19-2657; Rev 0; 10/02 ±15V, 128-Tap, Low-Drift Digital Potentiometers Features ♦ +10V to +30V Single-Supply Operation ♦ -28V to -10V Single Negative Supply Operation ♦ ±5V to ±15V Dual-Supply Operation ♦ 128 Tap Positions ♦ Uncommitted High-Voltage Amplifier (MAX5437/MAX5439) ♦ Low Temperature Coefficient 35ppm/°C (End-to-End) 5ppm/°C (Ratiometric) ♦ Small-Footprint Packages 10-Pin µMAX (MAX5436/MAX5438) 14-Pin TSSOP (MAX5437/MAX5439) ♦ Glitchless Switching Between the Resistor Taps ♦ 3-Wire SPI/QSPI/MICROWIRE-Compatible Serial Interface ♦ 50kΩ/100kΩ End-to-End Resistances ♦ Power-On Reset: Wiper Goes to Midscale (Position 64) Ordering Information PART Applications LCD Screen Contrast Adjustment TEMP RANGE PINPACKAGE RESISTANCE (kΩ) MAX5436EUB -40°C to +85°C 10 µMAX 50 MAX5437EUD -40°C to +85°C 14 TSSOP 50 MAX5438EUB -40°C to +85°C 10 µMAX 100 MAX5439EUD -40°C to +85°C 14 TSSOP 100 Data-Acquisition Systems Mechanical Potentiometer Replacement Pin Configurations Low-Drift Programmable Gain Amplifier Audio Volume Control TOP VIEW SCLK 1 10 VCC DIN 2 CS 3 MAX5436/ MAX5438 GND 4 VSS 5 SPI/QSPI are trademarks of Motorola, Inc. 9 L DIN 2 13 L 8 W CS 3 12 W 7 H SHDN 4 6 VDD µMAX 14 VCC SCLK 1 GND 5 MAX5437/ MAX5439 11 H 10 VDD VSS 6 9 IN+ OUT 7 8 IN- TSSOP MICROWIRE is a trademark of National Semiconductor Corp. ________________________________________________________________ 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 MAX5436–MAX5439 General Description The MAX5436–MAX5439 are 128-tap high-voltage (±5V to ±15V) digital potentiometers in packages that are half the size of comparable devices in 8-pin SO. They perform the same function as mechanical potentiometers, but replace the mechanics with a simple digital interface. The digital logic is powered by a separate single +2.7V to +5.25V supply voltage (VCC). The resistor string uses its own analog supplies (V DD and V SS ) that require VDD - VSS to be greater than 9V and less than 31.5V. This allows for greater flexibility in voltage ranges that can be used with these devices. Examples of analog supply ranges include not only dual voltages of ±5V to ±15V, but single-supply voltages, such as +10V, +15V, +30V, -30V, and more, as long as the ranges of VDD - VSS and VCC VSS are met. The MAX5437/MAX5439 include an on-chip, highvoltage, uncommitted amplifier, providing additional reductions in board space and cost. Other features include low 35ppm/°C end-to-end and 5ppm/°C ratiometric resistor temperature coefficients, a 3-wire SPI™/ QSPI™/MICROWIRE™-compatible serial interface, and a power-on reset to midscale. The MAX5436/MAX5438 are available in 10-pin µMAX packages. The MAX5437/MAX5439 are available in 14pin TSSOP package. Each device is guaranteed over the extended temperature range of -40°C to +85°C. MAX5436–MAX5439 ±15V, 128-Tap, Low-Drift Digital Potentiometers ABSOLUTE MAXIMUM RATINGS VDD to GND, VSS = GND........................................