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Details, datasheet, quote on part number:X9314WMI
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| Part: | X9314WMI |
| Category: | Analog & Mixed-Signal Processing => Potentiometers => Digital Potentiometers |
| Description: | Single 32 Tap Xdcp, 2-wire Increment/decrement Interface, Single Supply, Log Taper |
| Company: | Xicor, Inc. |
| Datasheet: | Download X9314WMI datasheet File size : 300 kB |
| Request For quote: | Find where to buy X9314WMI
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Datasheet text preview:
APPLICATION NOTE AVAILABLE
AN42 · AN4450 · AN52 · AN53 · AN71 · AN73 · AN99 · AN115 · AN120 · AN124 · AN134
Terminal Voltages ±5V, 32 Taps, Log Taper
X9314
Single Digitally Controlled Potentiometer (XDCPTM)
FEATURES · · · · · · Solid State Potentiometer 32 Taps 10K End to End Resistance Three-Wire Up/Down Serial Interface Wiper Resistance, 40 Typical Nonvolatile Storage and Recall on Power Up of Wiper Position Standby Current < 500µA Max (Total Package) · VCC = 3V to 5.5V Operation · 100 Year Data Retention · Offered in MSOP, SOIC Packages DESCRIPTION The Xicor X9314 is a solid state nonvolatile potentiometer and is ideal for digitally controlled resistance trimming. The X9314 is a resistor array composed of 31 resistive elements. Between each element and at either end are tap points accessible to the wiper element. The position of the wiper element is controlled by the CS, U/D, and INC inputs. The position of the wiper can be stored in nonvolatile memory and then be recalled upon a subsequent power-up operation. The XDCP can be used as a three-terminal potentiometer or as a two-terminal variable resistor in a wide variety of applications including control, parameter adjustments, and signal processing. BLOCK DIAGRAM
U/D INC CS 5-Bit Up/Down Counter 31 30 29 28 One of Thirty-Two Decoder
VH/RH
5-Bit Nonvolatile Memory
Transfer Gates 2
Resistor Array
Store and Recall Control Circuitry VCC VSS
1 0 VL/RL VW/RW
XDCP is a trademark of Xicor, Inc. REV 1.1 11/10/00
www.xicor.com
Characteristics subject to change without notice.
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X9314
PIN DESCRIPTIONS VH/RH and VL/RL The high (VH/RH) and low (VL/RL) terminals of the X9314 are equivalent to the fixed terminals of a mechanical potentiometer. The minimum voltage is 5V and the maximum is +5V. It should be noted that the terminology of VL/RL and VH/RH 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. VW/RW VW/RW is the wiper terminal, 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 40. Up/Down (U/D) The U/D input controls the direction of the wiper movement and whether the counter 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. The current counter value is stored in nonvolatile memory when CS is returned HIGH while the INC input is also Typical Attenuation Characteristics (dB)
0
HIGH. After the store operation is complete the X9314 will be placed in the low power standby mode until the device is selected once again. PIN CONFIGURATION
8-Lead DIP/SOIC INC U/D VH/RH VSS 1 2 3 4 X9314 8 7 6 5 VCC CS VL/RL VW/RW
8-Lead MSOP VH/RH VSS VW/RW VL/RL 1 2 3 4 X9314 8 7 6 5 U/D INC VCC CS
PIN NAMES Symbol
VH/RH VW/RW VL/RL VSS VCC U/D INC CS
Description
High Terminal Wiper Terminal Low Terminal Ground Supply Voltage Up/Down Input Increment Input Chip Select Input
Attenuation (dB)
-20
-40 -43.5
-60
31
28
24
20
16 Tap Position
12
8
4
0
REV 1.1 11/10/00
www.xicor.com
Characteristics subject to change without notice.
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X9314
PRINCIPLES OF OPERATION There are three sections of the X9314: the input control, counter and decode section; the nonvolatile memory; 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. Under the proper conditions the contents of the counter can be stored in nonvolatile memory and retained for future use. The resistor array is comprised of 31 individual resistors connected in series. At either end of the array and between each resistor is an electronic switch that transfers the potential at that point to the wiper. The INC, U/D and CS inputs control the movement of the wiper along the resistor array. With CS set LOW the X9314 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 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 value of the counter is stored in nonvolatile memory whenever CS transistions HIGH while the INC input is also HIGH. When the X9314 is powered-down, the last counter position stored will be maintained in the nonvolatile memory. When power is restored, the contents of the memory are recalled and the counter is reset to the value last stored. Operation Notes The system may select the X9314, move the wiper and deselect the device without having to store the latest wiper position in nonvolatile memory. The wiper movement is performed as described above; once the new position is reached, the system would keep the INC LOW while taking CS HIGH. The new wiper position would be maintained until changed by the system or until a power-up/down cycle recalled the previously stored data. This would allow the system to always power-up to a preset value stored in nonvolatile memory; then during system operation minor adjustments could be made. The adjustments might be based on user preference, system parameter changes due to temperature drift, etc... The state of U/D may be changed while CS remains LOW. This allows the host system to enable the X9314 and then move the wiper up and down until the proper trim is attained. tIW/RTOTAL The electronic switches on the X9314 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. 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
REV 1.1 11/10/00
www.xicor.com
Characteristics subject to change without notice.
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