X9015 Ver la hoja de datos (PDF) - Renesas Electronics

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Fabricante

X9015

Low Noise, Low Power, Volatile Single Digitally Controlled (XDCP™) Potentiometer

Renesas Electronics 

X9015

Pin Descriptions

RH/VH and RL/VL

The high (RH/VH) and low (RL/VL) terminals of the X9015 are

equivalent to the fixed terminals of a mechanical potentiometer.

The minimum voltage is VSS and the maximum is VCC. The

terminology of RL/VL and RH/VH references the relative position

of the terminal in relation to wiper movement direction selected

by the U/D input, and not the voltage potential on the terminal.

RW/VW

RW/Vw is the wiper terminal and is equivalent to the movable

terminal of a mechanical potentiometer. The position of the

wiper within the array is determined by the control inputs. The

wiper terminal series resistance is typically 200 at VCC=5V.

At power up the wiper position is at Tap #15. (VL/RL=Tap #0).

Up/Down (U/D)

The U/D input controls the direction of the wiper movement and

whether the tap position is incremented or decremented.

Increment (INC)

The INC input is negative-edge triggered. Toggling INC will

move the wiper and either increment or decrement the counter

in the direction indicated by the logic level on the U/D input.

Chip Select (CS)

The device is selected when the CS input is LOW. When CS is

returned HIGH while the INC input is also HIGH the X9015 will

be placed in the low power standby mode until the device is

selected once again.

Pin Names

SYMBOL

RH/VH

RW/VW

RL/VL

VSS

VCC

U/D

INC

CS

DESCRIPTION

High terminal

Wiper terminal

Low terminal

Ground

Supply voltage

Up/Down control input

Increment control input

Chip select control input

Principles Of Operation

There are two sections of the X9015: the input control, counter

and decode section; and the resistor array. The input control

section operates just like an up/down counter. The output of this

counter is decoded to turn on a single electronic switch

connecting a point on the resistor array to the wiper output. The

resistor array is comprised of 31 individual resistors connected

in series.

The wiper, when at either fixed terminal, acts like its mechanical

equivalent and does not move beyond the last position. That is,

the counter does not wrap around when clocked to either

extreme.

The electronic switches on the device operate in a “make before

break” mode when the wiper changes tap positions. If the wiper

is moved several positions, multiple taps are connected to the

wiper for tIW (INC to VW change). The RTOTAL value for the

device can temporarily be reduced by a significant amount if the

wiper is moved several positions.

When the device is powered-down, the wiper position is lost.

When power is restored, the wiper is set to Tap #15.

Instructions and Programming

The INC, U/D and CS inputs control the movement of the wiper

along the resistor array. With CS set LOW the device is selected

and enabled to respond to the U/D and INC inputs. HIGH to

LOW transitions on INC will increment or decrement (depending

on the state of the U/D input) a five bit counter. The output of this

counter is decoded to select one of thirty two wiper positions

along the resistive array.

The system may select the X9015, move the wiper and deselect

the device. The new wiper position will be maintained until

changed by the system or until a power-up/down cycle.

The state of U/D may be changed while CS remains LOW. This

allows the host system to enable the device and then move the

wiper up and down until the proper trim is attained.

Mode Selection

CS

INC

U/D

L

H

L

L

H

X

H

X

X

L

L

X

L

H

L

L

MODE

Wiper up

Wiper down

Standby mode

Standby mode

Normal mode

Wiper Up (not recommended)

Wiper Down (not recommend-

ed)

FN8157 Rev 6.00

August 14, 2015

Page 3 of 12

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