Bandgap

Voltage

Reference

CFILT = 1 µF

CL = 47 µF

RESR = 5

PŸ

RFILT

Buffer

+

VIN

OUT_S

OUT_F

FILT

VIN

GND_S

GND_F

Power Supply

SS

REF60xx

RLIM = 120

NŸ

EN

GND

REF

+

VIN

R = 1

NŸ

RF = 5

Ÿ

CF = 10 nF

THS4521

AINP

AINN

ADS8881

Copyright © 2016, Texas Instruments Incorporated

R = 1

NŸ

R = 1

NŸ

R = 1

NŸ

RF = 5

Ÿ

Power Supply

24

REF6025, REF6030, REF6033, REF6041, REF6045, REF6050

SBOS708B – MAY 2016 – REVISED AUGUST 2016

www.ti.com

Product Folder Links: REF6025 REF6030 REF6033 REF6041 REF6045 REF6050

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Copyright © 2016, Texas Instruments Incorporated

10 Applications 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.

10.1 Application Information

Many applications, such as event-triggered and multiplexed data-acquisition systems, require the very first

conversion of the ADC to have 18-bit or greater precision. These types of data acquisition systems capture data

in bursts, and are also called burst-mode, data-acquisition systems. Achieving 18-bit precision for the first sample

is very difficult using a conventional voltage reference because the voltage reference droop limits the accuracy of

the first few conversions. Furthermore, variable-sampling-rate systems require that the gain error of the system

does not vary with sampling rate. The primary objective of this design example is to demonstrate the lowest

distortion and noise, burst-mode data-acquisition block with low power consumption, using an 18-bit SAR ADC

operating at a throughput of 1 MSPS, for a 1-kHz, full-scale, pure sine-wave input.

10.2 Typical Application

Figure 54. 18-bit, 1-MSPS, Burst-Mode Data Acquisition system

10.2.1 Design Requirements

1. Burst-mode support (see Reference Droop Measurements section for more details)

2. ENOB > 16 bits

3. THD < –120 dB

4. Power consumption < 50 mW

5. Throughput = 1 MSPS