X93254 ® Data Sheet March 1, 2005 Dual Digitally Controlled Potentiometers (XDCPs™) FN8186.0 DESCRIPTION The Intersil X93254 is a dual digitally controlled potentiometer (XDCP). The device consists of two resistor arrays, wiper switches, a control section, and nonvolatile memory. The wiper positions are controlled by individual Up/Down interfaces. FEATURES • Dual solid-state potentiometers • Independent Up/Down interfaces • 32 wiper tap points per potentiometer —Wiper position stored in nonvolatile memory and recalled on power-up • 31 resistive elements per potentiometer —Temperature compensated —Maximum resistance tolerance of ± 30% —Terminal voltage, 0 to VCC • Low power CMOS —VCC = 3V±10% —Active current, 250µA max —Standby current, 1µA max • High reliability —Endurance 200,000 data changes per bit —Register data retention, 100 years • RTOTAL value = 50kΩ • 14-lead TSSOP package A potentiometer is implemented by a resistor array composed of 31 resistive elements and a wiper switching network. The position of each wiper element is controlled by a set of independent 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. Each potentiometer is connected as a two-terminal variable resistor and can be used in a wide variety of applications including: – Bias and Gain control – LCD Contrast Adjustment BLOCK DIAGRAM VCC (Supply Voltage) RH1 30K 30K Up/Down (U/D1) Increment (INC1) Control and Memory RL1 RH2 Device Select (CS1) Up/Down (U/D2) Increment (INC2) Control and Memory RL2 Device Select (CS2) VSS (Ground) 1 CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. 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. X93254 PIN CONFIGURATION TSSOP DNC* 1 RL1 2 X93254 14 RH1 13 U/D1 12 INC1 VCC CS1 3 INC2 U/D2 4 5 11 10 RH2 6 9 CS2 RL2 VSS 7 8 DNC* *Do not connect. X93254 ORDERING CODES Ordering Number RTOTAL Package Temperature Range X93254UV14I-3 50kΩ 14-lead TSSOP package -40°C to +85°C PIN DESCRIPTIONS TSSOP Symbol Description 1 DNC Do Not Connect. 2 RL1 Low Terminal 1. 3 CS1 Chip Select 1. 4 INC2 Increment 2. 5 U/D2 Up/Down 2. 6 RH2 High Terminal 2. 7 VSS Ground. 8 DNC Do Not Connect. 9 RL2 Low Terminal 2. 10 CS2 Chip Select 2. 11 VCC Supply Voltage. 12 INC1 Increment 1. 13 U/D1 Up/Down 1. 14 RH1 High Terminal 1. 2 FN8186.0 March 1, 2005 X93254 ABSOLUTE MAXIMUM RATINGS COMMENT Temperature under bias .................... -65°C to +135°C Storage temperature ......................... -65°C to +150°C Voltage on CS, INC, U/D, RH, RL and VCC with respect to VSS .............................. -1V to +6.5V Lead temperature (soldering 10 seconds) ......... 300°C Maximum reflow temperature (40 seconds) ...... 240°C Maximum resistor current ..................................... 2mA Stresses above those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress rating only; the functional operation of the device (at these or any other conditions above those listed in the operational sections of this specification) is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. RECOMMENDED OPERATING CONDITIONS Temperature Industrial Min. -40°C Max. +85°C Supply Voltage (VCC) X93254 Limits 3V ± 10%(7) POTENTIOMETER CHARACTERISTICS (Over recommended operating conditions unless otherwise stated.) Limits Symbol RTOT VR Parameter End to end resistance RH, RL terminal voltages Min. Typ. Max. Unit 37.5 50 62.5 kΩ (5) VCC V (5) 1 mW(6) RTOTAL = 50kΩ(5) dBV(6) Ref: 1kHz(5) 0 Power rating Noise -120 RW Wiper Resistance IW Wiper Current Resolution Relative linearity(2) RTOTAL temperature coefficient CH/CL/CW 1000 Ω (5) (6) 0.6 mA (5) (6) 3 Absolute linearity(1) Potentiometer capacitances ±35 10/10/25 Test Conditions/Notes % (5) ±1 MI(3) VH(n)(actual) - VH(n)(expected)(5) ±0.5 MI(3) VH(n+1) - [VH(n)+MI(5) ppm/°C (5) (6) pF See circuit #2(5) Notes: (1) Absolute linearity is utilized to determine actual wiper voltage versus expected voltage = (VH(n)(actual) - VH(n)(expected)) = ±1 Ml Maximum. n = 1 .. 29 only (2) Relative linearity is a measure of the error in step size between taps = VH(n+1) - [VH(n) + Ml] = ±0.5 Ml, n = 1 .. 29 only. (3) 1 Ml = Minimum Increment = RTOT/31. (4) Typical values are for TA = 25°C and nominal supply voltage. (5) This parameter only applies to a single potentiometer. (6) This parameter is guaranteed by characterization. (7) When performing multiple write operations, VCC must not decrease by more than 150mV from its initial value. 