19-1956; Rev 2; 9/02 32-Tap FleaPoT ™, 2-Wire Digital Potentiometers Features ♦ Miniature SC70 and SOT23 Packages ♦ 0.3µA Ultra-Low Supply Current ♦ +2.7V to +5.5V Single-Supply Operation ♦ Glitchless Switching Between Resistor Taps ♦ Power-On Reset to Midscale ♦ 2-Wire Up/Down Serial Interface ♦ 10kΩ, 50kΩ, and 100kΩ Resistance Values Ordering Information Applications LCD Screen Adjustment PART Volume Control Mechanical Potentiometer Replacement Gain Adjustment Line Impedance Matching FleaPoT is a trademark of Maxim Integrated Products Inc. Functional Diagram appears at end of data sheet. TEMP RANGE TOP PINR (kΩ) PACKAGE MARK MAX5460EXK -40°C to +85°C 5 SC70 ACA MAX5461EXT -40°C to +85°C 6 SC70 AAP 100 100 MAX5462EXT -40°C to +85°C 6 SC70 AAQ 100 MAX5463EXK -40°C to +85°C 5 SC70 ACB 50 MAX5464EXT -40°C to +85°C 6 SC70 AAR 50 MAX5465EXT -40°C to +85°C 6 SC70 AAS 50 MAX5466EUK -40°C to +85°C 5 SOT23 ADQQ 10 MAX5467EUT -40°C to +85°C 6 SOT23 AARH 10 MAX5468EUT -40°C to +85°C 6 SOT23 AARI 10 Pin Configurations TOP VIEW VDD 1 5 H GND 2 U/D 3 MAX5460 MAX5463 MAX5466 SOT23, SC70 4 CS VDD 1 6 H VDD 1 6 H GND 2 5 L GND 2 5 W 4 CS U/D 3 4 CS U/D 3 MAX5461 MAX5464 MAX5467 SOT23, SC70 MAX5462 MAX5465 MAX5468 SOT23, SC70 ________________________________________________________________ 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 MAX5460–MAX5468 General Description The MAX5460–MAX5468 linear-taper digital potentiometers perform the same function as a mechanical potentiometer or a variable resistor. These devices consist of a fixed resistor and a wiper contact with 32-tap points that are digitally controlled through a 2-wire serial interface. The MAX5462/MAX5465/MAX5468 are configured as potentiometers. The rest of the devices in this family are configured as variable resistors. See Pin Configurations for part functionality. Three resistance values are available: 10kΩ (MAX5466/ MAX5467/MAX5468), 50kΩ (MAX5463/MAX5464/ MAX5465), and 100kΩ (MAX5460/MAX5461/MAX5462). The MAX5460–MAX5465 (100kΩ and 50kΩ) are available in space-saving 5-pin and 6-pin SC70 packages. The MAX5466/MAX5467/MAX5468 (10kΩ) are available in 5-pin and 6-pin SOT23 packages. MAX5460–MAX5468 32-Tap FleaPoT ™, 2-Wire Digital Potentiometers ABSOLUTE MAXIMUM RATINGS VDD to GND ..............................................................-0.3V to +6V All Other Pins to GND.................................-0.3V to (VDD + 0.3)V Input and Output Latch-Up Immunity.............................±200mA Maximum Continuous Current into H, L, and W MAX5460/MAX5461/MAX5462 (100kΩ) .......................±0.6mA MAX5463/MAX5464/MAX5465 (50kΩ) .........................±1.3mA MAX5466/MAX5467/MAX5468 (10kΩ) .........................±1.3mA Continuous Power Dissipation (TA = +70°C) 5-pin SC70 (derate 3.1mW/°C above TA = +70°C)..........247mW 5-pin SOT23 (derate 7.1mW/°C above TA = +70°C)........571mW 6-pin SC70 (derate 3.1mW/°C above TA = +70°C) ..........245mW 6-pin SOT23 (derate 8.7mW/°C above TA = +70°C).....695.7mW Operating Temperature Range ...........................-40°C to +85°C Junction Temperature ......................................................+150°C Storage Temperature Range .............................-65°C to +150°C Soldering 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 (V DD = +2.7V to +5.5V, V H = V DD, V L = 0, T A = -40°C to +85°C. Typical values are at V DD = +2.7V, T A = +25°C, unless otherwise noted.