19-1997; Rev 0; 4/01 Dual, 256-Tap, Up/Down Interface, Digital Potentiometers The MAX5450–MAX5455 are available in 10-pin µMAX and 14-pin TSSOP packages. Each device is guaranteed over the extended–industrial temperature range (-40°C to +85°C). Applications Mechanical Potentiometer Replacement Features ♦ Small-Footprint Packages 10-Pin µMAX (MAX5450/MAX5452/MAX5454) 14-Pin TSSOP (MAX5451/MAX5453/MAX5455) ♦ 256-Tap Positions ♦ Independent Up/Down Potentiometer Controls (MAX5451/MAX5453/MAX5455) ♦ Ultra-Low 0.1µA Supply Current ♦ +2.7V to +5.5V Single-Supply Operation ♦ Low 35ppm/°C End-to-End Temperature Coefficient ♦ Power-On Reset Sets Wiper to Midscale (Position 127) ♦ Glitchless Switching Between the Resistor Taps ♦ 10kΩ, 50kΩ, 100kΩ Resistance Values Ordering Information PART PINPACKAGE TEMP. RANGE R (kΩ) MAX5450EUB -40°C to +85°C 10 µMAX 10 MAX5451EUD -40°C to +85°C 14 TSSOP 10 MAX5452EUB -40°C to +85°C 10 µMAX 50 MAX5453EUD -40°C to +85°C 14 TSSOP 50 MAX5454EUB -40°C to +85°C 10 µMAX 100 MAX5455EUD -40°C to +85°C 14 TSSOP 100 Low-Drift Programmable-Gain Amplifier (PGA) Volume Control Pin Configurations LCD Screen Adjustment Adjustable Voltage References TOP VIEW Adjustable Linear Regulators Programmable Filters, Delays, Time Constants Impedance Matching CS1 1 U/D 2 VDD 3 W1 4 L1 5 CS1 1 14 CS2 9 INC U/D1 2 13 INC1 8 GND U/D2 3 10 CS2 MAX5450 MAX5452 MAX5454 µMAX 7 W2 VDD 4 6 L2 W1 5 12 INC2 MAX5451 MAX5453 MAX5455 11 GND 10 W2 H1 6 9 H2 L1 7 8 L2 TSSOP ________________________________________________________________ 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 MAX5450–MAX5455 General Description The MAX5450–MAX5455 are a family of dual digital potentiometers that perform the same function as a mechanical potentiometer or variable resistor. The MAX5451/MAX5453/MAX5455 have two 3-terminal potentiometers and the MAX5450/MAX5452/MAX5454 have two 2-terminal variable resistors. The MAX5450– MAX5455 operate from a +2.7V to +5.5V single-supply voltage and use an ultra-low supply current of 0.1µA. These devices consist of two fixed resistors each with 256 digitally-controlled wiper contacts. The convenient power-on reset (POR) sets the wiper to midscale position at power-up and the easy-to-use up/down interface allows glitchless switching between resistor taps. Six inputs control the 14-pin MAX5451/ MAX5453/MAX5455 potentiometers. Four inputs control the 10-pin MAX5450/MAX5452/MAX5454 variable resistors. The MAX5450–MAX5455 are ideal for applications requiring digitally-controlled resistors. Three resistance values are available: 10kΩ, 50kΩ, and 100kΩ. An endto-end resistor temperature coefficient of 35ppm/°C and a ratiometric temperature coefficient of 5ppm/°C make the MAX5450–MAX5455 excellent choices for adjustable gain circuit requiring low-temperature drift MAX5450–MAX5455 Dual, 256-Tap, Up/Down Interface, Digital Potentiometers ABSOLUTE MAXIMUM RATINGS VDD to GND ..............................................................-0.3V to +6V CS_, INC_, and U/D_ to GND...................................