APPLICATION INFORMATION

SUPPLY VOLTAGE

OUTPUT ADJUSTMENT USING THE TRIM/NR

R5

60kW

REF50xx

TEMP

V

OUT

GND

TRIM/NR

V

IN

a

T

a

T

(10 A

m

at+25 C)

°

R2

R1

R3

R4

10kW

1kW

1.2V

BASIC CONNECTIONS

DNC

TEMP

V

OUT

V

IN

GND

DNC

NC

TRIM/NR

REF50xx

+V

SUPPLY

10kW

1kW

470kW

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

REF5010

,, REF5020

REF5025, REF5030

REF5040, REF5045, REF5050

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.

PIN

The

REF50xx

provides

a

very

accurate,

be adjusted using the trim and noise reduction pin

(TRIM/NR, pin 5). Figure 23 shows a typical circuit

that allows an output adjustment of ±15mV

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 output capacitor (C

or equal to 1.5

Ω to ensure output stability. To

Pin

between 1

Ω and 1.5Ω.

The REF50xx allows access to the bandgap through

the TRIM/NR pin. Placing a capacitor from the

TRIM/NR pin to GND (see Figure 24) in combination

low-pass filter. A capacitance of 1

µF creates a

low-pass filter with the corner frequency between

10Hz and 20Hz. Such a filter decreases the overall

capacitance results in a lower filter cutoff frequency,

further reducing output noise. Note that use of this

capacitor increases startup time.

Figure 22. Basic Connections

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Product Folder Link(s): REF5010 REF5020 REF5025 REF5030 REF5040 REF5045 REF5050