Dual, 256-Tap, Volatile, Low-Voltage Linear Taper Digital Potentiometers

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1 EVAUATION KIT AVAIABE MAX5386/MAX5388 General Description The MAX5386/MAX5388 dual, 256-tap, volatile, low- voltage linear taper digital potentiometers offer three endto-end resistance values of 1kΩ, 5kΩ, and 1kΩ. Operating from a single +2.6V to +5.5V power supply these devices provide a low 35ppm/ C end-to-end temperature coefficient. The devices feature an SPI interface. The small package size, low supply voltage, low supply current, and automotive temperature range of the MAX5386/MAX5388 make the devices uniquely suitable for the portable consumer market and battery-backup industrial applications. The MAX5386 includes two digital potentiometers in a voltage-divider configuration. The MAX5388 includes one digital potentiometer in a voltage-divider configuration and one digital potentiometer in a variable-resistor configuration. The MAX5386/MAX5388 are specified over an extended -4 C to +125 C temperature range and are available in 16-pin, 3mm x 3mm TQFN or 1-pin, 3mm x 5mm µmax packages, respectively. Applications ow-voltage Battery Applications Portable Electronics Mechanical Potentiometer Replacement Offset and Gain Control Adjustable Voltage References/inear Regulators Functional Diagrams appear at end of data sheet. Pin Configurations Features Dual, 256-Tap, inear Taper Positions Single +2.6V to +5.5V Supply Operation ow (< 1μA) Quiescent Supply Current 1kΩ, 5kΩ, 1kΩ End-to-End Resistance Values SPI-Compatible Interface Power-On Sets iper to Midscale -4 C to +125 C Operating Temperature Range Ordering Information PART Note: All devices are specified over the -4 C to +125 C operating temperature range. +Denotes a lead(pb)-free/ros-compliant package. *EP = Exposed pad. PIN- PACKAGE END-TO-END RESISTANCE (kω) MAX5386ATE+ 16 TQFN-EP* 1 MAX5386MATE+ 16 TQFN-EP* 5 MAX5386NATE+ 16 TQFN-EP* 1 MAX5388AUB+ 1 µmax 1 MAX5388MAUB+ 1 µmax 5 MAX5388NAUB+ 1 µmax 1 μmax is a registered trademark of Maxim Integrated Products, Inc. TOP VIE N.C. A A A VDD B B N.C. SCK DIN MAX5386 *EP 4 B I.C N.C. N.C. GND TOP VIE GND B B B MAX5388 µmax A A V DD SCK DIN *EP = EXPOSED PAD. TQFN ; Rev 3; 9/14

2 Absolute Maximum Ratings V DD to GND...-.3V to +6V _, _, _ to GND...-.3V to the lower of (V DD +.3V) and +6V All Other Pins to GND...-.3V to +6V Continuous Current in to _, _, and _ MAX5386/MAX ±5mA MAX5386M/MAX5388M...±2mA MAX5386N/MAX5388N...±1mA Continuous Power Dissipation (T A = +7 C) 16 TQFN (derate 14.7m/ C above+7 C) m 1 µmax (derate 8.8m/ C above+7 C) m Operating Temperature Range...-4 C to +125 C Junction Temperature C Storage Temperature Range C to +15 C ead Temperature (soldering, 1s)...+3 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 = +2.6V to +5.5V, V _ = V DD, V _ = GND, T A = T MIN to T MAX, unless otherwise noted. Typical values are at V DD = +5V, T A = +25 C. ) (Note 1) PARAMETER SYMBO CONDITIONS MIN TYP MAX UNITS Resolution N 256 Tap DC PERFORMANCE (VOTAGE-DIVIDER MODE) Integral Nonlinearity IN (Note 2) SB Differential Nonlinearity DN (Note 2) SB Dual Code Matching Register A = register B SB Ratiometric Resistor Tempco ( V /V )/ T no load ±5 ppm/ C Full-Scale Error Zero-Scale Error Code = FF Code = DC PERFORMANCE (VARIABE-RESISTOR MODE) (Note 3) Integral Nonlinearity R-IN V DD > +2.6V V DD > +4.75V MAX5386/MAX MAX5386M/MAX5388M MAX5386N/MAX5388N MAX5386/MAX MAX5386M/MAX5388M MAX5386N/MAX5388N MAX5386/MAX5388 ±1. ±2.5 MAX5386M/MAX5388M ±.5 ±1. MAX5386N/MAX5388N ±.25 ±.8 MAX5386/MAX5388 ±.4 ±1.5 MAX5386M/MAX5388M ±.3 ±.75 MAX5386N/MAX5388N ±.25 ±.5 Differential Nonlinearity R-DN V DD 2.6V SB DC PERFORMANCE (RESISTOR CARACTERISTI) V DD 2.6V 25 6 iper Resistance (Note 4) R V DD > 4.75V 15 2 Terminal Capacitance C _, C _ Measured to GND 1 pf iper Capacitance C _ Measured to GND 5 pf End-to-End Resistor Tempco TC R No load 35 ppm/ C End-to-End Resistor Tolerance R iper not connected % AC PERFORMANCE Crosstalk (Note 5) -9 db -3dB Bandwidth B Code = 8, 1pF load, V DD = +2.6V MAX5386/MAX MAX5386M/MAX5388M 15 MAX5386N/MAX5388N 75 SB SB SB Ω kz Maxim Integrated 2