3 FN8186.0 March 1, 2005 X93254 D.C. OPERATING CHARACTERISTICS (Over recommended operating conditions unless otherwise specified.) Limits Typ.(4) Max. Unit Test Conditions 50 250 µA CS = VIL, U/D = VIL or VIH and INC = 0.4V @ max. tCY(5) 600 µA CS = VIH, U/D = VIL or VIH and INC = VIH @ max. tWR(5) Standby supply current 1 µA CS = VCC – 0.3V, U/D and INC = VSS or VCC - 0.3V ILI CS1 or CS2 ±1 µA VIN = VCC (5) ILI CS1 or CS2 150 µA VCC = 3V, CS = 0(5) ILI INC1, INC2, U/D1, U/D2 input leakage current ±1 µA VIN = VSS to VCC(5) VIH CS1, CS2, INC1, INC2, U/D1, U/D2 input HIGH voltage VCC x 0.7 VCC + 0.5 V (5) VIL CS1, CS2, INC1, INC2, U/D1, U/D2 input HIGH voltage -0.5 VCC x 0.1 V (5) CIN CS1, CS2, INC1, INC2, U/D1, U/D2 input capacitance 10 pF VCC = 3V, VIN = VSS, TA = 25°C, f = 1MHz(6) Symbol Parameter Min. ICC1 VCC active current (Increment) per DCP ICC2 VCC active current (Store) (EEPROM Store) per DCP ISB 60 100 ENDURANCE AND DATA RETENTION Parameter Min. Unit Minimum endurance 200,000 Data changes per bit Data retention 100 Years Test Circuit #1 Circuit #2 SPICE Macro Model Test Point VH/RH RTOTAL RH CH CW CL RL 10pF 25pF 10pF VL A.C. CONDITIONS OF TEST Input pulse levels 0V to 3V Input rise and fall times 10ns Input reference levels 1.5V 4 FN8186.0 March 1, 2005 X93254 A.C. OPERATING CHARACTERISTICS (Over recommended operating conditions unless otherwise specified. In the table, CS, INC, U/D, RH and RL are used to refer to either CS1 or CS2, etc.) Limits Symbol Parameter Typ.(6) Min. Max. Unit tCl CS to INC setup 100 ns tlD INC HIGH to U/D change 100 ns tDI U/D to INC setup 100 ns tlL INC LOW period 1 µs tlH INC HIGH period 1 µs tlC INC Inactive to CS inactive 1 µs tCPH CS Deselect time (NO STORE) 250 ns tCPH CS Deselect time (STORE) 10 ms tCYC INC cycle time 2 µs tR, tF(6) tR VCC(6) tWR INC input rise and fall time VCC power-up rate 1 Store cycle 5 500 µs 10,000 V/ms 10 ms POWER-UP AND DOWN REQUIREMENTS There are no restrictions on the power-up or power-down conditions of VCC and the voltages applied to the potentiometer pins provided that VCC is always more positive than or equal to VH and VL, i.e., VCC ≥ VH,VL. The VCC ramp rate spec is always in effect. A.C. TIMING (In the diagram, CS, INC, U/D, RH and RL are used to refer to either CS1 or CS2, etc.) CS tCYC tCI tIL tIH tIC (Store) tCPH 90% 90% 10% INC tID tDI tF tR U/D 5 FN8186.0 March 1, 2005 X93254 PIN DESCRIPTIONS (In the text, CS, INC, U/D, RH and RL are used to refer to either CS1 or CS2, etc. Note: These signals can be applied independently or at the same time.) RH and RL The RH and RL pins of the X93254 are equivalent to the fixed terminals of a mechanical potentiometer. The minimum voltage is VSS and the maximum is VCC. The terminology of RH and RL references the relative position of the terminal in relation to wiper movement direction selected by the U/D input per potentiometer. Up/Down (U/D) The U/D input controls the direction of a single potentiometer’s 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 corresponding potentiometer’s counter in the direction indicated by the logic level on the corresponding potentiometer’s U/D input. Chip Select (CS) A potentiometer is selected when the corresponding CS input is LOW. Its current counter value is stored in nonvolatile memory when the corresponding CS is returned HIGH while the corresponding INC input is also HIGH. After the store operation is complete the affected potentiometer will be placed in the low power standby mode until the potentiometer is selected once again. PRINCIPLES OF OPERATION There are multiple sections for each potentiometer in the X93254: an input control, a counter and decode section; the nonvolatile memory; and a resistor array. Each 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. Each 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 connection at that point to the wiper. If the wiper is moved several positions, multiple taps are connected to the wiper for tIW (INC to VW change). The 2-terminal resistance value for the device can temporarily change by a significant amount if the wiper is moved several positions. When the device is powered-down, the last wiper position stored will be maintained in the nonvolatile memory for each potentiometer. When power is restored, the contents of the memory are recalled and each wiper is set to the value last stored. 