Linear Technology Corporation

Analog Devices International Unlimited Company

Linear Technology Holding LLC

Trevor Wayne Barcelo

David McLean Dwelley

Robert Loren Reay

Jeffrey Lynn Heath

Samuel Hodson Nork

Steven Leo Martin

Roger A Zemke

David B Bell

Jonathan Wayde Celani

Brian James Shaffer

David Justin Simmons

David F Schneider

An ideal diode circuit is described which uses an NMOS transistor as a low-loss ideal diode. The control circuit for the transistor is referenced to the anode voltage and not to ground, so the control circuitry may be low voltage circuitry, even if the input voltage is very high, referenced to earth ground. A capacitor is clamped to about 10-20 V, referenced to the anode voltage. The clamped voltage powers a differential amplifier for the detecting if the anode voltage is greater than the cathode voltage. The capacitor is charged to the clamped voltage during normal operation of the ideal diode by controlling the conductivity of a second transistor coupled between the cathode and the capacitor, enabling the circuit to be used with a wide range of frequencies and voltages. All voltages applied to the differential amplifier are equal to or less than the clamped voltage.

Self-biasing ideal diode circuit

A current monitor circuit comprises a sense transistor disposed in a first voltage domain; a reference transistor disposed in a second voltage domain isolated from the first voltage domain; and sensing circuitry configured to determine if a current in the sense transistor is greater than or less than a specified current using a current in the reference transistor.

High precision switched capacitor MOSFET current measurement technique

An ideal diode circuit is described which uses an NMOS transistor as a low-loss ideal diode. The control circuit for the transistor is referenced to the anode voltage and not to ground, so the control circuitry may be low voltage circuitry, even if the input voltage is very high, referenced to earth ground. A capacitor is clamped to about 10-20V, referenced to the anode voltage. The clamped voltage powers a differential amplifier for the detecting if the anode voltage is greater than the cathode voltage. The capacitor is charged to the clamped voltage during normal operation of the ideal diode by controlling the conductivity of a second transistor coupled between the cathode and the capacitor, enabling the circuit to be used with a wide range of frequencies and voltages. All voltages applied to the differential amplifier are equal to or less than the clamped voltage.

A composite transconductance amplifier is formed using a single transconductance amplifier with its output connected to a load via one or more resistors in series. The single transconductance amplifier has a linear transconductance (gm). As the current through the series resistors is increased, the voltage drops across the nodes of the resistors increase. Control terminals of separate drive circuits are connected to the various nodes and successively turn on as the current from the single transconductance amplifier slews more positive. Thus, the effective gm of the composite transconductance amplifier is based on the gm of the single transconductance amplifier and the currents contributed by the successively enabled drive circuits. Therefore, the gm is nonlinear. Pull-down drive circuits are also connected to the resistor nodes to successively pull down the current as the output from the single transconductance amplifier slews negative. The composite transconductance amplifier has low quiescent current.

Transconductance amplifier with nonlinear transconductance and low quiescent current

An apparatus and method for charging a battery includes a battery to be charged, a power delivery path configured for delivering power to the battery, and an integrated switching battery charger configured for charging a battery by delivering output power to the battery via the power delivery path based on input power from an input power source. The integrated switching battery charger includes an output voltage regulation loop and an input voltage regulation loop, both of which are configured to control the output current flowing out of the integrated switching battery charger to the battery. The input or output voltage regulation loops are further enhanced by adding a current source which is proportional to absolute temperature from the regulated voltage to the control voltage for the purpose of either regulating peak power from the source or to maximize energy storage in the battery as a function of temperature.

Method and system for solar panel peak-power transfer using input voltage regulation

A switching circuit coupled to one or more input sources and having one or more switching elements controlled to produce an output for charging a battery. A first control circuit is responsive to current of the switching circuit for producing a first control signal to drive the switching element so as to control the current. A second control circuit is responsive to voltage at the battery for producing a second control signal to drive the switching element so as to control voltage developed across the battery. A selector circuit is responsive to the first and second control signals for selectively controlling the switching element.

Switching battery charger with programmable current control and power control

Current control circuitry for controlling current supplied from a source, that may be a current-constrained source, to a load and a battery. A current limit control circuit limits current supplied by the source to the load in accord with a programmed current limit. Load current is measured, and an input charger control circuit controls magnitude of current to the battery based on the difference between measured load current and battery current programmed to be supplied to the battery, such that the sum of load current and battery current is maintained within the programmed current limit.

Current control circuitry and methodology for controlling current from current constrained source

A power manager is configured to manage power for a battery-powered application. A power source, a load and a battery are interconnected through a circuit path. Power from the power source is provided to the load and battery by a switching regulator. Various implementations are presented.

Power manager and power managing method for battery-powered application

Methods and circuits implementing a constant-current/constant-voltage circuit architecture are provided. The methods and circuits preferably provide a charging system that provides current to a load using a fixed current until the load is charged. When the load is charged, the methods and circuits preferably provide a variable current to the load in order to maintain the voltage level across the load. This variable current varies according to the voltage across the load. In one embodiment of the invention, a constant power current may also be used as one of the load charging currents. The constant power current may act as a limit on the charging circuit's power output.

Constant-current/constant-voltage circuit architecture

Constant-current/constant-voltage current supply

A linear pulse-width modulator system is provided. The pulse-width modulation system of the present invention provides a pulse-width modulated (PWM) signal from a control voltage. The PWM signal varies linearly with the control voltage over a full range of duty cycles. The pulse width modulation system of the present invention has as plurality of comparators, each having one input coupled to a control voltage and a second input coupled to a periodic waveform signal provide by a waveform generator. The periodic waveform signals are identical except that each waveform is time delayed with respect to the other waveform signals. The outputs the comparators are coupled to a multiplexer which selects the output of each comparator as the PWM signal for a time interval corresponding to when the output signal of the comparator has substantially constant propagation delays. The propagation delays in the a comparator's output signal are substantially constant when the periodic waveform signal input of the comparator is not near the its minimum or maximum voltage.

Systems and methods for linearly varying a pulse-width modulation signal with a control signal

A high efficiency control circuit for operating a buck-boost switching regulator is provided. The switching regulator can regulate an output voltage higher, lower, or the same as the input voltage. The switching regulator may be synchronous or non-synchronous. The control circuit can operate the switching regulator in buck mode, boost mode, or buck-boost mode. In buck mode, the switching regulator regulates an output voltage that is less than the input voltage. In boost mode, the switching regulator regulates an output voltage that is greater than the input voltage. In buck and boost modes, less than all of the switches are switched ON and OFF to regulate the output voltage to conserve power. In buck-boost mode, all of the switches switch ON and OFF to regulate the output voltage to a value that is greater than, less than, or equal to the input voltage.

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Andover, MA, United States of America

Trevor Wayne Barcelo