3 Electrical Characteristics (continued) (V DD = +2.6V to +5.5V, V _ = V DD, V _ = GND, T A = T MIN to T MAX, unless otherwise noted. Typical values are at V DD = +5V, T A = +25 C. ) (Note 1) PARAMETER SYMBO CONDITIONS MIN TYP MAX UNITS Total armonic Distortion Plus Noise TD+N Measured at, V _ = 1V RMS at 1kz.15 % iper Settling Time (Note 6) t S MAX5386M/MAX5388M 1 MAX5386/MAX POER SUPPIES MAX5386N/MAX5388N 2 Supply Voltage Range V DD V Standby Current Digital inputs = V DD or GND 1 µa DIGITA INPUTS Minimum Input igh Voltage V I 7 %V DD Maximum Input ow Voltage V I 3 %V DD Input eakage Current µa Input Capacitance 5 pf TIMING CARACTERISTI (Note 7) Maximum SCK Frequency f MAX 1 Mz SCK Clock Period t CP 1 ns SCK Pulse-idth igh t C 4 ns SCK Pulse-idth ow t C 4 ns Fall to SCK Rise Setup Time t S 4 ns SCK Rise to Rise old Time t ns DIN Setup Time t DS 4 ns DIN old Time t D ns SCK Rise to Fall Delay t 1 ns SCK Rise to SCK Rise old Time t 1 4 ns Pulse-idth igh t 1 ns Note 1: All devices are 1% production tested at T A = +25 C. Specifications over temperature limits are guaranteed by design and characterization. Note 2: DN and IN are measured with the potentiometer configured as a voltage-divider (Figure 1) with = V DD and = GND. The wiper terminal is unloaded and measured with an ideal voltmeter. Note 3: R-DN and R-IN are measured with the potentiometer configured as a variable resistor (Figure 1). DN and IN are measured with the potentiometer configured as a variable resistor. _ is unconnected and _ = GND. For V DD = +5V, the wiper terminal is driven with a source current of 4μA for the 1kΩ configuration, 8μA for the 5kΩ configuration, and 4μA for the 1kΩ configuration. For V DD = +2.6V, the wiper terminal is driven with a source current of 2μA for the 1kΩ configuration, 4μA for the 5kΩ configuration, and 2μA for the 1kΩ configuration. Note 4: The wiper resistance is the worst value measured by injecting the currents given in Note 3 in to with = GND. R = (V - V )/I. Note 5: Drive A with a 1kz GND to V DD amplitude tone. A = B = GND. No load. B is at midscale with a 1pF load. Measure B. Note 6: The wiper-settling time is the worst case to 5% rise time, measured between tap and tap 127. = V DD, = GND, and the wiper terminal is loaded with 1pF capacitance to ground. Note 7: Digital timing is guaranteed by design and characterization, not production tested. ns Maxim Integrated 3

4 Typical Operating Characteristics (V DD = 5V, T A = +25 C, unless otherwise noted.) SUPPY CURRENT (µa) SUPPY CURRENT vs. TEMPERATURE V DD = 2.6V V DD = 5V MAX5386 toc1 SUPPY CURRENT (ma) SUPPY CURRENT vs. DIGITA INPUT VOTAGE V DD = 5V V DD = 2.6V MAX5386 toc2 IDD (µa) SUPPY CURRENT vs. SUPPY VOTAGE MAX5386 toc TEMPERATURE ( C) DIGITA INPUT VOTAGE (V) V DD (V) , 1, -TO- RESISTANCE (kω) RESISTANCE ( TO ) vs. (1kΩ) MAX5386 toc4 -TO- RESISTANCE (kω) 55, 5, 45, 4, 35, 3, 25, 2, 15, 1, RESISTANCE ( TO ) vs. (5kΩ) MAX5386 toc5 RESISTANCE (-TO-) (kω) 11k 1k 9k 8k 7k 6k 5k 4k 3k 2k RESISTANCE (-TO-) vs. (1kΩ) MAX5386 toc k IPER RESISTANCE (Ω) IPER RESISTANCE vs. IPER VOTAGE (1kΩ) V DD = 5V V DD = 2.6V MAX5386 toc7 END-TO-END RESISTANCE % CANGE END-TO-END RESISTANCE % CANGE vs. TEMPERATURE 1kΩ 1kΩ 5kΩ MAX5386 toc8 DN (SB) VARIABE-RESISTOR DN vs. (1kΩ) I IPER = 4µA MAX5386 toc IPER VOTAGE TEMPERATURE ( C) Maxim Integrated 4

