–2.5 V

+2.5 V

+5 V

1

2

5

6

3

4

R

1

10 kΩ R

2

10 kΩ

–5 V

+5 V

OPA735

REF3425-EP

Copyright © 2017, Texas Instruments Incorporated

14

REF3425-EP, REF3430-EP, REF3433-EP, REF3440-EP

SBAS942A – DECEMBER 2018 – REVISED MARCH 2019

www.ti.com

Product Folder Links: REF3425-EP REF3430-EP REF3433-EP REF3440-EP

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Copyright © 2018–2019, Texas Instruments Incorporated

9.4 Device Functional Modes

9.4.1

EN Pin

When the EN pin of the REF34xx-EP is pulled high, the device is in active mode. The device must be in active

mode for normal operation. The REF34xx-EP can be placed in a low-power mode by pulling the ENABLE pin

low. When in shutdown mode, the output of the device becomes high impedance and the quiescent current of

the device reduces to 2 µA in shutdown mode. The EN pin must not be pulled higher than VIN supply voltage.

See the Thermal Information for logic high and logic low voltage levels.

9.4.2 Negative Reference Voltage

For applications requiring a negative and positive reference voltage, the REF34xx-EP and OPA735 can be used

to provide a dual-supply reference from a 5-V supply. Figure 18 shows the REF3425-EP used to provide a 2.5-V

supply reference voltage. The low drift performance of the REF34xx-EP complements the low offset voltage and

zero drift of the OPA735 to provide an accurate solution for split-supply applications. Take care to match the

temperature coefficients of R1 and R2.

Figure 18. REF3425-EP and OPA735 Create Positive and Negative Reference Voltages