42.5

42.0

41.5

41.0

40.5

40.0

1

1.5

2

2.5

3

3.5

4

4.5

5

5.5

6

V

(V)

IN

R

1

Q

2

Q

1

+

Vbe

1

+

Vbe

2

REF3012, REF3020, REF3025, REF3030, REF3033, REF3040

www.ti.com

SBVS032G – MARCH 2002 – REVISED NOVEMBER 2015

8 Detailed Description

8.1 Overview

The REF30xx is a series, CMOS, precision bandgap voltage reference. Its basic topology is shown in the

curvature of the bandgap voltage, as shown in Figure 3, is due to the slightly nonlinear temperature coefficient of

8.2 Functional Block Diagram

8.3 Feature Description

8.3.1 Supply Voltage

The REF30xx family of references features an extremely low dropout voltage. With the exception of the

REF3012, which has a minimum supply requirement of 1.8 V, the REF30xx can be operated with a supply of

only 1 mV above the output voltage in an unloaded condition. For loaded conditions, a typical dropout voltage

versus load is shown on the front page.

The REF30xx features a low quiescent current that is extremely stable over changes in both temperature and

supply. The typical room temperature quiescent current is 42

μA, and the maximum quiescent current over

temperature is just 59

μA. Additionally, the quiescent current typically changes less than 2.5 μA over the entire

supply range, as shown in Figure 24.

Supply voltages below the specified levels can cause the REF30xx 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.

Figure 24. Supply Current vs Supply Voltage

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Product Folder Links: REF3012 REF3020 REF3025 REF3030 REF3033 REF3040