2 | www.intersil.com/DCPs-DCCs

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Resistor Ladder

Resolution: 4-bit to 10-bit

DCP

TSSOP, SC-70,

SOT-23, µTQFN

Pushbutton

Register Store

Volatile: RAM

Digital Control

Advantage

DCP

Mechanical Potentiometer

Reliability

Not susceptible to mechanical vibration & higher

tolerance to environmental factors.

Have moving parts, so can be more sensitive to

vibration, humidity, etc.

Power-up

DCPs with EEPROM will store setting until user

changes the value in memory (~100k to 1M

times).

If glue is used to prevent wiper movement, the

device setting cannot be changed.

Control

Digital control - reduced manufacturing costs and

enables factory automation

Manual control – increases setup time and

accuracy is reliant on technician

Size

Typically Smaller

Typically Larger

Advantage

DCP

DAC

Flexibility of

Output

Terminals

3 terminals allow use as either voltage divider

or variable resistor. Also allows user to change

voltage at terminal ends.

Terminals are usually fixed rail to rail. No flexibility

Power-up

Output Setting

Non-volatile DCPs have EEPROM where a user

can store power-up settings.

Output typically has default settings like Volatile

DCPs.

Digital

Interface

ADVANtAgeS of DCP vs. DeViCeS with SimilAr fuNCtioNS

WhAT IS A DCP?

Digitally Controlled Potentiometers are integrated circuits incorporating a resistor ladder with its associated registers, non-

volatile or volatile memory, and a digital interface providing direct communication between a host and both the resistor

ladder and memory.

register Store

DCP wiper position is stored in a

register. When power is reset, a volatile

DCP typically sets the wiper position to

midscale or zero-scale at power-up. When

the power is cycled for a nonvolatile DCP,

the last value stored in the EEPROM

register is recalled, which loads the initial

wiper value during power-up.

Digital Control

Digital control allows the user to select each

switch in a “make before break” mode,

transferring the potential to the wiper.

DIGITAL POTENTIOMETERS

DCP

overview

DCP Structure

DCP

= Digitally Controlled Potentiometer

tap

= Switch position on resistor string

wiper (Vw/rw)

= DCP output node

DCP oVerView

ACCESS CONTROL REGISTER (ACR)

VOL

SHDN

WIP

0

0

0

0

0

Only one

closes at

a time

TAP 1

TAP 2

TAP 127

TAP 128

resistor ladder

The resistor array is comprised of individual resistors

connected in series. There are electronic switches (taps)

at each resistor junction, which have a common output

node called a wiper (VW/RW). Each physical end of the

array is described as a terminal and referred to as VH/

RH and VL/RL, and the resistance between the terminals

DATA

8

1

CLOCK