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS DC PERFORMANCE Resolution 32 End-to-End Resistance End-to-End Resistance Tempco Taps MAX5460/MAX5461/MAX5462 75 100 125 MAX5463/MAX5464/MAX5465 37.5 50 62.5 MAX5466/MAX5467/MAX5468 7.5 10 12.5 TCR 35 Ratiometric Resistance Tempco INL Differential Nonlinearity DNL ±0.5 ppm/°C ±1 ±1 ±0.1 Full-Scale Error Zero-Scale Error Wiper Resistance ppm/°C 5 Integral Nonlinearity LSB LSB LSB 1 RW kΩ MAX5460–MAX5465 600 1200 MAX5466/MAX5467/MAX5468 160 240 LSB Ω DIGITAL INPUTS Input High Voltage VIH Input Low Voltage VIL 0.7 x VDD V 0.3 x VDD V TIMING CHARACTERISTICS (Figures 1, 2) 2 U/D Mode to CS Setup tCU 25 ns CS to U/D Step Setup tCI 50 ns CS to U/D Step Hold tIC 25 ns U/D Step Low Period tIL 25 ns U/D Step High Period tIH 25 Up/Down Toggle Rate (Note 1) fTOGGLE Output Settling Time (Note 2) tSETTLE ns 1 100kΩ variable resistor configuration, CL = 10pF 100kΩ potentiometer configuration, CL = 10pF 1 0.25 _______________________________________________________________________________________ MHz µs 32-Tap FleaPoT ™, 2-Wire Digital Potentiometers (V DD = +2.7V to +5.5V, V H = V DD, V L = 0, T A = -40°C to +85°C. Typical values are at V DD = +2.7V, T A = +25°C, unless otherwise noted.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS POWER SUPPLIES Supply Voltage VDD Active Supply Current (Note 3) IDD Standby Supply Current (Note 4) ISD 2.7 VDD = +5V 5.5 V 25 µA 1 µA 0.3 Note 1: Up/Down Toggle Rate: fTOGGLE = 1 t SETTLE Note 2: Typical settling times are dependent on end-to-end resistance. Note 3: Supply current taken while changing wiper tap, fTOGGLE = 1MHz. Note 4: Supply current taken while wiper position is fixed. Typical Operating Characteristics (TA = +25°C, unless otherwise noted.) WIPER RESISTANCE vs. WIPER VOLTAGE (MAX5466/MAX5467/MAX5468) 500 VDD = +5V 300 200 140 120 100 VDD = +5V 80 60 40 100 20 0 0 -0.05 50kΩ, 100kΩ -0.10 -0.15 -0.20 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 -40 -15 10 35 60 WIPER VOLTAGE (V) WIPER VOLTAGE (V) TEMPERATURE (°C) W-TO-L RESISTANCE vs. TAP POSITION SUPPLY CURRENT vs. TEMPERATURE TAP-TO-TAP SWITCHING TRANSIENT (MAX5460) 0.50 MAX5460 toc04 120 100 0.45 0.40 100kΩ 80 60 50kΩ 40 0.35 CURRENT (µA) RESISTANCE (kΩ) 10kΩ 0 -0.25 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 MAX5460 toc05 0 0.05 MAX5460 toc03 VDD = +2.7V 160 0.10 VDD = +5V 85 MAX5460 toc06 400 MAX5460 toc02 VDD = +2.7V 180 WIPER RESISTANCE (Ω) WIPER RESISTANCE (Ω) 600 200 MAX5460 toc01 700 END-TO-END RESISTANCE % CHANGE vs. TEMPERATURE END-TO-END RESISTANCE % CHNAGE WIPER RESISTANCE vs. WIPER VOLTAGE (MAX5460–MAX5465) U/D 2V/div 0.30 0.25 0.20 0.15 VDD = +2.7V 0.10 20 10kΩ 0 OUTPUT W 100mV/div 0.05 0.00 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 TAP POSITION -40 -15 10 35 60 85 200ns/div TEMPERATURE (°C) _______________________________________________________________________________________ 3 MAX5460–MAX5468 ELECTRICAL CHARACTERISTICS (continued) Typical Operating Characteristics (continued) (TA = +25°C, unless otherwise noted.) R-DNL ERROR vs. INPUT CODE (100kΩ) 0.06 0.02 0 R-INL (LSB) 0 -0.02 -0.04 R-DNL (LSB) 0.04 0.02 0.02 0 -0.02 -0.02 -0.04 -0.06 -0.08 -0.04 -0.06 -0.06 -0.10 -0.08 -0.08 -0.12 -0.10 -0.10 0 5 10 15 20 25 -0.14 0 30 5 10 15 20 25 0 30 0.10 -0.05 -0.05 0.20 5 10 15 20 25 0.10 0.05 0 -0.15 -0.05 -0.20 -0.10 -0.25 -0.10 -0.15 0 30 INPUT CODE (DECIMAL) 30 0.15 0 -0.10 0 25 0.25 R-INL (LSB) R-DNL LSB 0.05 20 R-INL ERROR vs. INPUT CODE (10kΩ) 0.05 0.10 15 0.30 MAX5460 toc11 0.15 MAX5460 toc10 0.15 