KIT ATION EVALU E L B A IL AVA 19-3067; Rev 1; 2/06 32-Tap, Nonvolatile, Linear-Taper Digital Potentiometers in SOT23 The MAX5471/MAX5472/MAX5474/MAX5475 lineartaper digital potentiometers function as mechanical potentiometers, but replace the mechanics with a simple 3-wire up/down digital interface. These digital potentiometers feature nonvolatile memory (EEPROM) to return the wiper to its previously stored position upon power-up. The MAX5471/MAX5472 are 2-terminal, variable resistors in 6-pin SOT23 packages. The MAX5474/MAX5475 are 3-terminal potentiometers in 8-pin SOT23 packages. The MAX5471/MAX5474 have an end-to-end resistance of 50kΩ, and the MAX5472/MAX5475 have an endto-end resistance of 100kΩ. All of these devices have 32 wiper positions, a low ratiometric temperature coefficient (5ppm/°C), and all operate from a single +2.7V to +5.25V supply. Each device is guaranteed over the extended -40°C to +85°C temperature range. Applications Features ♦ Wiper Position Stored in Nonvolatile Memory and Recalled Upon Power-Up ♦ Tiny SOT23 Package ♦ 35ppm/°C End-to-End Resistance Temperature Coefficient ♦ 5ppm/°C Ratiometric Temperature Coefficient ♦ 32 Tap Positions ♦ Voltage-Divider or Variable-Resistor Potentiometer Configuration ♦ 50kΩ and 100kΩ End-to-End Resistance Values ♦ 1µA (max) Static Supply Current ♦ 2.7V to 5.25V Single-Supply Operation ♦ 200,000 Wiper Store Cycles ♦ 50-Year Wiper Data Retention Mechanical Potentiometer Replacement Ordering Information Liquid-Crystal-Display (LCD) Screen Adjustment Audio Volume Control PART Programmable Filters TEMP RANGE MAX5471EZT-T -40°C to +85°C 6 Thin SOT23-6 Z6-1 MAX5472EZT-T -40°C to +85°C 6 Thin SOT23-6 Z6-1 MAX5474EKA-T -40°C to +85°C 8 SOT23-8 K8S-3 MAX5475EKA-T -40°C to +85°C 8 SOT23-8 K8S-3 Pin Configurations Selector Guide PART TOP VIEW 6 VDD CS 1 GND 2 U/D 3 5 H MAX5471 MAX5472 4 INC VDD 2 7 W GND 3 6 H U/D 4 SOT23-6 8 L CS 1 MAX5474 MAX5475 PKG CODE PIN-PACKAGE END-TO-END RESISTANCE (kΩ) TOP MARK MAX5471EZT 50 ABQN MAX5472EZT 100 ABQM MAX5474EKA 50 AEIZ MAX5475EKA 100 AEIY 5 INC SOT23-8 ________________________________________________________________ Maxim Integrated Products For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com. 1 MAX5471/MAX5472/MAX5474/MAX5475 General Description MAX5471/MAX5472/MAX5474/MAX5475 32-Tap, Nonvolatile, Linear-Taper Digital Potentiometers in SOT23 ABSOLUTE MAXIMUM RATINGS VDD to GND ...........................................................-0.3V to +6.0V All Other Pins to GND .........-0.3V to the lower of (VDD + 0.3V) or +6.0V Maximum Continuous Current into H, L, and W MAX5471/MAX5474 .....................................................±1.3mA MAX5472/MAX5475 .....................................................±0.6mA Continuous Power Dissipation (TA = +70°C) 6-Pin SOT23 (derate 9.1mW/°C above +70°C)............727mW 8-Pin SOT23 (derate 8.9mW/°C above +70°C)............714mW Operating Temperature Range ...........................-40°C to +85°C Junction Temperature ......................................................+150°C Storage Temperature Range .............................-60°C to +150°C Lead Temperature (soldering, 10s) .................................