-0.3V to +34V VSS to GND, VDD = GND........................................-34V to +0.3V VDD to VSS ..............................................................-0.3V to +34V VDD to VCC ........................................................-6.3V to +28.75V VCC to VSS ..............................................................-0.3V to +34V VCC to GND ..............................................................-0.3V to +6V DIN, SCLK, CS, SHDN ...............................-0.3V to (VCC + 0.3V) H, L, W, IN+, IN-, OUT .....................(VSS - 0.3V) to (VDD + 0.3V) Maximum Continuous Current into H, L, and W MAX5436–MAX5439.......................................................±1mA Continuous Power Dissipation (TA = +70°C) 10-Pin µMAX (derate 6.94mW/°C above +70°C) .........556mW 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 = +15V, VSS = -15V, VCC = +5V, VH = VDD, VL = VSS, TA = -40°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C, unless otherwise noted.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS DC PERFORMANCE (Voltage-Divider Mode) Resolution 2N Integral Nonlinearity INL (Note 1) ±1 LSB Differential Nonlinearity DNL (Note 1) ±1 LSB End-to-End Resistor Tempco TCR 128 Ratiometric Resistor Tempco Full-Scale Error RHL = 50kΩ (MAX5436/MAX5438) Taps 35 ppm/°C 5 ppm/°C -0.3 LSB LSB Zero-Scale Error RHL = 50kΩ (MAX5436/MAX5438) +0.3 Full-Scale Error RHL = 100kΩ (MAX5437/MAX5439) -0.15 LSB Zero-Scale Error RHL = 100kΩ (MAX5437/MAX5439) +0.15 LSB DC PERFORMANCE (Variable-Resistor Mode) Resolution 2N Integral Nonlinearity INL (Note 2) ±1 LSB Differential Nonlinearity DNL (Note 2) ±1 LSB 2 kΩ 128 Taps DC PERFORMANCE (Resistor Characteristics) Wiper Resistance WR (Note 3) Wiper Capacitance WC Midscale 0.9 6 pF MAX5437/MAX5439 75 100 125 MAX5436/MAX5438 37.5 50 62.5 Input High Voltage VCC = 4.75V to 5.25V (Note 4) 2.4 Input Low Voltage VCC = 4.75V to 5.25V End-to-End Resistance RHL kΩ DIGITAL INPUTS 2 _______________________________________________________________________________________ V 0.8 V ±15V, 128-Tap, Low-Drift Digital Potentiometers (VDD = +15V, VSS = -15V, VCC = +5V, VH = VDD, VL = VSS, TA = -40°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C, unless otherwise noted.) PARAMETER SYMBOL CONDITIONS Input High Voltage VCC = 2.7V to 3.6V Input Low Voltage VCC = 2.7V to 3.6V MIN TYP MAX 2.0 V Input Leakage Current Input Capacitance UNITS 0.6 V ±1.0 µA 5.0 pF DYNAMIC CHARACTERISTICS (Analog) Wiper -3dB Bandwidth Wiper Settling Time BWW tIL RHL = 50kΩ, midscale, VH = 1.5VP-P, CWIPER = 20pF, voltage-divider mode 400 RHL = 100kΩ, midscale, VH = 1.5VP-P, CWIPER = 20pF, voltage-divider mode 200 kHz CWIPER = 20pF, code 1 to code 127, settle to 0.5LSB 5 µs IB 15 nA VOS ±6 mV VOSD 10 µV/°C AMPLIFIER CHARACTERISTICS (Analog) Input Bias Current Input Offset Voltage Offset-Voltage Temperature Drift Input Offset Current