Texas Instruments Corporation

Amal Kumar Kundu

Sovan Ghosh

Laxmi Vivek Tripurari

Minkle Eldho Paul

Janakiraman Seetharaman

Anand Subramanian

Anant Shankar Kamath

Rahul Vijay Kulkarni

Shridhar Atmaram More

Manish Mustafi

Described embodiments include a voltage level shifter with a first driver having an input that receives a first signal, an output, a positive supply terminal coupled to a first supply terminal, and a negative supply terminal coupled to a second supply terminal. A transistor has first and second current terminals and a first control terminal. The first current terminal is coupled to the first driver output, and the first control terminal is adapted to be coupled to a low-side drive transistor control terminal. A second driver has an input coupled to the second current terminal, an output, a positive supply terminal coupled to a third supply terminal, and a negative supply terminal coupled to ground. The second driver provides a second signal at the second driver output. A voltage at the third supply terminal is less than 10% of a voltage at the first supply terminal.

Level shifter for high voltage driver

A circuit includes first and second gain stages and an output transistor. The second gain stage includes a transconductance amplifier and a variable impedance circuit coupled to an output of the transconductance amplifier. The variable impedance circuit is configured to implement a first impedance level at frequencies below a first frequency threshold and to implement a second impedance level at frequencies above a second frequency level. The first impedance level is larger than the second impedance level. The output transistor has a control input coupled to the variable impedance circuit. At frequencies above the second frequency threshold, the second impedance level is configured to be inversely related to current through the output transistor.

Dynamic biasing circuit

A comparator having: a first transistor coupled to a first input terminal; a first current source coupled to the first transistor; a second transistor coupled to a second input terminal and coupled to the first current source; a third transistor coupled in series with the first transistor; a fourth transistor coupled in series with the second transistor; a fifth transistor coupled in series with the first transistor; a sixth transistor coupled in series with the second transistor; a seventh transistor coupled to the first input terminal and coupled as a source follower to the fifth transistor; and an eighth transistor coupled to the second input terminal and coupled as a source follower to the sixth transistor. The comparator also including a differential amplifier coupled to the first output terminal and coupled to the second output terminal.

Cascode bias for comparator

An analog-to-digital converter (ADC) circuit includes a signal input terminal, a sample-and-hold circuit, and a successive approximation register (SAR) ADC. The sample-and-hold circuit includes an input terminal coupled to the signal input terminal. The SAR ADC includes a comparator, a first capacitive digital-to-analog converter (CDAC), and a second CDAC. The first CDAC includes a first input terminal coupled to the signal input terminal, a second input terminal coupled to an output terminal of the sample-and-hold circuit, and an output terminal coupled to a first input terminal of the comparator. The second CDAC includes a first input terminal coupled to the signal input terminal, an output terminal coupled to a second input terminal of the comparator.

Analog-to-digital converter

An analog to digital (A/D) converter includes a capacitor array having respective first terminals selectively coupled to a reference voltage or ground via a plurality of switches and having respective second terminals coupled to a sample and hold (S/H) output. The A/D converter also includes a voltage comparator having a first input coupled to the S/H output and having a second input coupled to a bias voltage. The voltage comparator is configured to output a comparison voltage responsive to a sampled charge at the S/H output and the bias voltage. The A/D converter also includes a successive approximation register coupled to receive the comparison voltage and configured to output an approximate digital code responsive to the comparison voltage, wherein the approximate digital code is varied by controlling an equivalent capacitance of the capacitor array.

Analog to digital (A/D) converter with internal diagnostic circuit

A comparator circuit includes a first transistor configured to receive a first input and a second transistor configured to receive a second input. The comparator circuit further includes a third transistor coupled to a terminal of each of the first and second transistors. The third transistor is configured to be controlled by a first control signal. A gate of a fifth transistor is coupled to a terminal of a fourth transistor at a first node and a gate of the fourth transistor is coupled to a terminal of the fifth transistor at a second node. A sixth transistor is coupled between the first and fourth transistors. A seventh transistor is coupled between the second and fifth transistors. A gate of the sixth transistor and a gate of the seventh transistor are coupled together at a fixed voltage level.

Reduced noise dynamic comparator for a successive approximation register analog-to-digital converter

An analog-to-digital converter includes a low voltage power supply rail, a high voltage power supply rail, successive approximation circuit, a level shifter, and a capacitive digital-to-analog converter (CDAC). The successive approximation circuitry is coupled to the low voltage power supply rail. The level shifter is coupled to the high voltage power supply rail and includes inputs coupled to first outputs of the successive approximation circuitry. The CDAC includes a first segment and a second segment. The first segment includes a first plurality of capacitors, and a first plurality of switches coupled to outputs of the level shifter. The second segment includes a second plurality of capacitors, and a second plurality of switches coupled to second outputs of the successive approximation circuitry.

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Bengaluru, India

Amal Kumar Kundu