+300°C Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. ELECTRICAL CHARACTERISTICS (VDD = +2.7V to +5.25V, VH = VDD, VL = GND, TA = -40°C to +85°C, unless otherwise noted. Typical values are at VDD = +5.0V, TA = +25°C, unless otherwise noted.) (Note 1) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS DC PERFORMANCE Resolution N End-to-End Resistance End-to-End Resistance Temperature Coefficient 32 37.5 50 62.5 MAX5472/MAX5475 75 100 125 TCR Ratiometric Resistance Temperature Coefficient Integral Nonlinearity Differential Nonlinearity INL DNL Full-Scale Error ppm/°C 5 ppm/°C Variable-resistor mode (Note 2) ±0.5 ±1.0 Voltage-divider mode (MAX5474/MAX5475) (Note 3) ±0.1 ±0.5 Variable-resistor mode (Note 2) ±0.5 ±1.0 Voltage-divider mode (MAX5474/MAX5475) (Note 3) ±0.1 ±0.5 MAX5474/MAX5475 RW MAX5474/MAX5475 (Note 4) kΩ 35 MAX5474/MAX5475 Zero-Scale Error Wiper Resistance Tap MAX5471/MAX5474 600 LSB LSB -0.5 LSB +0.5 LSB 1200 Ω DIGITAL INPUTS (CS, U/D, INC) (Note 5) Input High Voltage VIH Input Low Voltage VIL Input Current IIN VDD < 3.6V VDD ≥ 3.6V 0.7 x VDD V 2.4 VDD < 3.6V 0.3 x VDD VDD ≥ 3.6V 0.8 ±0.1 ±1 V µA DYNAMIC CHARACTERISTICS Wiper -3dB Bandwidth (Note 6) 2 MAX5471/MAX5474 400 MAX5472/MAX5475 200 _______________________________________________________________________________________ kHz 32-Tap, Nonvolatile, Linear-Taper Digital Potentiometers in SOT23 (VDD = +2.7V to +5.25V, VH = VDD, VL = GND, TA = -40°C to +85°C, unless otherwise noted. Typical values are at VDD = +5.0V, TA = +25°C, unless otherwise noted.) (Note 1) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS TIMING CHARACTERISTICS (Figure 1, Note 7) CS to INC Setup tCI 50 ns INC High to U/D Change tID 0 ns U/D to INC Setup tDI 100 ns INC Low Period tIL 50 ns INC High Period tIH 50 ns INC Cycle Time tCYC 100 ns INC Inactive to CS Inactive tIC 100 ns INC Active to CS Inactive tIK 100 ns CS Deselect Time (Store) tCPH Wiper Settling Time tIW Power-Up to Wiper Stable tPU Wiper Store Cycle 100 (Note 8) tWSC ns 1 µs 1 µs 12 ms NONVOLATILE MEMORY RELIABILITY Data Retention Endurance TA = +85°C 50 TA = +25°C 200,000 TA = +85°C 50,000 Year Store POWER SUPPLY Supply Voltage VDD Supply Current IDD Write to memory 2.70 Static Supply Current ISD TA = +25°C (Note 9) 0.35 5.25 V 400 µA 1 µA Note 1: All devices are production tested at TA = +25°C and are guaranteed by design and characterization for -40°C < TA < +85°C. Note 2: The DNL and INL are measured with the potentiometer configured as a variable resistor. For the 3-terminal potentiometers (MAX5474/MAX5475), H is unconnected and L = GND. At VDD = 5.25V, W is driven with a source current of 80µA for the 50kΩ configuration, and 40µA for the 100kΩ configuration. At VDD = 2.7V, the wiper terminal is driven with a source current of 40µA for the 50kΩ configuration, and 20µA for the 100kΩ configuration. Note 3: The DNL and INL are measured with the potentiometer configured as a voltage-divider with H = VDD and L = GND (MAX5474/MAX5475 only). The wiper terminal is unloaded. Note 4: The wiper resistance is the worst value measured by injecting the currents given in Note 2 into W with L = GND. RW = (VW - VH) / IW. Note 5: The device draws higher supply current when digital inputs are driven with voltages