www.ti.com

APPLICATION INFORMATION

SUPPLY VOLTAGE

OUTPUT ADJUSTMENT (TRIM Pin)

1.2V

60kW

REF50xx

TEMP

V

OUT

V

IN

GND

TRIM

Bandgap

+V

SUPPLY

µ

T

µ

T

(10 A

m

at25 C)

°

BASIC CONNECTIONS

DNC

TEMP

V

OUT

V

IN

GND

DNC

NC

TRIM

REF50xx

+V

SUPPLY

10kW

1kW

470W

TEMPERATURE DRIFT

DNC

TEMP

V

OUT

V

IN

GND

DNC

NC

TRIM

REF50xx

C

BYPASS

1 Fto10 F

m

m

C

L

1 Fto50 F

m

m

+V

SUPPLY

V

OUT

Drift +

V

OUTMAX

V

OUT

Temp Range

(1)

REF5020,, REF5025

REF5030, REF5040

REF5045, REF5050

SBOS410 – JUNE 2007

The REF50xx is family of low-noise, precision

bandgap voltage references that are specifically

designed for excellent initial voltage accuracy and

The REF50xx family of voltage references features

drift. Figure 21 shows a simplified block diagram of

extremely low dropout voltage. With the exception of

the REF50xx.

the

REF5020,

which

has

a

minimum

supply

requirement

of

2.7V,

these

references

can

be

operated with a supply of 200mV above the output

voltage

in

an

unloaded

condition.

For

loaded

conditions, a typical dropout voltage versus load plot

is shown in Figure 6 of the Typical Characteristics.

The REF50xx provides a very accurate voltage

nominal value for the purpose of trimming system

errors by configuring the TRIM pin (pin 5). The TRIM

over a ±15mV range. Figure 23 shows a typical circuit

technique,

the

temperature

coefficients

of

the

resistors can degrade the temperature drift at the

output.

Figure 21. REF50xx Simplified Block Diagram

Figure 22 shows the typical connections for the

REF50xx.

A

supply

bypass

capacitor

ranging

between 1

μF to 10μF is recommended. A 1μF to

50

μF,

low-ESR

output

capacitor

The REF50xx is 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 the following equation:

Figure 22. Basic Connections

The REF50xx features a maximum drift coefficient of

3ppm/

°C for the high-grade version, and 8ppm/°C for

the standard-grade.

9

Copyright © 2007, Texas Instruments Incorporated

Submit Documentation Feedback

Product Folder Link(s): REF5020 REF5025 REF5030 REF5040 REF5045 REF5050