Texas Instruments Corporation

Sanjeev Manandhar

Kishan Joshi

Raveesh Magod Ramakrishna

Gary S Gibson

In an example, an apparatus includes an error amplifier, a buffer, a transistor, and a current-mode feedforward ripple canceller (CFFRC). The error amplifier has an amplifier output, a first input, and a second input, the error amplifier second input configured to receive a reference voltage. The buffer has a buffer input and a buffer output, the buffer input coupled to the error amplifier output. The transistor has a gate, a source, and a drain, the gate coupled to the buffer output, the drain coupled to the first input. The transistor is configured to receive an input voltage (VIN) at the source and provide an output voltage at the drain. The CFFRC has a CFFRC input and a CFFRC output, the CFFRC output coupled to the gate, and the CFFRC input configured to receive VIN.

Current-mode feedforward ripple cancellation

A system includes a low dropout regulator (LDO) circuit. The LDO circuit includes an error amplifier with an input node, a reference node, and an output node. The LDO circuit also includes a pass transistor with a control terminal, a first current terminal, and a second current terminal. The control terminal is coupled to the output node of the error amplifier, the first current terminal is coupled to a voltage source node, and the second current terminal is coupled to an LDO output node. The LDO output node is coupled to the input node of the error amplifier. The LDO circuit also includes a switched-capacitor network coupled between error amplifier and the pass transistor. The switched-capacitor network comprises a pair of switches and a current-controlled oscillator coupled to control terminals of the switches.

Low dropout regulator (LDO) with frequency-dependent resistance device for pole tracking compensation

First and second transconductance amplifier input stages having first and second gain characteristics, respectively, are combined. The resulting combined input stage has a third gain characteristic with a linear range that is larger than a linear range of either of the first and second gain characteristics.

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Tuscon, AZ, United States of America

Sanjeev Manandhar