between 0.3V x VDD and 0.7 x VDD. Drive the digital inputs as close as possible to VDD or GND. (See the Typical Operating Characteristics for the Supply Current vs. Digital Input Voltage graph.) Note 6: Wiper at midscale with a 10pF load. Note 7: Digital timing is guaranteed by design and characterization, and is not production tested. Note 8: Wiper settling time is the worst-case 0% to 50% rise time measured between consecutive wiper positions. H = VDD, L = GND, and the wiper terminal is unloaded and measured with a 10pF oscilloscope probe (see the Typical Operating Characteristics for the Tap-to-Tap Switching Transient). Note 9: Digital inputs CS, U/D, and INC are connected to GND or VDD. See the Typical Operating Characteristics for the Static Supply Current vs. Temperature graph. _______________________________________________________________________________________ 3 MAX5471/MAX5472/MAX5474/MAX5475 ELECTRICAL CHARACTERISTICS (continued) Typical Operating Characteristics (VDD = 5.0V, TA = +25°C, unless otherwise noted.) STATIC SUPPLY CURRENT vs. TEMPERATURE 0.3 0.2 0.1 VDD = 5.0V 0.3 0.2 VDD = 3.0V 3.1 3.5 3.9 4.3 4.7 5.1 5.5 10 VDD = 3.0V 0.1 -40 -15 10 35 60 85 0 1 2 3 4 5 TEMPERATURE (°C) DIGITAL INPUT VOLTAGE (V) WIPER RESISTANCE vs. TAP POSITION (MAX5474) WIPER RESISTANCE vs. TAP POSITION (MAX5475) END-TO-END RESISTANCE % CHANGE vs. TEMPERATURE 400 VDD = 3.0V 350 VDD = 5.0V 250 500 450 VDD = 5.0V 400 350 300 250 200 200 10 15 20 25 30 0.05 0 100kΩ 100kΩ -0.05 -0.10 50kΩ -0.15 5 10 15 20 25 30 -40 -15 10 35 60 TAP POSITION TEMPERATURE (°C) W-TO-L RESISTANCE vs. TAP POSITION H-TO-GND RESISTANCE vs. TAP POSITION TAP-TO-TAP SWITCHING TRANSIENT MAX5475 60 40 MAX5474 20 0 MAX5471 toc08 MAX5471 toc07 80 100 80 15 20 TAP POSITION 25 30 INC 5V/div MAX5472 60 W 100mV/div 40 MAX5474 MAX5471 MAX5475 20 CL = 10pF VH = VDD TAP 16 TO TAP 15 0 10 85 MAX5471 toc09 TAP POSITION 100 5 50kΩ 0.10 -0.20 0 H-TO-GND RESISTANCE (kΩ) 5 0.15 MAX5471 toc06 VDD = 3.0V 0.20 END-TO-END RESISTANCE % CHANGE 450 300 550 WIPER RESISTANCE (Ω) 500 MAX5471 toc05 600 MAX5471 toc04 550 0 100 SUPPLY VOLTAGE (V) 600 0 VDD = 5.0V 1 0 2.7 WIPER RESISTANCE (Ω) 1000 0.1 0 4 10,000 MAX5471 toc03 0.4 SUPPLY CURRENT (μA) 0.4 DIGITAL INPUTS = GND OR VDD SUPPLY CURRENT (μA) DIGITAL INPUTS = GND OR VDD SUPPLY CURRENT (μA) 0.5 MAX5471 toc01 0.5 SUPPLY CURRENT vs. DIGITAL INPUT VOLTAGE MAX5471 toc02 SUPPLY CURRENT vs. SUPPLY VOLTAGE W-TO-L RESISTANCE (kΩ) MAX5471/MAX5472/MAX5474/MAX5475 32-Tap, Nonvolatile, Linear-Taper Digital Potentiometers in SOT23 0 5 10 15 20 25 30 400ns/div TAP POSITION _______________________________________________________________________________________ 32-Tap, Nonvolatile, Linear-Taper Digital Potentiometers in SOT23 WIPER TRANSIENT AT POWER-ON (MAX5475) VDD W W 1V/div 1V/div CL = 10pF TAP 16 VH = VDD CL = 10pF TAP 16 VH = VDD MAX5474 -6 -9 MAX5475 -12 -15 -18 1 1.0μs/div 1.0μs/div TAP = 16 CL = 10pF -3 WIPER RESPONSE (dB) 5V/div 5V/div MAX5471toc12 VDD WIPER RESPONSE vs. FREQUENCY 0 MAX5471 toc11 MAX5471 toc10 WIPER TRANSIENT AT POWER-ON (MAX5474) 10 100 1000 FREQUENCY (kHz) RESISTANCE INL vs. TAP POSITION (MAX5471) VARIABLE-RESISTOR MODE 0.1 0 -0.1 VARIABLE-RESISTOR MODE 0.2 RESISTANCE DNL 0.4 RESISTANCE