IOS Unity-Gain Bandwidth Slew Rate UBWA CLOAD = 250pF SR Large-Signal Voltage Gain Input Noise AVO VN 2 nA 100 kHz 0.25 V/µs RLOAD = 100kΩ, VOUT = ±14V 100 V/mV f = 1kHz 110 nV/√Hz Input Compliance CMRI Output Compliance CMRO DC CMRR CMRR 68 dB DC PSRR PSRR 70 dB ILOAD = ±5mA VSS + 1 VDD - 2 VSS + 1 VDD - 1 V V TIMING CHARACTERISTICS (Digital) (Note 5, Figure 3) SCLK Clock Frequency fCLK 0 SCLK Clock Period tCP 100 ns SCLK Pulse Width High tCH 40 ns SCLK Pulse Width Low tCL 40 ns CS Fall to SCLK Rise Setup Time tCSS 40 ns SCLK Rise to CS Rise Hold Time tCSH 10 ns tDS 40 ns DIN Setup Time 10 MHz DIN Hold Time tDH 0 ns SCLK Rise to CS Fall Delay tCSO 10 ns CS Rise to SCLK Rise Hold tCS1 40 ns CS Pulse Width High tCSW 100 ns POWER SUPPLIES Positive Analog Supply Voltage VDD 0 31.5 V Negative Analog Supply Voltage VSS -28.8 0 V _______________________________________________________________________________________ 3 MAX5436–MAX5439 ELECTRICAL CHARACTERISTICS (continued) MAX5436–MAX5439 ±15V, 128-Tap, Low-Drift Digital Potentiometers ELECTRICAL CHARACTERISTICS (continued) (VDD = +15V, VSS = -15V, VCC = +5V, VH = VDD, VL = VSS, TA = -40°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C, unless otherwise noted.) PARAMETER SYMBOL CONDITIONS MAX UNITS 9.0 TYP 31.5 V 2.70 5.25 V 2.7 31.5 V VDS Digital Supply Voltage VCC Digital Supply to Negative Analog Supply Separation VCS Power-On Reset Threshold POR Digital Supply Current ICC (Note 4) 30 50 IDD MAX5436/MAX5438 SHDN = GND for MAX5437/MAX5439 30 60 SHDN = VCC 105 215 MAX5436/MAX5438 SHDN = GND for MAX5437/MAX5439 55 110 SHDN = VCC 130 250 Positive Analog Supply Current Negative Analog Supply Current ISS VDD - VSS MIN Analog Supply Separation VCC - VSS 1.6 V µA µA µA Note 1: The DNL and INL are measured with the potentiometer configured as a voltage-divider with H = VDD and L = VSS. The wiper terminal is unloaded. Note 2: The DNL and INL are measured with the potentiometer configured as a variable resistor. H is unconnected and L = VSS. The wiper terminal is driven with a source current of 80µA for the 50kΩ configuration and 40µA for the 100kΩ configuration. Note 3: The wiper resistance is measured assuming the source currents given in Note 2. Note 4: Device draws current in excess of the specified supply current when a digital input is driven with a voltage of VIN < VCC 0.6V or VIN > 0.5V. This is due to the CMOS input stage crowbar current. At VIN = 2.4V with VCC = 5.25V, this supply current can be as high as 1.6mA. Note 5: Guaranteed by design and characterization. 