APPLICATION NOTES A V A I L A B L E AN42 • AN44–50 • AN52 • AN53 • AN71 • AN73 Terminal X9314 Voltage ±5V, 32 Taps, Log Taper X9314 E2POT™ Nonvolatile Digital Potentiometer FEATURES DESCRIPTION • The Xicor X9314 is a solid state nonvolatile potentiometer and is ideal for digitally controlled resistance trimming. • • • • • Low Power CMOS —VCC = 3V to 5.5V —Active Current, 3mA Max —Standby Current, 500µA Max 31 Resistive Elements —Temperature Compensated —±20% End to End Resistance Range — –5V to +5V Range 32 Wiper Tap Points —Wiper Positioned via Three-Wire Interface —Similar to TTL Up/Down Counter —Wiper Position Stored in Nonvolatile Memory and Recalled on Power-Up 100 Year Wiper Position Data Retention X9314W = 10KΩ Packages —8-Lead MSOP —8-Lead PDIP —8-Lead SOIC 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. All Xicor nonvolatile Digitally Controlled Potentiometers are designed and tested for applications requiring extended endurance and data retention. FUNCTIONAL DIAGRAM U/D INC CS 5-BIT UP/DOWN COUNTER 31 VH 30 29 5-BIT NONVOLATILE MEMORY ONE OF THIRTYTWO DECODER 28 TRANSFER GATES RESISTOR ARRAY 2 VCC GND STORE AND RECALL CONTROL CIRCUITRY 1 0 VL VW 6427 FHD F01 E2POT™ is a trademark of Xicor, Inc. ©Xicor, Inc. 1994, 1995, 1996 Patents Pending 6427-1.7 6/12/96 T3/C1/D8 NS 1 Characteristics subject to change without notice X9314 PIN DESCRIPTIONS PIN CONFIGURATION VH and VL 8-LEAD DIP/SOIC The high (VH) and low (VL) 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 and 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. INC 1 8 VCC U/D 2 7 CS VH 3 6 VL VSS 4 5 VW X9314 8-LEAD MSOP VW Vw 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 40Ω. VH VSS 1 8 U/D 2 7 INC VW 3 6 VCC VL 4 5 CS X9314 6427 ILL F02.2 Up/Down (U/D) PIN NAMES The U/D input controls the direction of the wiper movement and whether the counter is incremented or decremented. Symbol Description VH VW VL VSS VCC U/D INC CS High Terminal Wiper Terminal Low Terminal Ground Supply Voltage Up/Down Input Increment Input Chip Select Input 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 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. 6427 PGM T01 Typical Attenuation Characteristics (dB) ATTENUATION (dB) 0 -20 -40 -43.5 -60 31 28 24 20 16 TAP POSITION 2 12 8 4 0 6427 ILL F07 X9314 DEVICE OPERATION Operation Notes 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 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 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 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 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 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. 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. RTOTAL with VCC Removed The end to end resistance of the array will fluctuate once VCC is removed. 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 N/A Changing: State Not Known Center Line is High Impedance 3 X9314 ABSOLUTE MAXIMUM RATINGS* Temperature under Bias .................. –65°C to +135°C Storage Temperature ....................... –65°C to +150°C Voltage on CS, INC, U/D and VCC with Respect to VSS ............................... –1V to +7V Voltage on VH and VL Referenced to VSS ................................. –8V to +8V ∆V = |VH–VL| X9314W .......................................................... 10V Lead Temperature (Soldering 10 seconds)....... 300°C Wiper Current ..................................................... ±1mA *COMMENT Stresses above those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress rating only and 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. ANALOG CHARACTERISTICS Electrical Characteristics Temperature Coefficient End-to-End Resistance Tolerance ..................... ±20% Power Rating at 25°C X9314W ...................................................... 