DNC

TEMP

V

OUT

V

IN

GND

DNC

NC

TRIM/NR

REF50xx

C

BYPASS

1 Fto10 F

m

m

C

L

1 Fto50 F

m

m

+V

SUPPLY

V

OUT

REF5020-EP, REF5025-EP, REF5040-EP, REF5050-EP

www.ti.com

SBOS471B – APRIL 2010 – REVISED JUNE 2015

9 Power Supply Recommendations

The maximum voltage drop between the input and output pin is 0.2 V. The minimum power supply voltage for the

this rule is the REF5020, which requires a minimum 2.7-V power supply for proper operation. The maximum

power supply voltage for the REF50xx series is 18 V. TI recommends adding a bypass capacitor of 1

μF to 10

μF at the input to compensate for the layout and power supply source impedance.

9.1 Basic Connections

Figure 34 shows the typical connections for the REF50xx. TI recommends a supply bypass capacitor ranging

from 1

Figure 34. Basic Connections

9.2 Low Dropout Voltage

The REF50xx family of voltage references features extremely low dropout voltage. With the exception of the

REF5020, which has a minimum supply requirement of 2.7 V, these references can be operated with a supply of

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

versus load plot is shown in Figure 6 in Typical Characteristics.

10 Layout

10.1 Layout Guidelines

•

Place the power-supply bypass capacitor as closely as possible to the VIN pin and ground pins. The

recommended value of this bypass capacitor is 1

μF to 10 μF. If necessary, additional decoupling

capacitance can be added to compensate for noisy or high-impedance power supplies.

•

Place a 1-µF noise filtering capacitor between the NR pin and ground.

•

The output must be decoupled with a 1-µF to 50-µF capacitor. In series with load capacitor, add an ESR of 1

Ω for the best noise performance.

•

A high-frequency, 1-µF capacitor can be added in parallel between the output and ground to filter noise and

help with switching loads as data converters.

Copyright © 2010–2015, Texas Instruments Incorporated

Submit Documentation Feedback

19

Product Folder Links: REF5020-EP REF5025-EP REF5040-EP REF5050-EP