INL 0.2 0.3 MAX5471 toc14 VARIABLE-RESISTOR MODE 0.3 0.2 0.1 0 -0.2 -0.1 -0.3 5 10 15 20 25 5 10 15 20 25 30 0 10 15 20 25 30 TAP POSITION TAP POSITION RESISTANCE INL vs. TAP POSITION (MAX5472) RESISTANCE DNL vs. TAP POSITION (MAX5474) RESISTANCE INL vs. TAP POSITION (MAX5474) 0.04 MAX5471 toc16 VARIABLE-RESISTOR MODE 0.4 VOLTAGE-DIVIDER MODE 0.04 0.03 VOLTAGE-DIVIDER MODE 0.03 0.3 0.2 0.1 0 -0.1 0.02 RESISTANCE INL RESISTANCE DNL 0.02 RESISTANCE INL 5 TAP POSITION 0.5 0.01 0 -0.01 5 10 15 20 TAP POSITION 25 30 0.01 0 -0.01 -0.02 -0.02 -0.03 -0.03 -0.04 0 -0.1 -0.3 0 30 0 MAX5471 toc18 0 0.1 -0.2 MAX5471 toc17 RESISTANCE DNL 0.5 MAX5471 toc13 0.3 RESISTANCE DNL vs. TAP POSITION (MAX5472) MAX5471 toc15 RESISTANCE DNL vs. TAP POSITION (MAX5471) -0.04 0 5 10 15 20 TAP POSITION 25 30 0 5 10 15 20 25 30 TAP POSITION _______________________________________________________________________________________ 5 MAX5471/MAX5472/MAX5474/MAX5475 Typical Operating Characteristics (continued) (VDD = 5.0V, TA = +25°C, unless otherwise noted.) Typical Operating Characteristics (continued) (VDD = 5.0V, TA = +25°C, unless otherwise noted.) RESISTANCE DNL vs. TAP POSITION (MAX5475) RESISTANCE INL vs. TAP POSITION (MAX5475) VOLTAGE-DIVIDER MODE 0.03 MAX5471 toc20 0.04 MAX5471 toc19 0.04 VOLTAGE-DIVIDER MODE 0.03 0.02 0.02 RESISTANCE INL RESISTANCE DNL MAX5471/MAX5472/MAX5474/MAX5475 32-Tap, Nonvolatile, Linear-Taper Digital Potentiometers in SOT23 0.01 0 -0.01 0.01 0 -0.01 -0.02 -0.02 -0.03 -0.03 -0.04 -0.04 0 5 10 15 20 25 30 0 5 TAP POSITION 10 15 20 25 30 TAP POSITION Pin Description PIN MAX5471/ MAX5472 MAX5474/ MAX5475 NAME 1 1 CS 2 3 GND Ground 3 4 U/D Up/Down Control Input. With U/D low, a high-to-low INC transition decrements the wiper position. With U/D high, a high-to-low INC transition increments the wiper position. 4 5 INC Wiper Increment Control Input. With CS low, the wiper position moves in the direction determined by the state of U/D on a high-to-low transition. 5 6 H 6 FUNCTION Chip-Select Input. Drive low to change wiper position (W) through INC and U/D. A low-tohigh transition with INC high stores the wiper position in nonvolatile memory. High Terminal of Resistor. The voltage at H can be greater than or less than the voltage at L. Current can flow into or out of H. 6 2 VDD — 7 W Wiper Terminal of Resistor Power Supply — 8 L Low Terminal of Resistor. The voltage at L can be greater than or less than the voltage at H. Current can flow into or out of L. _______________________________________________________________________________________ 32-Tap, Nonvolatile, Linear-Taper Digital Potentiometers in SOT23 WIPER POSITION NOT STORED CS tCYC tCI tIC tIH tIL tCPH tIK INC tID tDI tWSC U/D tIW VW NOTE: VW IS NOT A DIGITAL SIGNAL. IT REPRESENTS A WIPER TRANSITION. Figure 1. Digital Interface and Timing Diagram Detailed Description The MAX5471/MAX5472/MAX5474/MAX5475 contain a resistor array with 31 resistive elements (Figures 2 and 3). The MAX5471/MAX5474 have a total end-to-end resistance of 50kΩ, and the MAX5472/MAX5475 have an end-to-end resistance of 100kΩ. The MAX5471/ MAX5472 wiper is connected to the high terminal, and the low terminal is internally connected to ground, making the device a variable