Input voltage (V)

0

1

2

3

4

5

0

10

20

30

40

50

REF35-OSR0

REF35-OSR8

REF35-OSR128

LDO-OSR0

LDO-OSR8

LDO-OSR128

Figure 10-3. Error vs Input Voltage

10.3 Power Supply Recommendations

The REF35 family of references feature an extremely low-dropout voltage. These references can be operated

with a supply of only 50 mV above the output voltage at no load. TI recommends a supply bypass capacitor

ranging between 0.1 µF to 10 µF.

10.4 Layout

10.4.1 Layout Guidelines

Figure 10-4 shows an example of a PCB layout for a data acquisition system using the REF35. Some key

considerations are:

• Connect low-ESR, 0.1 μF ceramic bypass capacitors at VIN, VREF of the REF35.

• Decouple other active devices in the system per the device specifications.

• Using a solid ground plane helps distribute heat and reduces electromagnetic interference (EMI) noise

pickup.

• Place the external components as close to the device as possible.

• Do not run sensitive analog traces in parallel with digital traces. Avoid crossing digital and analog traces if

possible, and only make perpendicular crossings when absolutely necessary.

Figure 10-5 shows the pin compatibility with TI REF30xx, REF31xx and REF33xx series references in the

3-pin SOT-23 package when using the REF35xxx family footprint. You must rotate the REF30xx, REF31xx and

REF33xx reference devices by 180º before assembly.

www.ti.com

REF35

SNAS809A – DECEMBER 2021 – REVISED AUGUST 2022

Copyright © 2022 Texas Instruments Incorporated

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Product Folder Links: REF35