REF(MAX)

REF(MIN)

6

REF

V

V

Drift =

10

V

Temperature Range

·

§

u

¸

¨

u

©

¹

Bandgap

core

Buffer

Digital

Enable

Blocks

Inrush

EN

IN

GNDF

OUTS

Current

Vdd

GNDS

OUTF

Limit

15

REF3425-Q1, REF3430-Q1, REF3433-Q1, REF3440-Q1, REF3450-Q1

www.ti.com

SBAS901 – JULY 2018

Product Folder Links: REF3425-Q1 REF3430-Q1 REF3433-Q1 REF3440-Q1 REF3450-Q1

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Copyright © 2018, Texas Instruments Incorporated

9 Detailed Description

9.1 Overview

The REF34xx-Q1 devices are a family of low-noise, precision bandgap voltage references that are specifically

designed for excellent initial voltage accuracy and drift. The Functional Block Diagram is a simplified block

diagram of the REF34xx-Q1 showing basic band-gap topology.

9.2 Functional Block Diagram

9.3 Feature Description

9.3.1 Supply Voltage

The REF34xx-Q1 family of references features an extremely low dropout voltage. For loaded conditions, a typical

dropout voltage versus load is shown on the front page. The REF34xx-Q1 family features a low quiescent current

that is extremely stable over changes in both temperature and supply. The typical room temperature quiescent

current is 72 μA, and the maximum quiescent current over temperature is just 95 μA. Supply voltages below the

specified levels can cause the REF34xx-Q1 to momentarily draw currents greater than the typical quiescent

current. Use a power supply with a fast rising edge and low output impedance to easily prevent this issue.

9.3.2 Low Temperature Drift

The REF34xx-Q1 devices are designed for minimal drift error, which is defined as the change in output voltage

over temperature. The drift is calculated using the box method, as described by Equation 3:

(3)