Linear Technology Corporation

Analog Devices International Unlimited Company

Other

Gregory Jon Manlove

Robert Chiacchia

Jian Li

Kalin Valeriev Lazarov

Andrew J Gardner

Yi Ding Gu

Michael David Petersen

Edson Wayne Porter

Hengsheng Liu

Yiding (Eric) Gu

Hellmuth Stephen Witte

James McKenzie

Andrew Joseph Gardner

Robert C Chiacchia

A system current sensor module can accurately sense or measure system current flowing through a sense current resistor by shunting current through a gain-setting resistor and using an amplifier to measure a resulting voltage, with an output transistor controlled by the amplifier controlling current through the gain setting resistor in a manner that tends to keep the amplifier inputs at the same voltage. The resistors can be thermally coupled to maintain similar temperatures when a system current is flowing. The thermal coupling can include conducting heat from a first resistor layer carrying the current sense resistor to a thermal cage layer located beyond a second resistor layer carrying the gain-setting resistor. This preserves accuracy, including during aging.

Low temperature coefficient current sensor

A current mode switching regulator circuit and operating method includes a variable duty cycle power switch controller, a voltage feedback loop that provides a feedback signal based on the output voltage, a current feedback loop that provides a current sense signal based on the output current, and an offset circuit having an external signal input and coupled to the current feedback loop. The power switch controller controls the switching regulator circuit to generate an output voltage and an output current. The offset circuit is configured to provide an offset output control signal, independently of the voltage feedback loop, to control the power switch controller so as to vary a duty cycle of the power switch controller based on the current sense signal and an external offset signal applied to the external signal input.

Current mode switching regulator and operating method with offset circuitry to emulate a transient load step response

A switching regulator circuit incorporates an offset circuit, connected in a control loop of the regulator circuit, that, in response to a signal indicating an imminent load current step, adjusts a duty cycle of a power switch for the current step prior to the regulator circuit responding to a change in output voltage due to the current step. In one embodiment, a load controller issues a digital signal shortly before a load current step. The digital signal is decoded and converted to an analog offset signal in a feedback control loop of the regulator to immediately adjust a duty cycle of the switch irrespective of the output voltage level. By proper timing of the offset, output voltage ripple is greatly reduced. The current offset may also be used to rapidly change the output voltage in response to an external signal requesting a voltage step.

Feed forward current mode switching regulator with improved transient response

A switching regulator is configured to provide a regulated voltage to a load while maintaining a substantially maximum output current limit, the switching regulator having a loop gain. In accordance with one aspect the switching regulator comprises: a circuit for adjusting the maximum output current limit in response to a programmable signal independently of the loop gain. In accordance with another aspect, the switching regulator comprises: a resistance sensing element for providing the current output of the regulator, and having a resistance which varies with temperature; and a circuit for maintaining the output current limit at a level independent of the temperature of the sensing element. In addition, in accordance with one aspect, a method of providing a regulated voltage to a load is disclosed in which a substantially maximum output current limit of a switching regulator is maintained. In one aspect the method comprises: adjusting the maximum output current limit in response to a programmable signal independently of the loop gain. In accordance with a second aspect, the method comprises: maintaining the output current limit at a level independent of the temperature of the sensing element and a constant transient response to load perturbations as a function of temperature and current limit setting.

Adjustable current limit switching regulator with constant loop gain

A single stage current sense amplifier is described that generates a differential output that is proportional to a current through a sense resistor. The voltage across the sense resistor is Vsense. The current sense amplifier includes a differential transconductance amplifier having high impedance input terminals. An on-chip RC filter filters transients in the Vsense signal. A feedback circuit for each leg of the amplifier causes a pair of input transistors to conduct a fixed constant current irrespective of Vsense, which stabilizes the transconductance. A gain control resistor (Re) is coupled across terminals of the pair of input transistors and has Vsense across it. The current through the gain control resistor is therefore Vsensex1/Re. A level shifting circuit coupled to each of the input transistors lowers a common mode voltage at an output of the amplifier. Chopper circuits at the input and output cancel any offset voltages.

High side current sense amplifier

An efficiency measuring circuit may measure the efficiency of a DC-DC converter having a switching inductor with an internal DC resistance and a plurality of electronic switches that control current through the inductor. A duty cycle circuit may measure the duty cycle of current flowing through one of the electronic switches. A current sense circuit may measure the current flowing through one of the electronic switches. An inductor voltage sensor circuit may measure the voltage across the inductor. A computation circuit may compute the internal DC resistance of the switching inductor based in part on the duty cycle measured by the duty cycle circuit and the current measured by the current sense circuit. The computation circuit may also compute the efficiency of the DC-DC converter.

Growing community of inventors

Colorado Springs, CO, United States of America

Gregory Jon Manlove