-0.3V to +6V H_, L_, W_ to GND ......................................-0.3V to (VDD +0.3V) Maximum Continuous Current into H_, L_, and W_............±1mA Continuous Power Dissipation (TA = +70°C) 10-Pin µMAX (derate 6.94mW/°C above +70°C) ..........555mW 14-Pin TSSOP (derate 9.1mW/°C above +70°C) ..........727mW Operating Temperature Range ...........................-40°C to +85°C Junction Temperature ......................................................+150°C Storage Temperature Range .............................-65°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 +5.5V, VH = VDD, VL = 0; TA = TMIN to TMAX, unless otherwise noted. Typical values are at VDD = +5V, TA = +25°C, unless otherwise noted.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS DC PERFORMANCE (Voltage-Divider Mode, MAX5451/MAX5453/MAX5455 Only) Resolution N Integral Nonlinearity (Notes 1 and 2) INL Differential Nonlinearity (Notes 1 and 2) DNL End-to-End Resistor Tempco TCR 8 ±1 VDD = +3V ±1 VDD = +5V ±1 VDD = +3V ±1 Ratiometric Resistor Tempco MAX5451 Full-Scale Error Zero-Scale Error Bits VDD = +5V LSB LSB 35 ppm/°C 5 ppm/°C -8 MAX5453 -1.6 MAX5455 -0.8 MAX5451 +8 MAX5453 +1.6 MAX5455 +0.8 LSB LSB DC PERFORMANCE (Variable Resistor Mode) Resolution Integral Nonlinearity (Notes 1 and 3) N 8 VDD = +5V INL VDD = +3V Differential Nonlinearity (Notes 1 and 3) DNL Bits MAX5450, MAX5451 ±3 MAX5452–MAX5455 ±1 MAX5450, MAX5451 ±4.5 MAX5452–MAX5455 LSB ±2 VDD = +5V ±1 VDD = +3V ±1 LSB DC PERFORMANCE (Resistor Characteristics) Wiper Resistance (Note 4) RW Wiper Capacitance CW VDD = +5V VDD = +3V 2 RHL 550 10 MAX5450, MAX5451 End-To-End Resistance 225 6.5 pF 10 12.5 MAX5452, MAX5453 32 50 62.5 MAX5454, MAX5455 60 100 125 _______________________________________________________________________________________ Ω kΩ Dual, 256-Tap, Up/Down Interface, Digital Potentiometers (VDD = +2.7V to +5.5V, VH = VDD, VL = 0; TA = TMIN to TMAX, unless otherwise noted. Typical values are at VDD = +5V, TA = +25°C, unless otherwise noted.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS DIGITAL INPUTS (Note 5) Input High Voltage VIH Input Low Voltage VIL 0.7 x VDD V 0.3 x VDD Input Leakage Current ±1.0 Input Capacitance 5 V µA pF TIMING CHARACTERISTICS (Analog) Wiper-Settling Time (Note 6) tIW MAX5451 0.5 MAX5453 1.2 MAX5455 1.8 µs TIMING CHARACTERISTICS (Digital, Note 7, Figure 1) Maximum INC Frequency fMAX 7 CS to INC Setup Time tCI 25 MHz ns CS to INC Hold Time tIC 0 ns INC Low Period tIL 25 ns INC High Period tIH 25 ns U/D to INC Setup tDI 50 ns U/D to INC Hold tID 0 ns Supply Voltage VDD 2.7 Supply Current IDD POWER SUPPLIES CS = INC = U/D = VDD or GND 5.5 VDD = +5V 0.7 VDD = +2.7V 0.1 2 V µA Note 1: Linearity is defined in terms of the H_ to L_ code-dependent resistance. Note 2: The DNL and INL are measured with the potentiometer configured as a voltage divider with H_ = VDD and L_ = GND. The wiper terminal is unloaded and measured with an ideal voltmeter. Note 3: The DNL and INL are measured with the potentiometer configured as a variable