TPL0401A/B-10

I

WIPER

REGISTER

SCL

SDA

GND

VDD

W

H

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11

TPL0401A

TPL0401B

www.ti.com

SLIS144B – SEPTEMBER 2011 – REVISED FEBRUARY 2017

Product Folder Links: TPL0401A TPL0401B

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Copyright © 2011–2017, Texas Instruments Incorporated

9 Detailed Description

9.1 Overview

The TPL0401x-10 has a single linear-taper digital potentiometer with 128 wiper positions and an end-to-end

resistance of 10 kΩ. The potentiometer can be used as a three-terminal potentiometer. The main operation of

TPL0401x-10 is in voltage divider mode.

The low (L) terminal of the TPL0401x-10 is tied directly to GND. The high (H) and low (GND) terminals of

TPL0401-10 are equivalent to the fixed terminals of a mechanical potentiometer. The H terminal must have a

higher voltage than the low terminal (GND). The position of the wiper (W) terminal is controlled by the value in

the Wiper Resistance (WR) 8-bit register. When the WR register contains all zeroes (zero-scale), the wiper

terminal is closest to its L terminal. As the value of the WR register increases from all zeroes to all ones (full-

scale), the wiper moves from the position closest to the GND terminal to the position closest to the H terminal. At

the same time, the resistance between W and GND increases, whereas the resistance between W and H

decreases.

9.2 Functional Block Diagram

9.3 Feature Description

The TPL0401x-10 device is a single-channel, linear taper digital potentiometer with 128 wiper positions. Default

power up state for the TPL0401x-10 is mid code (0×40). The TPL0401x-10 has the low terminal connected to

a 6-pin SOT package with a specified temperature range of –40°C to +125°C. The part has a 10-kΩ end-to-end

resistance and can operate with a supply voltage range of 2.7 V to 5.5 V. This kind of product is widely used in

setting the voltage reference for low power DDR3 memory. The TPL0401x-10 has the low terminal internal and

connected to GND.

9.4 Device Functional Modes

9.4.1 Voltage Divider Mode

The digital potentiometer generates a voltage divider when all three terminals are used. The voltage divider at

wiper-to-H and wiper-to-GND is proportional to the input voltage at H to L (see Figure 11).