Texas Instruments Corporation

Avinash Shreepathi Bhat

BoQiang Xiao

Vadim Valerievich Ivanov

Rajat Chauhan

Joseph Alan Sankman

Chizim Obinuchi Okpara

In an example, a circuit includes an input stage having a control voltage input, a feedback input, a first control output and a second control output. The feedback input is coupled to a driver output. A first path stage has a first voltage input and a third output. The first voltage input is coupled to the first control output, and the third output is coupled to the driver output. A second path stage has a second voltage input and a fourth output. The second voltage input is coupled to the second control output, and the fourth output is coupled to the driver output. A load transistor has a control input coupled to the driver output. The input stage is configured to provide gm-boosting to the first path stage to turn on the load transistor responsive to an output voltage at a voltage output.

Low output impedance driver circuits and systems

A bandgap current reference circuit includes a bandgap core circuit and an error amplifier. The bandgap core circuit is configured to generate a zero temperature coefficient bandgap current. The bandgap core circuit includes a bipolar transistor. The bipolar transistor is configured to pass a current that is proportional to absolute temperature (PTAT current). The error amplifier is coupled to the bandgap core circuit and includes a bipolar differential input pair. The bipolar differential input pair is configured to ensure that the PTAT current is flowing in the bipolar transistor.

Bandgap current reference

A linear voltage regulator includes a voltage input and a voltage output. The linear voltage regulator includes a buffer having a voltage node, an input node, an output node and a control node and a power transistor having a control node coupled to the output node of the buffer, an input node coupled to the voltage input and an output node coupled to the voltage output. The linear voltage regulator includes a dropout detection module having a control node coupled to the control node of the power transistor, a voltage input node coupled to the voltage input, a voltage output node coupled to the voltage output and an output node. The linear voltage regulator includes a feedforward module having an input node coupled to the output node of the dropout detection module and an output node coupled to the control node of the buffer.

Linear voltage regulator

A linear regulator includes a pass transistor, a buffer transistor, and a low-pass filter circuit. The pass transistor is configured to pass a current from an input terminal to an output terminal. The buffer transistor is coupled to the input terminal and the pass transistor, and is configured to control the pass transistor. The low-pass filter circuit is coupled to the input terminal and the buffer transistor, and is configured to modulate a threshold voltage of the buffer transistor responsive to a transient at the input terminal.

Line transient improvement through threshold voltage modulation of buffer-FET in linear regulators

In a linear regulator system, a pass element has a control terminal, an input terminal and an output terminal. The pass element is configured to provide an output voltage at the output terminal based on: an input voltage at the input terminal; and a control signal at the control terminal. A dropout error amplifier has an error output and first and second inputs. The first input is coupled to the output terminal, and the error output is coupled to the control terminal. The dropout error amplifier is configured to provide a dropout control signal at the error output based on a comparison between: the output voltage at the first input; and a dropout reference voltage at the second input. The pass element is configured to regulate the output voltage at the dropout reference voltage, responsive to the dropout control signal.

Load current based dropout control for continuous regulation in linear regulators

An electronic circuit includes a first transistor, a second transistor, and a variable resistor. The first transistor has a first threshold voltage. The second transistor has a second threshold voltage that is different from the first threshold voltage. The second transistor is coupled to the first transistor. The variable resistor is coupled to the first transistor and the second transistor. The variable resistor is configured to adjust a temperature coefficient of the electronic circuit. The electronic circuit is configured to generate a reference voltage based on a difference of the first threshold voltage and the second threshold voltage.

Voltage threshold gap circuits with temperature trim

A linear regulator system is described. The linear regulator system includes a linear regulator core circuit including a pass element adapted to provide an output voltage, and a voltage error amplifier circuit coupled to the pass element and adapted to regulate the output voltage to form a regulated output voltage, based on an output reference voltage. The linear regulator core circuit further includes a current limit circuit comprising a current limit switch element coupled to the voltage error amplifier circuit and adapted to selectively modulate the output reference voltage of the voltage error amplifier circuit to form a current limited reference voltage, based on a current limit control signal received at a current limit control terminal associated therewith, in order to limit a load current through the pass element from exceeding a predefined maximum allowable load current limit.

Current limit through reference modulation in linear regulators

A power-on reset (POR) circuit includes first, second and third resistors. A first transistor has a first control terminal and first and second voltage terminals. A second transistor has a second control terminal and third and fourth voltage terminals. A third transistor has a third control terminal and fifth and sixth voltage terminals. The first control terminal is coupled via the first resistor to the second voltage terminal. The third voltage terminal is coupled via the second resistor to the first voltage terminal. The second control terminal is coupled via the third resistor to the fourth voltage terminal. The third control terminal is coupled to the third voltage terminal. The fifth voltage terminal is coupled to the first control terminal. A voltage buffer is coupled to the fifth voltage terminal.

Power-on reset circuit

A current reference circuit includes a native metal oxide semiconductor field effect transistor (MOSFET). The native MOSFET includes a source terminal coupled to ground. The current reference circuit also includes a transistor and an amplifier circuit. The transistor includes a first terminal coupled to a drain terminal of the native MOSFET, a second terminal coupled to a power supply rail, and a third terminal coupled to the drain terminal of the native MOSFET. The amplifier circuit includes an input terminal coupled to the drain terminal of the native MOSFET, and an output terminal coupled to a gate terminal of the native MOSFET.

Current reference circuit

In one example, a power-on reset (POR) circuit comprises a first transistor coupled to a voltage source, a control terminal of the first transistor coupled to a non-control terminal of the first transistor via a resistor; a second transistor coupled to the resistor, a control terminal of the second transistor is coupled to a non-control terminal of the second transistor; and a comparator having first and second terminals, the first terminal coupled to the non-control terminal of the first transistor and the second terminal coupled to the voltage source via an offset circuit.

A bandgap voltage circuit with a first circuit to generate an output voltage as a sum of a first voltage with an amplitude that is proportional to absolute temperature, and a first feedback voltage with an amplitude that is complementary to absolute temperature, a second circuit to generate a voltage having an amplitude that is complementary to absolute temperature, a scaling circuit to generate a second feedback voltage with an amplitude that is a fraction of the voltage of the control terminal, and a regulator circuit to regulate the first feedback voltage according to the second feedback voltage by controlling a first input current of the first circuit and a second input current of the second circuit.

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Tucson, AZ, United States of America

Avinash Shreepathi Bhat