REF3112-Q1 Datasheet, PDF (15/23 Pages) Texas Instruments – 15 ppm Maximum, 100-uA, SOT-23 Series Voltage Reference

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9 Application and Implementation
REF3112-Q1, REF3120-Q1, REF3125-Q1
REF3130-Q1, REF3133-Q1, REF3140-Q1
SBVS299 – APRIL 2017
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.
V_IN
1
0.47mF _{REF31xx-Q1 3}
V_OUT
2
Copyright © 2016, Texas Instruments Incorporated
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.
3.3 V ^REF3130-Q1 3.0 V
IN OUT
+
+ _VIN
±5 V –
–
1.25 V
R2
20 kO
R1
R3
100 kO
20 kO
3.0 V
+
OPA317
VOUT
R4
100 kO
R5
10 kO
MSP430F2013
Launchpad
J1.2/A1+
J1.3/A1–
3.3 V
IN+ SD_16
SA-ADC
IN–
3.0 V ^REF3112-Q1 1.25 V
IN OUT
R6
47 kO
R7
47 kO
0.625 V
C2
47 µF
J1.5/VREF
Copyright © 2016, Texas Instruments Incorporated
Figure 29. Low-Power Reference and Bipolar Voltage Conditioning Circuit for Low-Power ADCs
Copyright © 2017, Texas Instruments Incorporated
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Product Folder Links: REF3112-Q1 REF3120-Q1 REF3125-Q1 REF3130-Q1 REF3133-Q1 REF3140-Q1