Data converter circuits

Analog-to-digital converter (ADC) and digital-to-analog converter (DAC) circuits that can be quickly modified to meet your specific design needs

Each data converter circuit below includes step-by-step instructions with formulas allowing you to adapt the circuit to meet your unique design requirements. We've provided at least one recommended data converter for each circuit, but you can easily swap it with another device if you've found one that fits better with your design. Our circuits require a basic understanding of data converter concepts, so if you are new to data converter design, we highly recommend reviewing our TI Precision Labs (TIPL) training series.

Analog-to-digital converter (ADC) circuits

Low-power, small size, and cost optimized circuits

This section emphasizes low power ADC and amplifier circuits. Often these circuits total power dissipation is a function of the sampling rate and the documentation will explain this trade off. Frequently, these circuits also use a smaller physical PCB area, so often an example PCB layout and associated PCB area is covered in the document.

Low-power, small size, and cost optimized circuits
Driving SAR directly without a front-end buffer circuit (low power, low sampling speed DAQ)
Low-power sensor measurements: 3.3 V, 1ksps, 12-bit single-ended, dual supply circuit
Low-power sensor measurements: 3.3 V, 1ksps, 12-bit single-ended, single supply 12-bit, single-ended, single-supply circuit

Level translation input drive circuits

This section covers amplifier drive circuits that translate input voltage levels to ranges appropriate for the ADC input range. For example, an amplifier drive circuit may show how a ±15V range can be attenuated and shifted for operation with a 5V ADC. Furthermore, this section will show how the amplifier drive circuit is optimized for best settling, noise, and bandwidth.

Level translation input drive circuits
Circuit for driving a high-voltage SAR with an instrumentation amplifier
Circuit for driving high-voltage SAR ADC with a buffered instrumentation amplifier
Circuit for driving high-voltage SAR ADCs for high-voltage, true differential signal acquisition
Circuit to increase input range on an integrated analog front end (AFE) SAR ADC
High common-mode differential input voltage to ±10-V ADC input circuit
High-current battery monitor circuit: 0-10 A, 0-10 kHz, 18-bit
High-input impedance, true differential, analog front end (AFE) attenuator circuit for SAR ADCs
High voltage battery monitor circuit: ±20 V, 0-10 kHz, 18-bit fully differential
Single-Ended to differential signal conversion using an op amp and FDA for unipolar signals
Single-ended to differential circuit using an op amp and fully differential amplifier (FDA) for bipolar signals
Single-ended to differential using a two op-amp circuit
True differential, 4 × 2 MUX, analog front end, simultaneous-sampling ADC circuit
Circuit for detecting input floating on ADS8681 ADC

Low-level sensor input circuits

This section covers circuit design for different kinds of sensors and low-level inputs. For example, the gain scaling and component selection to connect a bridge sensor to an ADC is covered. Furthermore, RTD, thermocouples, and thermistors are covered.

Low-level sensor input circuits
Circuit for driving a switched-capacitor SAR ADC with an instrumentation amplifier
Circuit for driving a switched-capacitor SAR ADC with a buffered instrumentation amplifier
Circuit for driving an ADC with an instrumentation amplifier in high gain
Low-input bias-current front end SAR ADC circuit
High-side current shunt monitor circuit to 3-V single-ended ADC
Two-wire PT100 RTD measurement circuit with low-side reference
Three-wire PT100 RTD measurement circuit with high-side reference and two IDAC current sources
Three-wire PT100 RTD measurement circuit with low-side reference and one IDAC current source
Three-wire PT100 RTD measurement circuit with low-side reference and two IDAC current sources
Four-wire PT100 RTD measurement circuit with low-side reference
Two-channel, K-type thermocouple measurement circuit with internal temperature sensor CJC

Input protection, filtering and isolation circuits

This section covers how external devices like TVS and Schottky diodes can be used to protect ADC circuits. Furthermore, antialiasing filters and isolation circuits are covered.

Input protection, filtering and isolation circuits
±12-V voltage sensing circuit with an isolated amplifier and pseudo-differential input SAR ADC
±12-V voltage sensing circuit with an isolated amplifier and differential input SAR ADC
Anti-aliasing filter circuit design for single-ended ADC input using fixed cutoff frequency
Circuit showing overstress protection on ADC with integrated analog front end
Digitally-isolated ADS8689 circuit design
Reducing effects of external RC filter circuit on gain and drift error for integrated analog front ends (AFEs): ±10 V
Circuit for protecting low-voltage SAR ADC from electrical overstress with minimal impact on performance
Input protection for high-voltage ADC circuit with TVS diode
Circuit for protecting ADC with TVS diode and PTC fuse
Circuit for protecting ADS131M0x ADC from EOS

Commonly used auxiliary circuits

This section covers circuits that are commonly used with ADC systems. For example, a power supply design that shows how to generate a -0.3V negative supply for an ADC drive amplifier is covered. Other power supply options and ADC reverence drive circuits are also covered.

Commonly used auxiliary circuits
Isolated power supply, low-noise circuit: 5 V, 100 mA
Powering a dual-supply op amp circuit with one LDO

Digital-to-analog converter (DAC) circuits

Audio outputs

Circuits and design techniques for high-performance audio systems, optimizing signal-to Noise ratio (SNR), total-harmonic-distortion (THD), and other AC specifications critical for audio applications.

Audio outputs
Active-filtering circuit for audio DAC
Auxiliary circuits for high-performance audio
Current-to-voltage converter circuit for audio DACs

Auxiliary and biasing circuits

Programmable open or closed loop voltage or current sources commonly used in adaptive voltage scaling, comparator, sensor excitation, or other calibration and biasing applications.

Auxiliary and biasing circuits
Circuit for offset adjustment of input signals using precision DAC for measurement equipment
DAC force and sense reference drive circuit
Power-supply margining circuit for LDOs using a precision DAC
Power-supply margining circuit for SMPS using a precision DAC

Current sources

High-side, low-side, and bi-directional current source or sink circuits commonly used for both control and biasing applications.

Current sources
Loop-powered 4- to 20-mA transmitter circuit
Programmable low-side current sink circuit
Programmable, two-stage, high-side current source circuit

Voltage sources

High-voltage and low-voltage single-ended or differential circuits along with options for high-current drive, capacitive load compensation, and positive and negative sense connections.

Voltage sources
Circuit for differential output from a single-ended precision DAC
High-current voltage output circuit using a precision DAC
Programmable voltage output with sense connections circuit
Unipolar negative voltage source from unipolar DAC circuit
Unipolar voltage output DAC to bipolar voltage output circuit