead time control exhibiting no shoot-through current and independent of type of FET used

An over-voltage protection circuit prevents an anomaly, such as a short circuit in the upper-switched electronic device of a DC&#x2014;DC power supply, from propagating to downstream circuitry. The over-voltage protection circuit, which includes an overvoltage sense resistor coupled between an output of the upper or high side FET and the gate of the lower FET, is operative to sense a short circuit fault condition in the circuit path through the upper FET during initial power up of the system. In response to this condition, the lower NFET device is turned on so as to provide an immediate by-pass of the overvoltage condition to ground, and thereby prevent excessive voltage from being applied by the output terminal to downstream powered circuitry.

A programmably switched, multi-output stage current mirror-based, current-sensing and correction circuit controls the operation of a buck mode DC&mdash;DC converter. This correction circuit generates a correction current having a prescribed step-wise temperature-compensating relationship to sensed current. The sensed current is derived from a variable impedance controlled by a sense amplifier coupled via a current feedback resistor to the common output node between a high side power switching device and a low side power switching device of the converter. To program the correction circuit a decoder maps temperature information associated with the low side power switching device and additional programming information into a current mirror control code.

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New Hope, PA, United States of America

Paul K Sferrazza