resistor. For the 3-terminal potentiometers (MAX5451/MAX5453/MAX5455), H_ is unconnected and L_ = GND. For the 2-terminal potentiometers (MAX5450/MAX5452/MAX5454), L_ = GND. At VDD = +5V, the wiper terminal is driven with a source current of 400µA for the 10kΩ configuration, 80µA for the 50kΩ configuration, and 40µA for the 100kΩ configuration. At VDD = +3V, 200µA/40µA/20µA for 10kΩ/50kΩ/100kΩ configuration, respectively. Note 4: The wiper resistance is the worst value measured by injecting the currents given in Note 3 into W_ with L_ = GND. RW_ = (VW_ - VH_) / IW_. Note 5: Device draws higher supply current when digital inputs are driven with voltages between 0.3 x VDD and 0.7 x VDD. (See Supply Current vs. Digital Input Voltage in the Typical Operating Characteristics.) Note 6: 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 Tap-To-Tap Switching Transient in the Typical Operating Characteristics). Note 7: Digital timing is guaranteed by design. _______________________________________________________________________________________ 3 MAX5450–MAX5455 ELECTRICAL CHARACTERISTICS (continued) Typical Operating Characteristics (VDD = +5V, TA = +25°C, unless otherwise noted.) 240 220 VDD = +5V 200 VDD = +3V 320 300 280 VDD = +5V 260 240 220 180 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 320 300 280 260 240 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 WIPER VOLTAGE (V) WIPER VOLTAGE (V) WIPER RESISTANCE vs. WIPER POSITION (10kΩ) WIPER RESISTANCE vs. WIPER POSITION (50kΩ) WIPER RESISTANCE vs. WIPER POSITION (100kΩ) 6 5 4 3 40 35 30 25 20 15 100 90 80 70 60 50 40 30 2 10 20 1 5 10 0 0 32 64 96 128 160 192 224 256 MAX5450/5 toc06 45 W-TO-L RESISTANCE (kΩ) 7 MAX5450/5 toc05 8 50 W-TO-L RESISTANCE (kΩ) MAX5450/5 toc04 9 0 0 32 64 96 128 160 192 224 256 0 32 64 96 128 160 192 224 256 WIPER POSITION WIPER POSITION WIPER POSITION VARIABLE RESISTOR DNL vs. WIPER POSITION (10kΩ) VARIABLE RESISTOR INL vs. WIPER POSITION (MAX5451) VARIABLE RESISTOR DNL vs. WIPER POSITION (50kΩ) 0.30 0.05 0.20 0.10 0.00 -0.20 96 128 160 192 224 256 WIPER POSITION 0.02 0.01 -0.02 -0.30 64 0.03 -0.01 0.00 32 0.04 0.00 -0.10 -0.05 0.05 DNL (LSB) 0.10 MAX5450/5 toc09 0.40 INL (LSB) 0.15 0.06 MAX5450/5 toc08 0.50 MAX5450/5 toc07 0.20 0 VDD = +5V WIPER VOLTAGE (V) 10 0 VDD = +3V 180 160 160 0 360 340 220 200 200 160 4 400 380 MAX5450/5 toc02 340 180 W-TO-L RESISTANCE (kΩ) WIPER RESISTANCE vs. WIPER VOLTAGE (100kΩ) WIPER RESISTANCE (Ω) VDD = +3V 260 360 WIPER RESISTANCE (Ω) 280 WIPER RESISTANCE (Ω) 380 MAX5450/5 toc01 300 WIPER RESISTANCE vs. WIPER VOLTAGE (50kΩ) MAX5450/5 toc03 WIPER RESISTANCE vs. WIPER VOLTAGE (10kΩ) DNL (LSB) MAX5450–MAX5455 Dual, 256-Tap, Up/Down Interface, Digital Potentiometers -0.03 0 32 64 96 128 160 192 224 256 WIPER POSITION 0 32 64 96 128 160 192 224 256 WIPER POSITION _______________________________________________________________________________________ Dual, 256-Tap, Up/Down Interface, Digital Potentiometers VARIABLE RESISTOR INL vs. WIPER POSITION (MAX5453) DNL (LSB) -0.04 -0.06 -0.08 -0.10 -0.12 -0.14 -0.16 0 32 64 96 -0.20 0 32 64 128 160 192 224 256 0 64 0.10 0.02 0.06 256 0.05 0.00 -0.05 -0.10 0.00 160 192 224 0.07 DNL (LSB) INL (LSB) 0.03 128 0.08 0.05 0.04 96 VOLTAGE-DIVIDER DNL vs. WIPER POSITION (50kΩ) MAX5450/5 toc14 0.15 0.01 0.04 0.03 0.02 0.01 0.00 -0.15 -0.01 -0.01 -0.20 -0.02 0 32 64 96 128 160 192 224 0 256 32 64 160 192 224 -0.02 256 0 32 64 0.07 0.06 0.05 0.04 0.03 0.02 0.10 0.00 -0.05 -0.10 0.00 -0.15 256 0.05 0.01 -0.10 160 192 224 0.15 INL (LSB) DNL (LSB) -0.05 128 VOLTAGE-DIVIDER INL vs. WIPER POSITION (100kΩ) 0.05 0.00 96 WIPER POSITION MAX5450/5 toc17 0.08 MAX5450/5 toc16 0.10 128 VOLTAGE-DIVIDER DNL vs. WIPER POSITION (100kΩ) VOLTAGE-DIVIDER INL vs. WIPER POSITION (50kΩ) 0.15 96 WIPER POSITION WIPER POSITION INL (LSB) 32 WIPER POSITION VOLTAGE-DIVIDER INL vs. WIPER POSITION (10kΩ) 0.05 DNL (LSB) 96 WIPER POSITION MAX5450/5 toc13 0.06 -0.05 -0.15 VOLTAGE-DIVIDER DNL vs. WIPER POSITION (10kΩ) 0.07 0.00 -0.10 WIPER POSITION 0.08 MAX5450/5 toc12 0.05 0.05 0.04 0.03 0.02 0.01 0.00 -0.01 -0.02 128 160 192 224 256 0.10 MAX5450/5 toc18 INL (LSB) -0.02 0.15 MAX5450/5 toc15 0.00 0.11 0.10 0.09 0.08 0.07 0.06 INL (LSB) 0.02 VARIABLE RESISTOR INL vs. WIPER POSITION (MAX5455) MAX5450/5 toc11 0.12 MAX5450/5 toc10 0.04 VARIABLE RESISTOR DNL vs. WIPER POSITION (100kΩ) -0.15 -0.01 -0.20 -0.20 -0.02 0 32 64 96 128 160 192 224 WIPER POSITION 256 0 32 64 96 128 160 192 224 WIPER POSITION 256 0 32 64 96 128 160 192 224 256 WIPER POSITION _______________________________________________________________________________________ 5 MAX5450–MAX5455 Typical Operating Characteristics (continued) (VDD = +5V, TA = +25°C, unless otherwise noted.) Typical Operating Characteristics (continued) (VDD = +5V, TA = +25°C, unless otherwise noted.) SUPPLY CURRENT vs. TEMPERATURE SUPPLY CURRENT vs. DIGITAL INPUT VOLTAGE 1.2 VDD = 5V 0.1 IDD (mA) 1.0 0.8 0.6 VDD = 3V 0.01 VDD = +5V 0.8 SUPPLY CURRENT (µA) DIGITAL INPUTS + VDD MAX5450/5 toc20 1 MAX5450/5 toc19 1.4 1.0 0.6 0.4 VDD = +3V 0.4 0.2 0.001 0.2 0 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 0.0001 0 0 1 2 3 4 5 0 6 1 2 3 END-TO-END RESISTANCE % CHANGE vs. TEMPERATURE 5 TEMPERATURE (°C) 10kΩ 0.15 50kΩ 0.10 0.05 MAX5450/5 toc23 MAX5455 W 10mV/div 100kΩ 0 TAP-TO-TAP SWITCHING TRANSIENT MAX5450/5 toc22 0.20 END-TO-END RESISTANCE % CHANGE 4 DIGITAL INPUT VOLTAGE (V) VDD (V) MAX5453 50kΩ -0.05 100kΩ INC_ 5V/div -0.10 MAX5451 -0.15 -0.20 10kΩ -0.25 -40 -20 0 20 40 60 80 1µs/div TEMPERATURE (°C) 6 _______________________________________________________________________________________ MAX5450/5 toc21 SUPPLY CURRENT vs. SUPPLY VOLTAGE IDD (µA) MAX5450–MAX5455 Dual, 256-Tap, Up/Down Interface, Digital Potentiometers Dual, 256-Tap, Up/Down Interface, Digital Potentiometers PIN MAX5451 MAX5453 MAX5455 MAX5450 MAX5452 MAX5454 NAME 1 1 CS1 Chip-Select Input of Resistor 1. Drive low to change wiper position W1 through INC and U/D. — 2 U/D Up/Down Control Input. With U/D low, a high-to-low INC transition decrements wiper position. With U/D high, a high-to-low INC transition increments wiper position. 