Texas Instruments Corporation

Neeraj Shrivastava

Visvesvaraya Appala Pentakota

Shagun Dusad

Narasimhan Rajagopal

Ani Xavier

Arun Kumar Mohan

Jagannathan Venkataraman

Eeshan Miglani

Viswanathan Nagarajan

Srinivas Kumar Reddy Naru

Chirag Chandrahas Shetty

Jafar Sadique Kaviladath

Harshit Moondra

Prasanth K

Nithin Gopinath

Ajai Paulose

Jaiganesh Balakrishnan

Nagarajan Viswanathan

Aravind Ganesan

Rishi Soundararajan

Himanshu Varshney

Yeswanth Guntupalli

Sai Aditya Nurani

Roswald Francis

Visvesvaraya Pentakota Appala

Mathews John

Abhinav Chandra

Sai Vikas Kandimalla

Nitin Kumar Agarwal

Jawaharlal Tangudu

Pankaj Gupta

Sreenath Narayanan Potty

Anand Hariraj Udupa

Rajendrakumar Joish

Chandrasekhar Sriram

Charls Babu

Sai Aditya Krishnaswamy Nurani

Raju Kharataram Chaudhari

Divyeshkumar Mahendrabhai Patel

Shivam Srivastava

Supreet Joshi

Mahesh Ravi Varma

Shabbar Abbasi Vejlani

Keshav Tiwari

Abhijith N

Samriddh Bhalla

Prabhansh Pandey

A circuit includes a nonlinear analog-to-digital converter (ADC) configured to provide a first digital output based on an analog input signal. The circuit also includes a linearization circuit having a lookup table (LUT) memory configured to store initial calibration data. The linearization circuit is coupled to the nonlinear ADC and is configured to: determine updated calibration data based on the initial calibration data; replace the initial calibration data in the LUT memory with the updated calibration data; and provide a second digital output at a linearization circuit output of the linearization circuit based on the first digital output and the updated calibration data.

Analog-to-digital converter (ADC) having linearization circuit with reconfigurable lookup table (LUT) memory and calibration options

In an example, a system includes a pipelined analog-to-digital converter (ADC) having a main path and an auxiliary path. The main path includes a first stage having a sampling switch, a flash ADC having an input coupled to the sampling switch, a digital-to-analog converter (DAC) having an input coupled to an output of the flash ADC, and a first amplifier having an input coupled to an output of the DAC and the sampling switch. The main path includes a second stage coupled to the first stage and an input of a second amplifier. The main path also includes a backend ADC having an input coupled to an output of the second amplifier. The auxiliary path includes a plurality of metastability comparators coupled to the flash ADC.

Metastability error detection and BER improvement technique in pipelined ADCs

A voltage-to-delay converter includes a first reset transistor having a first terminal coupled to a power supply terminal, a gate terminal receiving a reset signal, and a second terminal coupled to a top plate of a first integrating capacitor, and a second reset transistor having a first terminal coupled to a power supply terminal, a gate terminal receiving the reset signal, and a second terminal coupled to a top plate of a second integrating capacitor. First and second input transistors receive first and second input voltages, and are coupled between the top plate of the first and second integrating capacitors, respectively, and a first current source. A discharge current source is coupled to bottom plates of the first and second integrating capacitors. A pulse generator has first and second inputs coupled to the top plate of the first and second integrating capacitors, respectively.

Voltage-to-delay converter

An analog-to-digital converter circuit module utilizing dither to reduce multiplicative noise. A dither generation circuit generates a noise-shaped analog dither signal having lower amplitudes at frequencies below a cutoff frequency than at frequencies above the cutoff frequency. The noise-shaped analog dither signal is added to the input analog signal to be converted and the summed signal applied to an analog-to-digital converter The dither generation circuit may be implemented as an analog dither generator followed by an analog high-pass filter. The dither generation circuit may alternatively be implemented digitally, for example with a digital noise-shaping filter applying a high-pass digital filter to a pseudo-random binary sequence. The digital dither generation circuit may alternatively be implemented by one or more 1-bit sigma-delta modulators, each generating a bit of a digital dither sequence that is converted to analog.

Noise-shaping of additive dither in analog-to-digital converters

In described examples, a circuit includes a multiplexer. The multiplexer receives an input voltage and a calibration signal. An analog-to-digital converter (ADC) is coupled to the multiplexer and generates an output code in response to the calibration signal. A storage circuit is coupled to the ADC and stores the input code representative of the calibration signal at an address corresponding to the output code. The stored input code includes an index value and a coarse value.

Lookup table for non-linear systems

In described examples, a circuit includes a calibration engine. The calibration engine generates multiple input codes. A digital to analog converter (DAC) is coupled to the calibration engine, and generates a first calibration signal in response to a first input code of the multiple input codes. An analog to digital converter (ADC) is coupled to the DAC, and generates multiple raw codes responsive to the first calibration signal. A storage circuit is coupled to the ADC and stores a first output code corresponding to the first input code. The first output code is obtained using the multiple raw codes generated by the ADC.