resistor. The MAX5474/ MAX5475 allow access to the high, low, and wiper terminals for a standard voltage-divider configuration. The wiper is moved among the 32 tap points through a simple 3-wire interface. Nonvolatile memory allows the wiper position to be stored and recalled to the same point upon power-up. Digital Interface Logic inputs CS, U/D, and INC control the wiper position and store it in nonvolatile memory (see the Truth Table). The chip-select (CS) input enables the serial interface when low and disables the interface when high. The position of the wiper is stored when CS transitions from low to high and INC is high (see the Storing Wiper Position section). With the serial interface active (CS low), a high-to-low (falling edge) transition on INC moves the wiper position by one resistive element in the direction determined by the state of U/D. If U/D is high, the wiper increments and it increases the resistance between W and L (it decreases the resistance between H and W). If U/D is low, the wiper decrements and it decreases the resistance between W and L (it increases the resistance between H and W). The direction of the wiper (state of U/D) can be changed at any time as long as the setup and hold times are met. Since the MAX5471/MAX5472 have the wiper internally connected to H, an increment command increases the resistance between H and GND, and a decrement command decreases the resistance between H and GND. The wiper performs a make-before-break transition, ensuring that there is never an open circuit during a transition from one resistor tap to another. When the wiper is at either end of the resistor array (max/min), additional transitions in the direction of the endpoint do not change the counter value (the wiper does not wrap around). Storing Wiper Position The position of the wiper is stored in nonvolatile memory whenever CS transitions low-to-high (rising edge) while INC is high. Upon power-up, the wiper returns to this stored position. By keeping INC low while taking CS high, the serial interface can be disabled and the potentiometer placed in standby without storing the latest wiper position. The factory-default wiper position is midscale. These devices can also be operated like a one-time programmable (OTP) device. Once the desired wiper position is trimmed and stored in nonvolatile memory, disable the serial interface by connecting CS to VDD, and INC to GND. The disabled interface places the device in standby and disallows any changes to the wiper position. In OTP mode, these devices become a fixed 3-terminal potentiometer or a 1-terminal resistor to GND with less than 1µA of supply current. _______________________________________________________________________________________ 7 MAX5471/MAX5472/MAX5474/MAX5475 WIPER POSITION STORED MAX5471/MAX5472/MAX5474/MAX5475 32-Tap, Nonvolatile, Linear-Taper Digital Potentiometers in SOT23 Applications Information Truth Table CS U/D INC W L L ↓ Decrement L H ↓ Increment L X ↑ No change H X X No change ↓ X X No change ↑ X L Position not stored ↑ X H Position stored ↓ = High-to-low transition. ↑ = Low-to-high transition. X = Don’t care. Standby Mode The MAX5471/MAX5472/MAX5474/MAX5475 are always in standby mode, except during