5 Typical Operating Characteristics (continued) (V DD = 5V, T A = +25 C, unless otherwise noted.) VARIABE-RESISTOR DN vs. (5kΩ) I IPER = 8µA MAX5386 toc VARIABE-RESISTOR DN vs. (1kΩ) I IPER = 4µA MAX5386 toc VARIABE-RESISTOR IN vs. (1kΩ) I IPER = 4µA MAX5386 toc DN (SB) DN (SB) IN (SB) VARIABE-RESISTOR IN vs. (5kΩ) I IPER = 8µA MAX5386 toc VARIABE-RESISTOR IN vs. (1kΩ) I IPER = 4µA MAX5386 toc VOTAGE-DIVIDER DN vs. (1kΩ) MAX5386 toc IN (SB) IN (SB) DN (SB) VOTAGE-DIVIDER DN vs. (5kΩ) MAX5386 toc VOTAGE-DIVIDER DN vs. (1kΩ) MAX5386 toc VOTAGE-DIVIDER IN vs. (1kΩ) MAX5386 toc DN (SB) DN (SB) IN (SB) Maxim Integrated 5

6 Typical Operating Characteristics (continued) (V DD = 5V, T A = +25 C, unless otherwise noted.) VOTAGE-DIVIDER IN vs. (5kΩ) MAX5386 toc VOTAGE-DIVIDER IN vs. (1kΩ) MAX5386 toc2 TAP-TO-TAP SITCING TRANSIENT (CODE 127 TO 128) (MAX5386) MAX5386 toc21 IN (SB) IN (SB) V - 2mV/div V/div ns/div TAP-TO-TAP SITCING TRANSIENT (CODE 128 TO 128) (MAX5386M) MAX5386 toc22 TAP-TO-TAP SITCING TRANSIENT (CODE 127 TO 128) (MAX5386N) MAX5386 toc23 MAX5386 POER-ON IPER TRANSIENT CODE TO 128 MAX5386 toc24 V - 2mV/div V - 2mV/div OUTPUT 2V/div 5V/div 5V/div V DD 2V/div 4ns/div 1µs/div 2µs/div GAIN (db) MIDSCAE FREQUENCY RESPONSE V IN = 1V P-P C = 1pF MAX5386 MAX5386M MAX5386N MAX5386 toc25 CROSSTAK (db) CROSSTAK vs. FREQUENCY MAX5386 MAX5386N MAX5386M MAX5386 toc26 TD+N (%) TD+N vs. FREQUENCY MAX5386M MAX5386N MAX5386 MAX5386 toc , 1, FREQUENCY (kz) FREQUENCY (kz) FREQUENCY (kz) Maxim Integrated 6

7 Pin Description MAX5386 PIN MAX5388 NAME 1 3 B 2 4 B Resistor B iper Terminal 3 2 B FUNCTION Resistor B igh Terminal. The voltage at B can be higher or lower than the voltage at B. Current can flow in to or out of B. Resistor B ow Terminal. The voltage at B can be higher or lower than the voltage at B. Current can flow in to or out of B. 4 I.C. Internally Connected. Connect to GND. 5 1 GND Ground. Both pins must be grounded. 6, 7, 11, 13 N.C. No Connection. Not internally connected. 8 5 Active-ow Chip-Select Input 9 6 DIN Serial-Interface Data Input 1 7 SCK Serial-Interface Clock Input 12 8 V DD Power-Supply Input. Bypass V DD to GND with a.1µf capacitor close to the device. 14 A 15 9 A Resistor A iper Terminal 16 1 A Resistor A igh Terminal. The voltage at A can be higher or lower than the voltage at A. Current can flow in to or out of A. Resistor A ow Terminal. The voltage at A can be higher or lower than the voltage at A. Current can flow in to or out of A. EP Exposed Pad (TQFN Only). Internally connected to GND. Connect to ground. VOTAGE-DIVIDER CONFIGURATION VARIABE-RESISTOR CONFIGURATION N.C. Figure 1. Voltage-Divider/Variable-Resistor Configurations Maxim Integrated 7

