7.2.1.2 Detailed Design Procedure

When using the REF1112 as a reference, determine the following:

• Supply voltage range

• Current source resistance

• Reference voltage accuracy

To design using the REF1112, make sure that the VS is larger than VREF.

The resistor RBIAS sets the cathode current of the REF1112, IR. Make sure that this current remains in the

operational region of the part for the entire VS and load range.

Using this information, select a RBIAS such that:

IREFMIN < IREF < IREFMAX where IREFMAX = 5mA.

In this application the IREF is the operating current of the REF1112 plus the maximum possible ILOAD under

no-load conditions.

7.2.2 MicroPOWER 3μA, 1V Voltage Reference

0.1μF

3V

3V

V

REF

V

OUT = 1V

795k

Ω

250k

Ω

1M

Ω

REF1112

TLV2401

Copyright © 2018, Texas Instruments Incorporated

Figure 7-2. MicroPOWER 3μA, 1V Voltage Reference

7.2.2.1 Design Requirements

The REF1112 can be scaled to provide extremely low power reference voltages. Figure 7-2 shows the REF1112

used as a 1V VOUT, 3μA voltage reference.

7.2.2.2 Detailed Design Procedure

Set RBIAS such that the current through the shunt reference, IREF, is greater than IREFMIN + ILOAD.

Use a resistor divider to set the required voltage to the input of the amplifier. The TLV2401 requires an input bias

current maximum of 350pA which allows the use of larger resistor values to save power.

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REF1112

SBOS283E – SEPTEMBER 2003 – REVISED DECEMBER 2024

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Product Folder Links: REF1112