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 potentiometer 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 value of the counter is stored in nonvolatile memory whenever each CS transitions HIGH while the INC input is also HIGH. In order to avoid an accidental store during power-up, each CS must go HIGH with VCC during initial power-up. When left open, each CS pin is internally pulled up to VCC by an internal 30K resistor. The system may select the X93254, move any wiper and deselect the device without having to store the latest wiper position in nonvolatile memory. After the wiper movement is performed as described above and once the new position is reached, the system must keep INC LOW while taking CS HIGH. The new wiper position will be maintained until changed by the system or until a power-up/down cycle recalled the previously stored data. In order to recall the stored position of the wiper on power-up, the CS pin must be held HIGH. This procedure allows 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, or other system trim requirements. Each 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. 6 FN8186.0 March 1, 2005 X93254 The state of U/D may be changed while CS remains LOW. This allows the host system to enable the device and then move each wiper up and down until the proper trim is attained. MODE SELECTION CS INC U/D Mode L H Wiper Up L L Wiper Down H X Store Wiper Position X X Standby Current L X No Store, Return to Standby L H Wiper Up (not recommended) L L Wiper Down (not recommended) H 7 SYMBOL TABLE WAVEFORM INPUTS OUTPUTS Must be steady Will be steady May change from Low to High Will change from Low to High May change from High to Low Will change from High to Low Don’t Care: Changes Allowed Changing: State Not Known N/A Center Line is High Impedance FN8186.0 March 1, 2005 X93254 APPLICATIONS INFORMATION Electronic digitally controlled (XDCP) potentiometers provide three powerful application advantages; (1) the variability and reliability of a solid-state potentiometer (2) the flexibility of computer-based digital controls, and (3) the retentivity of nonvolatile memory used for the storage of multiple potentiometer settings or data. VR I Two terminal variable resistor. Low Voltage High Impedance Instrumentation Amplifier 3.3V 10K + + 10K 50K U1A – 50K VIN – VOUT U1C 1/ 2 X93254 (R TOTAL) + 50K – U1B 10K + – 50K 50K 1+ 10K RTOTAL U1 = LT1467 Gain = 10K ) ( 50K Micro-Power LCD Contrast Control 3.3V 300K 240K 3.3V + 100K 100K VOUT = -3.88 1 + 50K + R ( 100K U1A – – U1B 100K VOUT = -2.75V to -11.6V U1 = LMC6042 + 50K ) TOTAL –12V 1/ 2 X93254 (R TOTAL) 8 FN8186.0 March 1, 2005 X93254 APPLICATIONS INFORMATION (Continued) Single Supply Variable Gain Amplifier 3.3V 3.3V 20K + 20K U1 VOUT – Gain = RTOTAL 10K U1 = LMC6042 VIN 10K 1/ 2 X93254 (RTOTAL) 9 FN8186.0 March 1, 2005 X93254 PACKAGING INFORMATION 14-Lead Plastic, TSSOP, Package Code V14 .025 (.65) BSC .169 (4.3) .252 (6.4) BSC .177 (4.5) .193 (4.9) .200 (5.1) .041 (1.05) .0075 (.19) .0118 (.30) .002 (.05) .006 (.15) .010 (.25) Gage Plane 0° - 8° Seating Plane .019 (.50) .029 (.75) Detail A (20X) .031 (.80) .041 (1.05) See Detail “A” NOTE: ALL DIMENSIONS IN INCHES (IN PARENTHESES IN MILLIMETERS) All Intersil U.S. products are manufactured, assembled and tested utilizing ISO9000 quality systems. Intersil Corporation’s quality certifications can be viewed at www.intersil.com/design/quality Intersil products are sold by description only. Intersil Corporation reserves the right to make changes in circuit design, software and/or specifications at any time without notice. Accordingly, the reader is cautioned to verify that data sheets are current before placing orders. Information furnished by Intersil is believed to be accurate and reliable. However, no responsibility is assumed by Intersil or its subsidiaries for its use; nor for any infringements of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Intersil or its subsidiaries. For information regarding Intersil Corporation and its products, see www.intersil.com 10 FN8186.0 March 1, 2005