4 _______________________________________________________________________________________ ±15V, 128-Tap, Low-Drift Digital Potentiometers 1025 1000 975 950 2200 2000 1800 925 1600 900 1400 875 1200 850 16 32 48 64 80 96 112 128 0.10 0.05 0 50kΩ -0.05 -0.10 100kΩ -0.15 -0.20 -0.25 1000 0 16 32 48 64 80 96 -15 -40 112 128 10 35 85 INPUT CODE TEMPERATURE (°C) W-TO-L RESISTANCE CHANGE vs. INPUT CODE DIGITAL SUPPLY CURRENT vs. TEMPERATURE MIDSCALE SWITCHING TRANSIENT (CODE 63 TO CODE 64) 90 80 100kΩ 70 60 50 50kΩ 40 30 20 MAX5436 toc06 40 MAX5436 toc05 MAX5436 toc04 100 35 CS 2V/div 30 25 20 VW-L 100mV/div 15 10 CWIPER = 20pF 10 32 48 64 80 96 -40 -15 10 35 60 TEMPERATURE (°C) VARIABLE-RESISTOR DNL vs. INPUT CODE (50kΩ) VARIABLE-RESISTOR DNL vs. INPUT CODE (100kΩ) 0.10 MAX5436 toc07 0.10 CONDITIONS OF NOTE 2 0.08 112 128 INPUT CODE 0.06 0.06 0.04 0.02 0.02 DNL (LSB) 0.04 0 -0.02 VARIABLE-RESISTOR INL vs. INPUT CODE (50kΩ) 0 -0.04 -0.06 -0.06 -0.08 -0.08 16 32 48 64 80 INPUT CODE 96 112 128 CONDITIONS OF NOTE 2 0.25 0.15 0.10 0.05 0 -0.05 -0.10 0 0.30 0.20 -0.02 -0.04 -0.10 CONDITIONS OF NOTE 2 0.08 100ns/div 85 INL (LSB) 16 MAX5436 toc08 0 MAX5436 toc09 0 DNL (LSB) 60 INPUT CODE DIGITAL SUPPLY CURRENT (µA) 0 RESISTANCE (kΩ) 2400 0.15 MAX5436 toc03 2600 RESISTANCE (Ω) RESISTANCE (Ω) 1050 VDD = +5V VSS = -5V CONDITIONS OF NOTE 2 2800 END-TO-END RESISTANCE % CHANGE CONDITIONS OF NOTE 2 1075 3000 MAX5436 toc01 1100 END-TO-END RESISTANCE % CHANGE vs. TEMPERATURE WIPER RESISTANCE vs. INPUT CODE MAX5436 toc02 WIPER RESISTANCE vs. INPUT CODE -0.10 0 16 32 48 64 80 INPUT CODE 96 112 128 0 16 32 48 64 80 96 112 128 INPUT CODE _______________________________________________________________________________________ 5 MAX5436–MAX5439 Typical Operating Characteristics (VDD = +15V, VSS = -15V, VCC = +5V, VH = VDD, VL = VSS, TA = +25°C, unless otherwise noted.) Typical Operating Characteristics (continued) (VDD = +15V, VSS = -15V, VCC = +5V, VH = VDD, VL = VSS, TA = +25°C, unless otherwise noted.) VARIABLE-RESISTOR INL vs. INPUT CODE (100kΩ) 0.006 0.10 DNL (LSB) 0.05 0 -0.05 0.008 0.006 0.004 0.004 0.002 0.002 0 -0.002 0 -0.002 -0.004 -0.004 -0.006 -0.006 -0.10 -0.008 -0.008 -0.15 -0.010 -0.010 32 48 64 80 96 112 128 0 16 32 48 64 80 96 64 80 96 112 128 VOLTAGE-DIVIDER INL vs. INPUT CODE (50kΩ) VOLTAGE-DIVIDER INL vs. INPUT CODE (100kΩ) WIPER FREQUENCY RESPONSE AT MIDSCALE (100kΩ) 0.04 0.03 0.02 0.01 0.01 INL (LSB) 0.02 0 -0.01 0 -2 -6 0 -0.01 -8 -10 -12 -0.02 -14 -0.03 -0.03 -16 -0.04 -0.04 -18 -0.05 -0.05 -20 48 64 80 96 112 128 VH = 1.5VP-P CWIPER = 20pF -4 -0.02 32 MAX5436 toc15 0.05 MAX5436 toc13 0.03 0 16 32 48 64 80 112 128 96 0.01 0.1 1 10 100 1000 INPUT CODE INPUT CODE FREQUENCY (kHz) AMPLIFIER SMALL-SIGNAL FREQUENCY RESPONSE AMPLIFIER OUTPUT vs. OUTPUT LOAD CURRENT AMPLIFIER INPUT-REFERRED OFFSET vs. TEMPERATURE 13.999 AMPLIFIER OUTPUT (V) 0 -5 -10 VIN = +13V GAIN SETTING 1.077 0 -0.2 -0.4 -0.6 OFFSET (mV) VIN = 50mVP-P UNITY GAIN MAX5436 toc18 14.000 MAX5436 toc16 5 48 INPUT CODE 0.04 16 32 INPUT CODE 0.05 0 16 0 112 128 INPUT CODE GAIN (dB) 16 MAX5436 toc14 0 MAX5436 toc17 INL (LSB) 0.15 MAX5436 toc12 0.008 DNL (LSB) 0.20 0.010 MAX5436 toc11 0.010 MAX5436 toc10 CONDITIONS OF NOTE 2 INL (LSB) VOLTAGE-DIVIDER DNL vs. INPUT CODE (100kΩ) VOLTAGE-DIVIDER DNL vs. INPUT CODE (50kΩ) 0.25 GAIN (dB) MAX5436–MAX5439 ±15V, 128-Tap, Low-Drift Digital Potentiometers 13.998 13.997 -0.8 -1.0 -1.2 -1.4 -15 13.996 -1.6 -20 13.995 -2.0 -1.8 0.01 0.1 1 10 FREQUENCY (kHz) 6 100 1000 0 2 4 6 LOAD CURRENT (mA) 8 10 -40 -15 10 35 TEMPERATURE (°C) _______________________________________________________________________________________ 60 85 ±15V, 128-Tap, Low-Drift Digital Potentiometers PIN MAX5436/ MAX5438 1 MAX5437/ MAX5439 1 NAME DESCRIPTION SCLK Serial Clock Input 2 2 DIN Serial Data Input 3 3 CS Chip Select — 4 SHDN 4 5 GND Analog and Digital Ground 5 6 VSS Negative Analog Supply. Bypass with a 0.1µF capacitor to GND. — 7 OUT Amplifier Output — 8 IN- — 9 IN+ Amplifier Positive Input 6 10 VDD Positive Analog Supply. Bypass with a 0.1µF capacitor to GND. 7 11 H High Terminal of Resistor 8 12 W Wiper Terminal of Resistor 9 13 L Low Terminal of Resistor 10 14 VCC Amplifier Shutdown Amplifier Negative Input Digital Supply. Bypass with a 0.1µF capacitor to GND. Detailed Description Digital Interface Operation The MAX5436–MAX5439 use a 3-wire SPI/QSPI/ MICROWIRE-compatible serial data interface to control the wiper position. This write-only interface contains three inputs: chip select (CS), data in (DIN), and serial clock (SCLK). When CS is taken low, data from DIN is synchronously loaded into the serial shift register on the rising edge of each SCLK pulse (Figure 2). The 8-bit data word requires 8 clock pulses to input the serial data. Note that the first bit of the data word, D7, is unused and should be ignored. Therefore, the second rising edge of SCLK loads the MSB. After all the data bits have been shifted in, they are latched into the potentiometer control register when CS transitions from low to high, the wiper position is then updated. Note that if CS is not kept low during the entire data stream, the data will be corrupted and the device will need to be reloaded. Adjustable Gain Amplifier The MAX5436/MAX5438 are used with the MAX427 to make a digitally adjustable gain circuit as shown in Figure 4. The normal feedback resistor is replaced with the MAX5436/MAX5438 in a variable-resistor configuration so that the gain of the circuit can be digitally controlled. The MAX5437/MAX5439 can use the internal high-voltage amplifier to make this digitally adjustable gain circuit. LCD Biasing Control Applications The MAX5436–MAX5439 are ideal for LCDs that require separate voltage for contrast control in addition to the main supply voltage. Figure 5a shows the MAX5436– MAX5439 being used for LCD contrast control along with the MAX629, which provides the LCD supply voltage. A similar circuit with an additional buffer circuit is shown in Figure 5b. Applications Information Power-Up Sequencing The MAX5436–MAX5439 have been designed so that any of the supplies can turn on first without causing any unwanted crowbar currents to flow. Note