2 — U/D1 Up/Down Control Input of Resistor 1. With U/D1 low, a high-to-low INC1 transition decrements wiper position W1. With U/D1 high, a high-to-low INC1 transition increments wiper position W1. 3 — U/D2 Up/Down Control Input of Resistor 2. With U/D2 low, a high-to-low INC2 transition decrements wiper position W2. With U/D2 high, a high-to-low INC2 transition increments wiper position W2. 4 3 VDD Power Supply 5 4 W1 Wiper Terminal of Resistor 1 6 — H1 High Terminal of Resistor 1 7 5 L1 Low Terminal of Resistor 1 8 6 L2 Low Terminal of Resistor 2 9 — H2 High Terminal of Resistor 2 Wiper Terminal of Resistor 2 FUNCTION 10 7 W2 11 8 GND Ground — 9 INC Wiper Increment Control Input. With CS1 low, a high-to-low transition increments (U/D high) or decrements (U/D low) wiper position W1. This applies similarly for CS2 and W2. 12 — INC2 Wiper Increment Control Input. With CS2 low, a high-to-low transition increments (U/D2 high) or decrements (U/D2 low) wiper position W2. 13 — INC1 Wiper Increment Control Input. With CS1 low, a high-to-low transition increments (U/D1 high) or decrements (U/D1 low) wiper position W1. 14 10 CS2 Chip-Select Input of Resistor 2. Drive low to change wiper position W2 through INC and U/D. _______________________________________________________________________________________ 7 MAX5450–MAX5455 Pin Description MAX5450–MAX5455 Dual, 256-Tap, Up/Down Interface, Digital Potentiometers CS_ tCI tIC tIL INC_ tIH tDI U/D_ tID tIW W_ Figure 1. Digital Interface and Timing diagram Detailed Description The MAX5450–MAX5455 contain two independent resistor arrays each with 255-resistive elements. 256tap points are accessible to the wiper along the resistor arrays between H and L (Figure 2). Power-on reset circuitry sets the wiper to midscale (position 127) at power-up. Logic inputs CS, U/D, and INC determine the wiper position of the MAX5450–MAX5455. With CS low and U/D high, a high-to-low (falling edge) transition on INC, increments the internal counter, which increases the resistance between W and L. When both CS and U/D are low, a high-to-low INC transition decrements the internal counter, decreasing the resistance between W and L (Figure 1). The wiper performs a make-beforebreak 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 (max/min) of the resistor array, additional transitions in the direction of the endpoint will not change the counter value (the counter will not wrap around). The MAX5450/MAX5452/MAX5454 are similar to the MAX5451/MAX5453/MAX5455 except for internal connections. The MAX5450/MAX5452/MAX5454 internally connect INC1 to INC2, U/D1 to U/D2, W1 to H1, and W2 to H2 (Figures 3 and 4). The internal connections configure the MAX5450/MAX5452/MAX5454 to be variable resistors. 