Calibration scheme for filling lookup table in an ADC

A method of using an analog-to-digital converter system includes receiving a sampled voltage corresponding to one of an input voltage and a known voltage, causing preamplifiers to generate output signals based on the sampled voltage, generating first and second signals based on the output signals, causing a delay-resolving delay-to-digital backend to generate a single-bit digital signal representing an order of receipt of the first and second signals, and adjusting one or more of the preamplifiers based on the digital signal. The disclosure also relates to a system which includes a voltage-to-delay frontend and a delay-resolving backend, and to a method which includes causing a delay comparator to generate a single-bit digital signal representing an order of receipt of input signals, causing the comparator to transmit a residue delay signal to a succeeding comparator, and transmitting a signal to adjust one or more of the preamplifiers based on the digital signal.

Gain mismatch correction for voltage-to-delay preamplifier array

An analog-to-digital converter system includes a digital-to-analog converter for generating calibration voltages based on digital input codes, and an analog-to-digital converter, connected to the digital-to-analog converter, for receiving the calibration voltages from the digital-to-analog converter, for receiving sampled voltages, for generating digital output codes based on the calibration voltages, and for generating digital output codes based on the sampled voltages. The analog-to-digital converter system may have a lookup table, connected to the analog-to-digital converter, for storing the first digital output codes in association with the digital input codes. A method of calibrating an analog-to-digital converter system is also disclosed.

Lookup-table-based analog-to-digital converter

A non-linearity correction circuit includes a non-linearity coefficient estimation circuit. The non-linearity coefficient estimation circuit includes a data capture circuit, a non-linearity term generation circuit, a time-to-frequency conversion circuit, a bin identification circuit, a residual non-linearity conversion circuit, and a non-linearity coefficient generation circuit. The non-linearity term generation circuit is coupled to the data capture circuit. The time-to-frequency conversion circuit is coupled to the data capture circuit and the non-linearity term generation circuit. The bin identification circuit is coupled to the time-to-frequency conversion circuit. The residual non-linearity conversion circuit is coupled to the bin identification circuit. The non-linearity coefficient generation circuit is coupled to the bin identification circuit and the residual non-linearity conversion circuit.

Non-linearity correction

A one-time write, read-only memory for storing trimming parameters includes an address pointer table, a fixed packet portion, and a flexible packet portion. The fixed packet portion includes one or more fixed packets, each fixed packet including trimming parameters for a component identified for trimming during a design phase. The flexible packet portion includes one or more flexible packets of different types. Each flexible packet includes trimming parameters for a component identified for trimming after the design phase. One packet type includes a length section and a number of fields equal to a value stored in the length section. Each field includes an address, a trimming parameter, and a mask. Another packet type includes trimming parameters associated with operands in operating instructions for a microcontroller, where the operands include an address and a mask.

Flexible and efficient device trim support using eFuse

Flexible and efficient device trim support using efuse

A top-plate sampling analog-to-digital converter (ADC) circuit includes a first ADC stage and a residue amplifier coupled to the first ADC stage. The residue amplifier comprises a first transistor with a control terminal, a first current terminal, and a second current terminal. The residue amplifier also comprises a second transistor with a control terminal, a first current terminal, and a second current terminal. The residue amplifier also comprises a linearity adjustment circuit coupled to a second current terminal of at least one of the first transistor and the second transistor. The linearity adjustment circuit comprises at least one switch that changes its state as a function of an input sampling phase and a gain phase of the residue amplifier.

Top plate sampling analog-to-digital converter (ADC) with residue amplifier non-linearity reduction

An analog-to-digital converter including a first stage and a second stage. The first stage includes a first sample-and-hold (SH) having an input coupled to a voltage input node of the ADC, and having a first SH output. The first stage also includes a buffer, a first flash converter and a first digital-to-analog converter (DAC). The buffer has an input coupled to the first SH output and has a buffer output. The first flash converter has an input coupled to the first SH output, and has a first flash converter output. The first DAC has an input coupled to the first flash converter output. The second stage includes a second flash converter having an input coupled to the buffer output.

Pipelined analog-to-digital converter

A digital step attenuator (DSA) includes a switch control circuit which receives the attenuated signal output by the DSA from a buffer and generates a tracked control signal for switches within the DSA. Some switch control circuits include a capacitor coupled to receive the buffered signal, a supply voltage, and a switch control logic sub-circuit for each switch. Each switch control logic sub-circuit receives a control signal, for either the gate or the bulk terminal of the switch, and generates the tracked control signal. In other embodiments, switch control circuits include a complementary MOSFET switching device coupled to receive a control signal, and a capacitor coupled to receive the buffered signal, both of which are connected to an output terminal for the tracked control signal. In those embodiments, the DSA includes a switch control circuit for each switch connected to the DSA output.

Continuous time linear capacitive digital step attenuator

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Bengaluru, India

Neeraj Shrivastava