8.4 Device Functional Modes

8.4.1 Basic Connections

Figure 8-6 shows the typical connections for the REF50xx. TI recommends a supply bypass capacitor ranging

from 1μF to 10μF. A 1μF to 50μF output capacitor (CL) must be connected from VOUT to GND. The equivalent

series resistance (ESR) value of CL must be less than or equal to 1.5Ω to make sure output stability. To minimize

noise, the recommended ESR of CL is from 1Ω and 1.5Ω.

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

Figure 8-6. Basic Connections

8.4.2 Supply 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 2.7V, these references can be operated with a supply of

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

versus load plot is provided in Figure 6-6.

8.4.3 Negative Reference Voltage

For applications requiring a negative and positive reference voltage, the REF50xx and OPA735 can be used to

provide a dual-supply reference from a 5V supply. Figure 8-7 shows the REF5025 used to provide a 2.5V supply

reference voltage. The low-drift performance of the REF50xx complements the low offset voltage and zero drift

of the OPA735 to provide an accurate solution for split-supply applications. Take care to match the temperature

coefficients of R1 and R2.

-

2.5V

+2.5V

+5V

NOTE:Bypasscapacitorsnotshown.

R

1

10kW

R

2

10kW

-

5V

OPA735

+5V

DNC

TEMP

V

OUT

V

IN

GND

DNC

NC

TRIM/NR

REF5025

1 F

m

Figure 8-7. The REF5025 and OPA735 Create Positive and Negative Reference Voltages

REF5010, REF5020, REF5025, REF5030, REF5040, REF5045, REF5050

SBOS410L – JUNE 2007 – REVISED OCTOBER 2024

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