Texas Instruments Corporation

Eeshan Miglani

Jagannathan Venkataraman

Visvesvaraya Appala Pentakota

Shagun Dusad

Narasimhan Rajagopal

Karthikeyan Gunasekaran

Prasanth K

Chirag Chandrahas Shetty

Neeraj Shrivastava

Sandeep Kesrimal Oswal

Jawaharlal Tangudu

Sarma Sundareswara Gunturi

Rahul Anand Sharma

Srinivas Kumar Reddy Naru

Viswanathan Nagarajan

Charls Babu

Santhosh Kumar Gowdhaman

Anand Hariraj Udupa

Nagalinga Swamy Basayya Aremallapur

Chandrasekhar Sriram

Himanshu Varshney

Nithin Gopinath

Sai Aditya Krishnaswamy Nurani

Harshit Moondra

Shivam Srivastava

Praxal Sunilkumar Shah

Pradeep G Nair

Shuaeb Fazeel

Sandeep Jhanwar

H Mohammed Shuaeb Fazeel

Kartik Goel

Analog-to-digital converter (ADC) circuitry including a delay domain ADC that outputs converted analog input data along with a delay domain clock. A clock delay driver outputs a digital domain clock, an early clock leading the digital domain clock signal, and a late clock lagging the digital domain clock. An output latch latches the ADC output by the digital domain clock signal. The circuitry includes a timing error detection circuit with inputs receiving the delay domain clock, the early clock, and the late clock. The timing error detection circuit outputs early and late fail flags responsive to detecting timing errors of the digital domain clock relative to the early and late clocks, respectively. Timing loop circuitry has an input coupled to the error flag output of the timing error detection circuitry, and an output coupled to a control input of the clock delay driver.

Tuning of data interface timing between clock domains

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

A voltage-to-delay converter converts input signals into delay signals, and includes: a first stage for receiving the input signals and for generating intermediate output signals, wherein timing of the intermediate output signals corresponds to voltages of the input signals, and wherein the first stage has a voltage source for providing a rail-to-rail voltage; and a second stage for receiving the intermediate output signals and for generating rail-to-rail output signals, wherein timing of the rail-to-rail output signals corresponds to the timing of the intermediate output signals, and wherein voltage of the rail-to-rail output signals corresponds to the rail-to-rail voltage. A voltage-to-delay converter block is also described. A circuit for receiving differential input signals, generating corresponding output signals, and removing common mode signals from the output signals is also described.

Differential voltage-to-delay converter with improved CMRR

In described examples, an analog to digital converter (ADC), having an input operable to receive an analog signal and an output operable to output a digital representation of the analog signal, includes a voltage to delay (VD) block. The VD block is coupled to the input of the ADC and generates a delay signal responsive to a calibration signal. A backend ADC is coupled to the VD block, and receives the delay signal. The backend ADC having multiple stages including a first stage. A calibration engine is coupled to the multiple stages and the VD block. The calibration engine measures an error count of the first stage and stores a delay value of the first stage for which the error count is minimum.

Calibration scheme for a non-linear ADC

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

Techniques maintaining receiver reliability, including determining a present attenuation level for an attenuator, wherein the attenuation level is set by a gain controller, determining a relative reliability threshold based on the present attenuation level, receiving a radio frequency (RF) signal, determining a voltage level of the received RF signal, comparing the voltage level of the received RF signal to the relative reliability threshold to determine that a reliability condition exists, and overriding, in response to the determination that the reliability condition exists, the present attenuation level set by the gain controller with an override attenuation level based on the present attenuation level.

Reliability handling for wireless transceivers

A circuit includes a filter, a first inverter, and a second inverter. The filter is coupled to an input of the first inverter. The second inverter includes an input and an output. The input of the second inverter is coupled to the output of the first inverter. The output of the second inverter is coupled to the input of the first inverter. The filter includes a notch filter and a bandpass filter.

Clock filter with negative resistor circuit

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

A system for converting a voltage into output codes includes logic gates for processing delay signals based on earlier and later arriving signals generated by preamplifiers, delay comparators for generating digital signals representative of most significant bits of respective codes, and for transmitting delay residue signals representative of less significant bits of the codes, and an auxiliary delay comparator for generating an auxiliary digital signal for use in generating the output codes. A system may include logic gates for generating delay signals based on earlier and later arriving signals, delay comparators for generating digital signals representative of most significant bits of respective codes, and for transmitting delay residue signals representative of less significant bits, and a multiplexer system for transmitting a selected one of the residue signals.

Delay folding system and method

A system includes a Zero IF transmitter having a mixer and a programmable gain stage. The Zero IF transmitter also includes an intermediate stage between the mixer and the programmable gain stage, wherein the intermediate stage is configured to decouple the mixer and the programmable gain stage.

Zero IF transmitter with decoupling between mixer and programmable gain stage

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

An analog-to-digital converter includes a voltage-to-delay device, such as a pre-amplifier array, for generating a delay signal based on a first voltage, and delay-based stages for generating digital signals based on the delay signal. In operation, the delay signal is transmitted to a first delay-based stage, or to an intermediate delay-based stage, bypassing the first delay-based stage, to overcome non-linearity of previous stages. If desired, different pre-amplifiers may be used to generate signals for calibration of different delay-based stages. The present disclosure may also involve converting to pseudo-static signals before signals are handed over to a calibration engine, to ease timing and preserve interface area and power. If desired, simple delay elements may be used to correct for non-linearity in a delay-based analog-to-digital converter. The present disclosure may be employed, if desired, in connection with any suitable cascade of non-linear stages.

Piecewise calibration for highly non-linear multi-stage analog-to-digital converter

A dynamic voltage-to-delay device may have voltage lines for receiving input signals during reset phases, and a current source, connected to the first and second voltage lines, for increasing voltages on the voltage lines during active phases. The voltage-to-delay device may also have comparators, connected to the voltage lines, for generating first and second output signals during the active phases when the voltages on the voltage lines reach a threshold voltage, such that a delay between the output signals is representative of a difference between voltages of the input signals. The voltage-to-delay device may have at least two current sources. The comparators may have a tail node to which a voltage is applied during a reset phase, and a current source for reducing the voltage at the tail node, and thereby reducing a threshold voltage during an active phase.

Sampling network with dynamic voltage detector for delay output

A circuit includes a filter, a first inverter, and a second inverter. The filter is coupled to an input of the first inverter. The second inverter includes an input and an output. The input of the second inverter is coupled to the output of the first inverter. The output of the second inverter is coupled to the input of the first inverter.

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Chhindwara, India

Eeshan Miglani