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Details, datasheet, quote on part number:X9015
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| Part: | X9015 |
| Category: | Analog & Mixed-Signal Processing => Potentiometers => Digital Potentiometers |
| Description: | Single 32 Tap Volatile |
| Company: | Xicor, Inc. |
| Datasheet: | Download X9015 datasheet File size : 83 kB |
| Request For quote: | Find where to buy X9015
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Datasheet text preview:
APPLICATION NOTES AVAILABLE
AN99 · AN115 · AN120 · AN124 · AN133 · AN134
Low Noise, Low Power, Volatile
X9015
Single Digitally Controlled (XDCPTM) Potentiometer
FEATURES · · · · · · · 32 taps Three-wire up/down serial interface VCC = 2.7V5V Operating ICC = 50µA max. Standby current = 1µA max. RTOTAL = 10K, 50K, 100K Packages SOIC-8, MSOP-8 DESCRIPTION The Xicor X9015 is a 32 tap potentiometer that is volatile. The device consists of a string of 31 resistors that can be programmed to connect the RW/VW wiper output with any of the nodes between the connecting resistors. The connection point of the wiper is determined by information communicated to the device on the 3-wire port. The 3-wire port changes the tap position by a falling edge on the increment pin. The direction the wiper moves is determined by the state of the up/ down pin. The wiper position at power up is Tap #15. The X9015 can be used in a wide variety of applications that require a digitally controlled variable resistor to set analog values.
BLOCK DIAGRAM
VCC (Supply Voltage)
U/D INC CS
5-Bit Up/Down Counter
31 30 29 One 28 of Thirty Two Decoder 2
RH/VH
Up/Down (U/D) Increment (INC) Device Select (CS) Control
RH/VH RW/VW RL/VL VSS (Ground) General VCC VSS Control Circuitry
Transfer Gates
Resistor Array
1 0 RL/VL RW/VW Detailed
XDCP is a trademark of Xicor, Inc. REV 1.1.1 7/19/01
www.xicor.com
Characteristics subject to change without notice.
1 of 12
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 CONFIGURATION
SOIC/MSOP INC U/D RH/VH VSS 1 2 3 4 X9015 8 7 6 5 VCC CS RL/VL RW/VW
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.
REV 1.1.1 7/19/01
www.xicor.com
Characteristics subject to change without notice.
2 of 12
X9015
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
L L * L H L
SYMBOL TABLE
WAVEFORM
INPUTS Must be steady May change from Low to High May change from High to Low Don't Care: Changes Allowed N/A
OUTPUTS Will be steady Will change from Low to High Will change from High to Low Changing: State Not Known Center Line is High Impedance
INC
U/D
H L X X Wiper up
Mode
Wiper down Standby mode Normal mode
REV 1.1.1 7/19/01
www.xicor.com
Characteristics subject to change without notice.
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