10 INPUT CODE (DECIMAL) R-DNL ERROR vs. INPUT CODE (10kΩ) R-INL ERROR vs. INPUT CODE (50kΩ) 0.20 0 5 INPUT CODE (DECIMAL) INPUT CODE (DECIMAL) MAX5460 toc12 R-DNL (LSB) 0.08 MAX5460 toc09 0.04 0.04 MAX5460 toc08 0.06 R-DNL ERROR vs. INPUT CODE (50kΩ) R-INL ERROR vs. INPUT CODE (100kΩ) 0.10 MAX5460 toc07 0.08 R-INL LSB MAX5460–MAX5468 32-Tap FleaPoT ™, 2-Wire Digital Potentiometers 5 10 15 25 20 INPUT CODE (DECIMAL) 30 0 5 10 15 20 25 30 INPUT CODE (DECIMAL) Pin Description PIN 4 MAX5460 MAX5463 MAX5466 MAX5461 MAX5464 MAX5467 MAX5462 MAX5465 MAX5468 1 1 1 VDD Power Supply 2 2 2 GND Ground 3 3 3 U/D Up/Down Control Input. With CS low, a low-to-high transition increments or decrements the wiper position. 4 4 4 CS Chip Select Input. A high-to-low CS transition determines the mode: increment if U/D is high, or decrement if U/D is low. NAME FUNCTION 5 6 6 H High Terminal of Resistor — 5 — L Low Terminal of Resistor — — 5 W Wiper Terminal of Resistor _______________________________________________________________________________________ 32-Tap FleaPoT ™, 2-Wire Digital Potentiometers The MAX5460–MAX5468 consist of a fixed resistor and a wiper contact with 32-tap points that are digitally controlled through a 2-wire serial interface. Three resistance values are available: 10kΩ (MAX5466/MAX5467/ MAX5468), 50kΩ (MAX5463/MAX5464/MAX5465), and 100kΩ (MAX5460/MAX5461/MAX5462). The MAX5462/MAX5465/MAX5468 are designed to operate as potentiometers. In this configuration, the low terminal of the resistor array is connected to ground (pin 2). The MAX5461/MAX5464/MAX5467 perform as variable resistors. In these devices, the wiper terminal and high terminal of the resistor array are connected at pin 5. The MAX5460/MAX5463/MAX5466 are similar variable resistors, except the low terminal is connected to ground (pin 2). Digital Interface Operation The MAX5460–MAX5468 have two modes of operation when the serial interface is active: increment and decrement mode. The serial interface is only active when CS is low. The CS and U/D inputs control the position of the wiper along the resistor array. When CS transitions from high to low, the part will go into increment mode if U/D is high, and into decrement mode if U/D is low. Once the mode is set, the device will remain in that mode until CS goes high again. A low-to-high transition at the U/D pin will increment or decrement the wiper position depending on the current mode (Figures 1 and 2). When the CS input transitions to high (serial interface inactive), the value of the counter is stored and the wiper position is maintained. Note that when the wiper reaches the maximum (or minimum) tap position, the wiper will not wrap around to the minimum (or maximum) position. CS tCU tIC tIL U/D tIH tCI tSETTLE tSETTLE W NOTE: "W" IS NOT A DIGITAL SIGNAL. IT REPRESENTS WIPER TRANSITIONS. Figure 1. Serial Interface Timing Diagram, Increment Mode CS tIC tCU tIH U/D tIL tCI W tSETTLE tSETTLE NOTE: "W" IS NOT A DIGITAL SIGNAL. IT REPRESENTS WIPER TRANSITIONS. Figure 2. Serial Interface Timing Diagram, Decrement Mode _______________________________________________________________________________________ 5 MAX5460–MAX5468 Detailed Description MAX5460–MAX5468 32-Tap FleaPoT ™, 2-Wire Digital Potentiometers Power-On Reset All parts in this family feature power-on reset (POR) circuitry that sets the wiper position to midscale at powerup. By default, the chip is in the increment mode. Applications Information The MAX5460–MAX5468 