10mW Wiper Current ............................................ ±1mA Max. Typical Wiper Resistance ......................... 40Ω at 1mA Typical Noise .......................... < –120dB/ Hz Ref: 1V (–40°C to +85°C) X9314W ..................................... +600 ppm/°C Typical Ratiometric Temperature Coefficient ............ ±20 ppm Wiper Adjustability Unlimited Wiper Adjustment (Non-Store operation) Wiper Position Store Operations ............. 100,000 Data Changes Relative Variation Relative variation is a measure of the error in step size between taps = log(Vw(n)) – log(Vw(n-1)) = 0.07±0.003 for tap n = 2 – 31 Physical Characteristics Marking Includes Manufacturer’s Trademark Resistance Value or Code Date Code Typical Electrical Taper 100.0% 90.0% 80.0% 60.0% 50.0% 40.0% 30.0% 20.0% 10.0% Tap 4 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 9 10 8 7 6 5 4 3 2 1 0.0% 0 % Total Resistance 70.0% 6427 ILL F06 X9314 RECOMMENDED OPERATING CONDITIONS Temperature Min. Max. Supply Voltage Limits Commercial Industrial Military 0°C –40°C –55°C +70°C +85°C +125°C X9314 X9314-3 5V ±10% 3V to 5.5V 6427 PGM T04.1 6427 PGM T03.1 D.C. OPERATING CHARACTERISTICS (Over recommended operating conditions unless otherwise specified.) Limits Symbol ICC Parameter VCC Active Current Min. Typ.(4) 1 Max. 3 Units mA ISB Standby Supply Current 500 µA ILI CS, INC, U/D Input Leakage Current CS, INC, U/D Input HIGH Voltage CS, INC, U/D Input LOW Voltage Wiper Resistance VH Terminal Voltage VL Terminal Voltage CS, INC, U/D Input Capacitance ±10 µA 2 VCC + 1 V –1 0.8 V 100 +5 +5 10 Ω V V pF VIH VIL RW VVH VVL CIN(5) 40 –5 –5 Test Conditions CS = VIL, U/D = VIL or VIH and INC = 0.4V/2.4V @ max. tCYC CS = VCC – 0.3V, U/D and INC = VSS or VCC – 0.3V VIN = VSS to VCC Max. Wiper Current ±1mA VCC = 5V, VIN = VSS, TA = 25°C, f = 1MHz 6427 PGM T05.3 STANDARD PARTS Part Number Maximum Resistance Wiper Increments Minimum Resistance X9314W 10KΩ Log Taper 40Ω 6427 PGM T08.1 Notes: (4) Typical values are for TA = 25°C and nominal supply voltage. (5) This parameter is periodically sampled and not 100% tested. Test Circuit #1 Test Circuit #2 VH VH TEST POINT VW TEST POINT VW VL VL 6427 ILL F04 FORCE CURRENT 6427 ILL F05 5 X9314 A.C. CONDITIONS OF TEST MODE SELECTION Input Pulse Levels Input Rise and Fall Times Input Reference Levels CS 0V to 3V 10ns 1.5V INC U/D Mode H X L H L X X X Wiper Up Wiper Down Store Wiper Position Standby No Store, Return to Standby L L 6427 PGM T05.1 H 6427 PGM T06 A.C. OPERATING CHARACTERISTICS (Over recommended operating conditions unless otherwise specified) Limits Symbol tCl tlD tDI tlL tlH tlC tCPH tIW tCYC tR, tF(7) tPU(7) tR VCC Parameter CS to INC Setup INC HIGH to U/D Change U/D to INC Setup INC LOW Period INC HIGH Period INC Inactive to CS Inactive CS Deselect Time INC to Vw Change INC Cycle Time INC Input Rise and Fall Time Power up to Wiper Stable VCC Power-up Rate Min. 100 100 2.9 1 1 1 20 Typ.(6) Max. 100 500 4 500 500 50 0.2 Units ns ns µs µs µs µs ms µs µs µs µs mV/µs 6427 PGM T07.3 A.C. Timing CS tCYC tCI tIL tIH tIC tCPH 90% 90% 10% INC tID tDI tF tR U/D tIW VW (8) MI 6427 FHD F03 Notes: (6) Typical values are for TA = 25°C and nominal supply voltage. (7) This parameter is periodically sampled and not 100% tested. (8) MI in the A.C. timing diagram refers to the minimum incremental change in the VW output due to a change in the wiper position. 