Drift +

V

OUTMAX

V

OUT

Temp Range

DNC

TEMP

V

OUT

V

IN

GND

DNC

NC

TRIM/NR

REF50xx

1 F

m

+V

SUPPLY

DNC

TEMP

V

OUT

V

IN

GND

DNC

NC

TRIM/NR

REF50xx

+V

SUPPLY

10kW

1kW

470W

REF5020-Q1, REF5025-Q1, REF5030-Q1

REF5040-Q1, REF5045-Q1, REF5050-Q1

SBOS456G – SEPTEMBER 2008 – REVISED OCTOBER 2013

www.ti.com

USING THE TRIM/NR PIN

the output voltage from the nominal value by configuring the trim and noise reduction pin (TRIM/NR, pin 5). The

TRIM/NR pin provides a ±15-mV adjustment of the device bandgap, which produces a ±15-mV change on the

temperature coefficients of the resistors can degrade the temperature drift at the output.

The REF50xx allows access to the bandgap through the TRIM/NR pin. Placing a capacitor from the TRIM/NR pin

to GND (as Figure 28 illustrates) in combination with the internal 1-k

Ω resistor creates a low-pass filter that

a corner frequency of 14.5 Hz. Higher capacitance results in a lower cutoff frequency.

Figure 28. Noise Reduction Using TRIM/NR Pin

TEMPERATURE DRIFT

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:

(1)

The REF50xx features a maximum drift coefficient of 8 ppm/°C for the standard-grade.

10

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