X9312 Terminal Voltage 0V to +15V, 100 Taps Data Sheet March 15, 2005 FN8176.0 DESCRIPTION Digitally Controlled Potentiometer (XDCP) The Intersil X9312 is a digitally controlled potentiometer (XDCP). The device consists of a FEATURES resistor array, wiper switches, a control section, and nonvolatile memory. The wiper position is controlled Solid-state potentiometer by a 3-wire interface. 3-wire serial interface Terminal voltage, 0 to +15V The potentiometer is implemented by a resistor array 100 wiper tap points composed of 99 resistive elements and a wiper Wiper position stored in nonvolatile memory switching network. Between each element and at and recalled on power-up either end are tap points accessible to the wiper 99 resistive elements terminal. The position of the wiper element is Temperature compensated controlled by the CS, U/D, and INC inputs. The End to end resistance range 20% position of the wiper can be stored in nonvolatile Low power CMOS memory and then be recalled upon a subsequent V = 5V CC power-up operation. Active current, 3mA max. Standby current, 1mA max. The device can be used as a three-terminal High reliability potentiometer or as a two-terminal variable resistor in Endurance, 100,000 data changes per bit a wide variety of applications including: Register data retention, 100 years control R values = 10k, 50k, and 100k TOTAL parameter adjustments Packages 8-lead SOIC and DIP signal processing BLOCK DIAGRAM U/D 7-Bit R /V 99 H H INC Up/Down V (Supply Voltage) CC Counter CS 98 97 R /V Up/Down H H (U/D) 7-Bit 96 One Control Nonvolatile Increment of R /V and W W Memory (INC) One Memory Transfer Resistor Hundred Gates Device Select Array Decoder (CS) R /V L L 2 Store and V (Ground) 1 SS Recall V CC Control V General SS Circuitry 0 R /V L L R /V W W Detailed CAUTION: These devices are sensitive to electrostatic discharge follow proper IC Handling Procedures. 1 1-888-INTERSIL or 1-888-352-6832 Intersil (and design) is a registered trademark of Intersil Americas Inc. XDCP is a trademark of Intersil Americas Inc. Copyright Intersil Americas Inc. 2005. All Rights Reserved All other trademarks mentioned are the property of their respective owners. NOT RECOMMENDED FOR NEW DESIGNS NO RECOMMENDED REPLACEMENT contact our Technical Support Center at 1-888-INTERSIL or www.intersil.com/tscX9312 PIN DESCRIPTIONS PIN NAMES R /V and R /V H L Symbol Description H L The high (R /V ) and low (R /V ) terminals of the H L H L R /V High terminal H H X9312 are equivalent to the fixed terminals of a R /V Wiper terminal W W mechanical potentiometer. The minimum voltage is 0V R /V Low terminal and the maximum is +15V. The terminology of R /V L L L L and R /V references the relative position of the V Ground H H SS terminal in relation to wiper movement direction V Supply voltage CC selected by the U/D input and not the voltage potential U/D Up/Down control input on the terminal. INC Increment control input R /V W W CS Chip select control input R /V is the wiper terminal and is equivalent to the w w movable terminal of a mechanical potentiometer. The PRINCIPLES OF OPERATION position of the wiper within the array is determined by the control inputs. The wiper terminal series resistance There are three sections of the X9312: the input is typically 40. control, counter and decode section the nonvolatile memory and the resistor array. The input control Up/Down (U/D) section operates just like an up/down counter. The The U/D input controls the direction of the wiper output of this counter is decoded to turn on a single movement and whether the counter is incriminated or electronic switch connecting a point on the resistor decremented. array to the wiper output. Under the proper conditions the contents of the counter can be stored in Increment (INC) nonvolatile memory and retained for future use. The The INC input is negative-edge triggered. Toggling resistor array is comprised of 99 individual resistors INC will move the wiper and either increment or connected in series. At either end of the array and decrement the counter in the direction indicated by the between each resistor is an electronic switch that logic level on the U/D input. transfers the potential at that point to the wiper. Chip Select (CS) The wiper, when at either fixed terminal, acts like its The device is selected when the CS input is LOW. The mechanical equivalent and does not move beyond the current counter value is stored in nonvolatile memory last position. That is, the counter does not wrap when CS is returned HIGH while the INC input is also around when clocked to either extreme. HIGH. After the store operation is complete the X9312 The electronic switches on the device operate in a will be placed in the low power standby mode until the make before break mode when the wiper changes device is selected once again. tap positions. If the wiper is moved several positions, multiple taps are connected to the wiper for t (INC to PIN CONFIGURATION IW V change). The R value for the device can W TOTAL temporarily be reduced by a significant amount if the DIP/SOIC wiper is moved several positions. INC V 1 8 When the device is powered-down, the last wiper CC position stored will be maintained in the nonvolatile U/D CS 2 7 X9312 memory. When power is restored, the contents of the R /V R /V 3 6 L L H H memory are recalled and the wiper is set to the value V R /V SS 4 5 W W last stored. FN8176.0 2 March 15, 2005