6 X9314 PACKAGING INFORMATION 8-LEAD MINIATURE SMALL OUTLINE GULL WING PACKAGE TYPE M 0.118 ± 0.002 (3.00 ± 0.05) 0.012 + 0.006 / -0.002 (0.30 + 0.15 / -0.05) 0.0256 (0.65) TYP R 0.014 (0.36) 0.118 ± 0.002 (3.00 ± 0.05) 0.030 (0.76) 0.0216 (0.55) 0.036 (0.91) 0.032 (0.81) 0.040 ± 0.002 (1.02 ± 0.05) 0.007 (0.18) 0.005 (0.13) 7° TYP 0.008 (0.20) 0.004 (0.10) 0.150 (3.81) REF. 0.193 (4.90) REF. NOTE: 1. ALL DIMENSIONS IN INCHES AND (MILLIMETERS) 3003 ILL 01 7 X9314 PACKAGING INFORMATION 8-LEAD PLASTIC DUAL IN-LINE PACKAGE TYPE P 0.430 (10.92) 0.360 (9.14) 0.260 (6.60) 0.240 (6.10) PIN 1 INDEX PIN 1 0.300 (7.62) REF. HALF SHOULDER WIDTH ON ALL END PINS OPTIONAL 0.145 (3.68) 0.128 (3.25) SEATING PLANE 0.025 (0.64) 0.015 (0.38) 0.065 (1.65) 0.045 (1.14) 0.150 (3.81) 0.125 (3.18) 0.020 (0.51) 0.016 (0.41) 0.110 (2.79) 0.090 (2.29) 0.015 (0.38) MAX. 0.060 (1.52) 0.020 (0.51) 0.325 (8.25) 0.300 (7.62) 0° 15° TYP. 0.010 (0.25) NOTE: 1. ALL DIMENSIONS IN INCHES (IN PARENTHESES IN MILLIMETERS) 2. PACKAGE DIMENSIONS EXCLUDE MOLDING FLASH 3926 FHD F01 8 X9314 PACKAGING INFORMATION 8-LEAD PLASTIC SMALL OUTLINE GULL WING PACKAGE TYPE S 0.150 (3.80) 0.158 (4.00) 0.228 (5.80) 0.244 (6.20) PIN 1 INDEX PIN 1 0.014 (0.35) 0.019 (0.49) 0.188 (4.78) 0.197 (5.00) (4X) 7° 0.053 (1.35) 0.069 (1.75) 0.004 (0.19) 0.010 (0.25) 0.050 (1.27) 0.010 (0.25) X 45° 0.020 (0.50) 0.050" TYPICAL 0.050" TYPICAL 0° – 8° 0.0075 (0.19) 0.010 (0.25) 0.250" 0.016 (0.410) 0.037 (0.937) 0.030" TYPICAL 8 PLACES FOOTPRINT NOTE: ALL DIMENSIONS IN INCHES (IN PARENTHESES IN MILLIMETERS) 3926 FHD F22.1 9 X9314 ORDERING INFORMATION X9314 E2POT 10K Ohms, Log Taper X9314W X X X VCC Range Blank = VCC = 5V ±10% 3 = VCC = 3V to 5.5V Temperature Range Blank = 0°C to +70°C I = –40°C to +85°C M = –55°C to +125°C Package M = 8-Lead MSOP P = 8-Lead Plastic DIP S = 8-Lead SOIC End to End Resistance W = 10KΩ Part Mark Convention X9314W X P = 8-Lead Plastic DIP Blank = 8-Lead SOIC (Date Code) X Blank = 5V ±10%, 0°C to 70°C I = 5V ±10%, -40°C to +85°C D = 3V to 5.5V, 0°C to 70°C E = 3V to 5.5V, -40°C to +85°C LIMITED WARRANTY Devices sold by Xicor, Inc. are covered by the warranty and patent indemnification provisions appearing in its Terms of Sale only. Xicor, Inc. makes no warranty, express, statutory, implied, or by description regarding the information set forth herein or regarding the freedom of the described devices from patent infringement. Xicor, Inc. makes no warranty of merchantability or fitness for any purpose. Xicor, Inc. reserves the right to discontinue production and change specifications and prices at any time and without notice. Xicor, Inc. assumes no responsibility for the use of any circuitry other than circuitry embodied in a Xicor, Inc. product. No other circuits, patents, licenses are implied. U.S. PATENTS Xicor products are covered by one or more of the following U.S. Patents: 4,263,664; 4,274,012; 4,300,212; 4,314,265; 4,326,134; 4,393,481; 4,404,475; 4,450,402; 4,486,769; 4,488,060; 4,520,461; 4,533,846; 4,599,706; 4,617,652; 4,668,932; 4,752,912; 4,829, 482; 4,874, 967; 4,883, 976. Foreign patents and additional patents pending. LIFE RELATED POLICY In situations where semiconductor component failure may endanger life, system designers using this product should design the system with appropriate error detection and correction, redundancy and back-up features to prevent such an occurence. Xicor's products are not authorized for use in critical components in life support devices or systems. 1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, and whose failure to perform, when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury to the user. 2. A critical component is any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness. 10