REF35xxx

CIN

GND

VIN

EN

NR

VREF

GND

Optional

CL

High-pass

Filter

Fc = 0.07Hz

Low Noise

Preamplifier

G = 1000

2

nd Order

High-pass

Filter

Fc = 0.1Hz

G = 10

2

nd Order

Low-pass

Filter

Fc = 10Hz

G = 10

2

nd Order

Low-pass

Filter

Fc = 10Hz

G = 1

Oscilloscope

Supply

Buffer

Figure 8-10. Low-Frequency (1/f) Noise Test Setup

Time (1sec/div)

GND

Figure 8-11. 0.1 Hz to 10 Hz Voltage Noise

Figure 8-12 shows the typical 1/f noise (0.1 Hz to 10 Hz) distribution across various load conditions. REF35

device also offers noise reduction functionality by adding an optional capacitor between NR (pin 5) and ground

pins.

Figure 8-13 shows the typical 1/f noise (0.1 Hz to 10 Hz) distribution across REF35 devices with various

capacitance between NR pin and GND.

REF35

SNAS809A – DECEMBER 2021 – REVISED AUGUST 2022

www.ti.com

16

Submit Document Feedback

Copyright © 2022 Texas Instruments Incorporated

Product Folder Links: REF35