+

+

–

+

–

IN OUT

REF3112-Q1

IN

OUT

REF3130-Q1

3.3 V

1.25 V

20 kO

3.0 V

20 kO

OPA317

100 kO

10 kO

3.0 V

1.25 V

3.3 V

IN+

IN–

SD_16

J1.2/A1+

J1.3/A1–

0.625 V

47 µF

47 kO

47 kO

±5 V

SA-ADC

3.0 V

MSP430F2013

Launchpad

100 kO

Copyright © 2016, Texas Instruments Incorporated

1

3

REF31xx-Q1

2

0.47 F

m

V

IN

V

OUT

Copyright © 2016, Texas Instruments Incorporated

15

REF3112-Q1, REF3120-Q1, REF3125-Q1

REF3130-Q1, REF3133-Q1, REF3140-Q1

www.ti.com

SBVS299 – APRIL 2017

Product Folder Links: REF3112-Q1 REF3120-Q1 REF3125-Q1 REF3130-Q1 REF3133-Q1 REF3140-Q1

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Copyright © 2017, Texas Instruments Incorporated

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 REF31xx-Q1 does not require a load capacitor and is stable with any capacitive load. Figure 28 shows

typical connections required for operation of the REF31xx-Q1. TI recommends a supply bypass capacitor of

0.47 μF.

Figure 28. Typical Connections for Operating REF31xx-Q1

9.2 Typical Application

Figure 29 shows a low-power reference and conditioning circuit. This circuit attenuates and level-shifts a bipolar

input voltage within the proper input range of a single-supply, low-power, 16-bit ΔΣ ADC, such as the one inside

the MSP430™ or other similar single-supply ADCs. Precision reference circuits are used to level-shift the input

signal, provide the ADC reference voltage, and to create a well-regulated supply voltage for the low-power

analog circuitry. A low-power, zero-drift, op-amp circuit is used to attenuate and level-shift the input signal.

Figure 29. Low-Power Reference and Bipolar Voltage Conditioning Circuit for Low-Power ADCs