AVDD

AVDD

200

VIN+

OPA314

AINP

AINM

GND

AVDD

Device

Input Driver

Device: 8-Bit, 1-MSPS,

Single-Ended Input

+

1.5 nF

+

±

ADS7040

SBAS676C – NOVEMBER 2014 – REVISED DECEMBER 2015

www.ti.com

9 Application and Implementation

NOTE

Information in the following applications sections is not part of the TI component

specification, and TI does not warrant its accuracy or completeness. TI’s customers are

responsible for determining suitability of components for their purposes. Customers should

validate and test their design implementation to confirm system functionality.

9.1 Application Information

The two primary circuits required to maximize the performance of a high-precision, successive approximation

register (SAR), analog-to-digital converter (ADC) are the input driver and the reference driver circuits. This

section details some general principles for designing the input driver circuit, reference driver circuit, and provides

some application circuits designed for the ADS7040.

9.2 Typical Applications

9.2.1 Single-Supply DAQ with the ADS7040

Figure 39. DAQ Circuit: Single-Supply DAQ

9.2.1.1 Design Requirements

The goal of this application is to design a single-supply digital acquisition (DAQ) circuit based on the ADS7040

with SNR greater than 49 dB and THD less than –70 dB for input frequencies of 5 kHz at a throughput of

1 MSPS.

9.2.1.2 Detailed Design Procedure

The input driver circuit for a high-precision ADC mainly consists of two parts: a driving amplifier and an

antialiasing filter. Careful design of the front-end circuit is critical to meet the linearity and noise performance of a

high-precision ADC.

22

Submit Documentation Feedback

Copyright © 2014–2015, Texas Instruments Incorporated

Product Folder Links: ADS7040