8 Applications Information The MAX5450–MAX5455 are ideal for adjustable voltage or adjustable gain circuits where accurate adjustable resistances are required. Adjustable Current to Voltage Converter Figure 5 shows the MAX5450/MAX5452/MAX5454 with a MAX4250 low-noise op amp to fine-tune a current to voltage converter. The physical sizes of both devices minimize circuit space. Adjustable Gain Amplifier Figures 6a and 6b shows the MAX5450–MAX5455 digitally adjusting the gain of the MAX4493 general-purpose, dual supply op amp. Figure 6a shows the MAX5450/MAX5452/MAX5454 variable resistor in series with a resistor to ground to form the adjustable gain control. Figure 6b shows the MAX5451/MAX5453/ MAX5455 as a 3-terminal potentiometer. In these applications the low 5ppm/°C ratiometric tempco allows for a very stable adjustable gain over temperature. Adjustable Linear Regulator In Figure 7, the MAX5450/MAX5452/MAX5454 is shown digitally adjusting the output voltage of the MAX8866 dual linear regulator. In this circuit, the MAX5450/ MAX5452/MAX5454 is connected in series with a resistor to ground to form the adjustable feedback stage. The 8-bit MAX5450/MAX5452/MAX5454 allows precise tuning of the output voltage. _______________________________________________________________________________________ Dual, 256-Tap, Up/Down Interface, Digital Potentiometers W1 CS1 S256 UP/DOWN COUNTER INC U/D R255 POSITION DECODER L1 VDD S255 R254 GND CS2 S254 MAX5450 MAX5452 MAX5454 POWER-ON RESET UP/DOWN COUNTER W W2 POSITION DECODER L2 R2 S3 Figure 3. MAX5450/MAX5452/MAX5454 Simplified Functional Diagram R1 S2 S1 L Figure 2. Simplified Digital Potentiometer Resistor Array W R3 H1 VDD CS1 INC1 U/D1 POSITION DECODER W1 L1 VDD GND MAX5450 MAX5452 MAX5454 R2 UP/DOWN COUNTER POWER-ON RESET MAX5451 MAX5453 MAX5455 H2 IS R1 VOUT L MAX4250 VOUT R = R3 1 + 2 + R2 R1 IS ( ) CS2 INC2 U/D2 UP/DOWN COUNTER POSITION DECODER W2 Figure 5. Adjustable Current to Voltage Converter L2 Figure 4. MAX5451/MAX5453/MAX5455 Simplified Functional Diagram _______________________________________________________________________________________ 9 MAX5450–MAX5455 H MAX5450–MAX5455 Dual, 256-Tap, Up/Down Interface, Digital Potentiometers VCC VIN VOUT OUT1 VOUT1 OUT2 VOUT2 W1 MAX4493 W2 MAX8866 VEE MAX5450 MAX5452 MAX5454 W V+ MAX5450 MAX5452 MAX5454 IN L1 SHDN1 SET1 SHDN2 SET2 L2 GND L Figure 7. Adjustable Dual Linear Regulator Figure 6a. Variable Resistor Adjustable-Gain Amplifier Truth Table VCC VIN VOUT MAX4493 VEE W CS U/D INC H X X O L L ↑ O L H ↑ O L L ↓ − L H ↓ + X = Don’t care O = Previous State ↓ = High-to-Low Transition – = Decrement ↑ = Low-to-High Transition + = Increment W H L Chip Information MAX5451 MAX5453 MAX5455 TRANSISTOR COUNT: 9680 PROCESS: CMOS Figure 6b. Potentiometer Adjustable-Gain Amplifier 10 ______________________________________________________________________________________ Dual, 256-Tap, Up/Down Interface, Digital Potentiometers 10LUMAX.EPS ______________________________________________________________________________________ 11 MAX5450–MAX5455 Package Information Dual, 256-Tap, Up/Down Interface, Digital Potentiometers TSSOP,NO PADS.EPS MAX5450–MAX5455 Package Information (continued) 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 © 2001 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.