that both digital and analog supplies are required to power up the wiper and uncommitted amplifier (MAX5437/MAX5439 only). _______________________________________________________________________________________ 7 MAX5436–MAX5439 Pin Description MAX5436–MAX5439 ±15V, 128-Tap, Low-Drift Digital Potentiometers DATA WORD D7 D6 D5 Don’t Care (MSB) D4 D3 D2 D1 D0 (LSB) First Bit Loaded Last Bit Loaded Figure 1. Serial Data Format WIPER POSITION UPDATED CS SCLK MSB LOADED DIN D7 D6 LAST BIT LOADED D5 D4 D3 D2 D1 MSB D0 LSB TIME Figure 2. Serial Interface Timing Diagram CS tCSW tCS1 tCSS tCSO tCL tCH tCP tCSH SCLK tDS tDH DIN Figure 3. Detailed Serial Interface Timing Diagram 8 _______________________________________________________________________________________ ±15V, 128-Tap, Low-Drift Digital Potentiometers MAX5436–MAX5439 +15V VS VO MAX427 -15V L R2 H MAX5436– MAX5439 R1 W VO/VS = 1 + R2/R1 Figure 4. Noninverting Amplifier VBATT DC/DC CONVERTER (SIMPLIFIED) VOUT (LCD BIAS) CONTROL FIXED ±28V IN LCD PANEL MAX5436– MAX5439 MAX629 ±16V TO ±26V CONTRAST ADJUST MICROCONTROLLER/MICROPROCESSOR Figure 5a. Simplified LCD Contrast Control Circuit VBATT DC/DC CONVERTER (SIMPLIFIED) VOUT (LCD BIAS) CONTROL FIXED ±28V IN LCD PANEL MAX629 MAX5437/ MAX5439 ±16V TO ±26V CONTRAST ADJUST MICROCONTROLLER/MICROPROCESSOR Figure 5b. Simplified LCD Contrast Control Circuit with Buffer _______________________________________________________________________________________ 9 MAX5436–MAX5439 ±15V, 128-Tap, Low-Drift Digital Potentiometers Functional Diagrams VCC VCC R 7 DIN SCLK CS 7-BIT SHIFT REGISTER CLOCK LOGIC H R 7-BIT LATCH R 7 DECODE 128 L POR MAX5436/ MAX5438 7 W VDD VSS DIN 7 DECODE 128 SCLK CLOCK LOGIC W L MAX5437/ MAX5439 CS GND 7-BIT SHIFT REGISTER H R 7-BIT LATCH VDD VSS POR GND OUT IN+ IN- SHDN Chip Information TRANSISTOR COUNT: 2556 PROCESS: BiCMOS 10 ______________________________________________________________________________________ ±15V, 128-Tap, Low-Drift Digital Potentiometers 10LUMAX.EPS e 4X S 10 MAX DIM MIN 0.043 A 0.006 A1 0.002 A2 0.030 0.037 0.120 D1 0.116 0.118 D2 0.114 0.120 E1 0.116 0.118 E2 0.114 0.199 H 0.187 L 0.0157 0.0275 L1 0.037 REF b 0.007 0.0106 e 0.0197 BSC c 0.0035 0.0078 0.0196 REF S α 0∞ 6∞ H ÿ 0.50±0.1 0.6±0.1 1 1 0.6±0.1 BOTTOM VIEW TOP VIEW D2 MILLIMETERS INCHES 10 MAX MIN 1.10 0.15 0.05 0.75 0.95 3.05 2.95 3.00 2.89 3.05 2.95 2.89 3.00 4.75 5.05 0.40 0.70 0.940 REF 0.177 0.270 0.500 BSC 0.090 0.200 0.498 REF 0∞ 6∞ E2 GAGE PLANE A2 c A b D1 A1 α FRONT VIEW E1 L L1 SIDE VIEW PROPRIETARY INFORMATION TITLE: PACKAGE OUTLINE, 10L uMAX/uSOP APPROVAL DOCUMENT CONTROL NO. REV. I 1 1 TSSOP4.40mm.EPS 21-0061 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. Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________ 11 © 2002 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products. MAX5436–MAX5439 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.)