are intended for circuits requiring digitally controlled adjustable resistance, such as LCD contrast control, where voltage biasing adjusts the display contrast. Controlling a Switch-Mode LCD Bias Generator Figure 3 shows an application where the variable resistor is used with a MAX1771 to make an adjustable positive LCD-bias circuit. The output of the MAX1771 is a positive voltage that is digitally controlled through the MAX5461/MAX5464/MAX5467. Similarly, Figure 4 shows the application of the variable resistor in a digitally controlled negative LCD-bias circuit along with the MAX774/MAX775/MAX776. VIN = 5V Alternatively, use an op amp to provide buffering and gain to the output of the MAX5462/MAX5465/MAX5468. Connect the mechanical potentiometer to the positive input of a noninverting op amp (Figure 5) to select a portion of the input signal by digitally controlling the wiper terminal. Figure 6 shows a similar circuit for the MAX5461/MAX5464/MAX5467. Adjustable Gain Figure 7 shows how to use the variable resistor to digitally adjust the gain of a noninverting op amp configuration. Connect the MAX5461/MAX5464/MAX5467 in series with a resistor to ground to form the adjustable gain control of a noninverting amplifier. The MAX5460– MAX5468 have a low 5ppm/°C ratiometric tempco that allows for a very stable adjustable gain configuration over temperature. VIN C1 68µF C2 0.1µF C1 150µF 2 L1 22µH V+ 5 REF C3 0.1µF Alternative Positive LCD Bias Control 4 SHDN MAX1771 EXT 6 AGND CS FB 1 VOUT = 12V AT 0.5A D1 1N5817-22 R2 3 V+ MAX5461 MAX5464 MAX5467 5 R3 0.07Ω SHDN CS 6 FB N MTD20N03HDL RSENSE 40mΩ 1 OUT 2 C4 300µF 8 3 C2 0.1µF EXT 7 Q1 Si9435 P VOUT MAX774 MAX775 MAX776 R2 RVAR GND 7 C5 MAX5461 MAX5464 MAX5467 RVAR R1 C3 0.1µF R1 L1 22µH REF GND 8 C4* * MAX774 = 330µF, 10V VREF = 1.5V MAX775/MAX776 = 120µF, 20V VOUT(MAX) R2 = +1 R1 VREF ( VOUT(MIN) R2 = R1 + RVAR(MAX) VREF Figure 3. Adjustable Positive LCD Bias 6 4 1N5822/ MBR340 VOUT(MAX) R2 VOUT(MIN) R2 = , = R1 VREF R1 + RVAR VREF ) +1 VREF - VFB ≥ 5µA (FOR 2% GAIN-SETTING ACCURACY) R1 + RVAR Figure 4. Adjustable Negative LCD Bias _______________________________________________________________________________________ 32-Tap FleaPoT ™, 2-Wire Digital Potentiometers MAX5460–MAX5468 +5V +5V H H 30V 30V W VOUT VOUT L L MAX5461 MAX5464 MAX5467 MAX5462 MAX5465 MAX5468 Figure 6. Positive LCD Bias Control Figure 5. Positive LCD Bias Control VCC VCC VIN VIN VOUT VOUT H W H L L MAX5461 MAX5464 MAX5467 MAX5462 MAX5465 MAX5468 a) b) Figure 7. Adjustable Gain Circuit _______________________________________________________________________________________ 7 32-Tap FleaPoT ™, 2-Wire Digital Potentiometers MAX5460–MAX5468 Functional Diagram H VDD GND CS MAX5460–MAX5468 UP/DN COUNTER 32-POSITION DECODER W U/D L Chip Information TRANSISTOR COUNT: 792 8 _______________________________________________________________________________________ 32-Tap FleaPoT ™, 2-Wire Digital Potentiometers SC70, 5L.EPS SOT5L.EPS _______________________________________________________________________________________ 9 MAX5460–MAX5468 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.) Package Information (continued) 6LSOT.EPS (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.) SC70, 6L.EPS MAX5460–MAX5468 32-Tap FleaPoT ™, 2-Wire Digital Potentiometers 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. 10 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2002 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.