the transition of a logic input or while the wiper position is being stored. When in standby mode, the static supply current is reduced to less than 1µA and the resistive terminals (H, W, and L) are unaffected. The MAX5471/MAX5472/MAX5474/MAX5475 are intended for circuits requiring digitally controlled adjustable resistance, such as LCD contrast control (where voltage biasing adjusts the display contrast), or programmable filters with adjustable gain and/or cutoff frequency. Positive LCD Bias Control Figures 4 and 5 show an application where the voltagedivider or variable resistor is used to make an adjustable, positive LCD-bias voltage. The op amp provides buffering and gain to the resistor-divider network made by the potentiometer (Figure 4) or to a fixed resistor and a variable resistor (Figure 5). Programmable Filter Figure 6 shows the configuration of a 1st-order programmable filter. The gain of the filter is adjusted by R2, and the cutoff frequency is adjusted by R3. Use the following equations to calculate the gain (G) and the 3dB cutoff frequency (fC): R1 R2 1 fC = 2π × R 3 × C G = 1+ H 6 H 5 S32 MAX5474 MAX5475 S32 MAX5471 MAX5472 VDD GND R31 VDD 6 GND S31 2 R30 CS CS INC U/D 1 4 3 UP/DOWN COUNTER S30 32-POSITION DECODER RW INC U/D R31 2 S31 3 R30 1 5 4 UP/DOWN COUNTER S30 32-POSITION DECODER S3 S3 NONVOLATILE MEMORY R2 NONVOLATILE MEMORY R2 S2 S2 R1 R1 S1 8 S1 L Figure 2. MAX5471/MAX5472 Functional Diagram 8 Figure 3. MAX5474/MAX5475 Functional Diagram _______________________________________________________________________________________ RW 7 W 32-Tap, Nonvolatile, Linear-Taper Digital Potentiometers in SOT23 VIN H 30V H VOUT W VOUT R3 MAX5474 MAX5475 R1 MAX5471 MAX5472 L H GND R2 Figure 4. Positive LCD Bias Control Using a Voltage-Divider MAX5471 MAX5472 GND 5V 30V Figure 6. Programmable Filter VOUT H MAX5471 MAX5472 GND Chip Information TRANSISTOR COUNT: 5031 PROCESS: BiCMOS Figure 5. Positive LCD Bias Control Using a Variable Resistor _______________________________________________________________________________________ 9 MAX5471/MAX5472/MAX5474/MAX5475 C 5V Package Information (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information, go to www.maxim-ic.com/packages.) 6L THIN SOT23.EPS MAX5471/MAX5472/MAX5474/MAX5475 32-Tap, Nonvolatile, Linear-Taper Digital Potentiometers in SOT23 10 ______________________________________________________________________________________ 32-Tap, Nonvolatile, Linear-Taper Digital Potentiometers in SOT23 ______________________________________________________________________________________ 11 MAX5471/MAX5472/MAX5474/MAX5475 Package Information (continued) (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information, go to www.maxim-ic.com/packages.) Package Information (continued) (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information, go to www.maxim-ic.com/packages.) SOT23, 8L.EPS MAX5471/MAX5472/MAX5474/MAX5475 32-Tap, Nonvolatile, Linear-Taper Digital Potentiometers in SOT23 MARKING 0 0 PACKAGE OUTLINE, SOT-23, 8L BODY 21-0078 G 1 1 Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. 12 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2006 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products, Inc.