8 Detailed Description The MAX5386/MAX5388 dual, 256-tap, volatile lowvoltage linear taper digital potentiometers offer three endtoend resistance values of 1kΩ, 5kΩ, and 1kΩ. Each potentiometer consists of 255 fixed resistors in series between terminals and. The potentiometer wiper,, is programmable to access anyone of the 256 tap points on the resistor string. The potentiometers in each device are programmable independently of each other. The MAX5386/MAX5388 have an SPI interface. SPI Digital Interface The MAX5386/MAX5388 include an SPI interface, which provides a 3-wire write-only serial data interface to control the wiper tap position through inputs chip select (), data in (DIN), and data clock (SCK). Drive low to load data from DIN synchronously into the serial shift register on the rising edge of each SCK pulse. The MAX5386/ MAX5388 load the last 9 bits of clocked data once transitions high. See Figures 2 and 3. After all the data bits are shifted in, data are latched into the appropriate potentiometer control register when goes from low to high. Data written to a memory register immediately updates the wiper position. Keep low during the entire data stream to prevent the data from being terminated. The first bit A (address bit) addresses one of the two potentiometers; writing a zero in A addresses control register A and writing a one in A addresses control register B. See Table 1. The power-on reset (POR) circuitry sets the wiper to midscale (D[7:] 1 ). The 8 data bits (D7 D) indicate the position of the wiper. For D[7:] =, the wiper moves to the position closest to. For D[7:] = , the wiper moves closest to. D[7:] is 1 following poweron for both registers A and B. Register A: The data byte writes to register A, and the wiper of potentiometer A moves to the appropriate position at the rising edge of. D[7:] indicates the position of the wiper. D[7:] = moves the wiper to the position closest to. D[7:] = moves the wiper to the position closest to. D[7:] is 1 following power-on. Register B: The data byte writes to register B, and the wiper of potentiometer B moves to the appropriate position at the rising edge of. D[7:] indicates the position of the wiper. D[7:] = moves the wiper to the position closest to. D[7:] = moves the wiper to the position closest to. D[7:] is 1 following power-on. Table 1. SPI Register Map Bit Number Bit Name A D7 D6 D5 D4 D3 D2 D1 D rite iper Register A D7 D6 D5 D4 D3 D2 D1 D rite iper Register B 1 D7 D6 D5 D4 D3 D2 D1 D Maxim Integrated 8

9 COMMAND STARTED 9 BITS IPER REGISTER OADED SCK DIN A D7 D6 D5 D4 D3 D2 D D1 Figure 2. SPI Digital Interface Format t t 1 t O ts t C t C t CP t t D SCK t DS DIN Figure 3. SPI Timing Diagram Maxim Integrated 9

10 Applications Information Variable-Gain Amplifier Figure 4 shows a potentiometer adjusting the gain of a noninverting amplifier. Figure 5 shows a potentiometer adjusting the gain of an inverting amplifier. Adjustable Dual inear Regulator Figure 6 shows an adjustable dual linear regulator using a dual potentiometer as two variable resistors. Adjustable Voltage Reference Figure 7 shows an adjustable voltage reference circuit using a potentiometer as a voltage-divider. OUT1 OUT2 V OUT1 V OUT2 V IN V OUT V+ MAX8866 IN SET1 SET2 Figure 4. Variable-Gain Noninverting Amplifier Figure 6. Adjustable Dual inear Regulator +5V V IN IN OUT MAX616 V REF V OUT GND Figure 5. Variable-Gain Inverting Amplifier Figure 7. Adjustable Voltage Reference Maxim Integrated 1

11 Variable Gain Current to Voltage Converter Figure 8 shows a variable gain current-to-voltage converter using a potentiometer as a variable resistor. CD Bias Control Figure 9 shows a positive CD bias control circuit using a potentiometer as a voltage-divider. Programmable Filter Figure 1 shows a programmable filter using a dual potentiometer. Offset Voltage Adjustment Circuit Figure 11 shows an offset voltage adjustment circuit using a dual potentiometer. R3 VIN B R3 B B VOUT R1 R2 R1 IS A VOUT A R2 VOUT = IS x ((R3 x (1 + R2/R1)) + R2) A Figure 8. Variable Gain I-to-V Converter Figure 1. Programmable Filter +5V A +5V A A +3V VOUT VOUT B B B Figure 9. Positive CD Bias Control Using a Voltage-Divider Figure 11. Offset Voltage Adjustment Circuit Maxim Integrated 11

12 Functional Diagrams A A A V DD MAX5386 B 256 DECODER ATC SCK POR SPI B 256 DECODER ATC DIN B GND A A V DD MAX5388 B 256 DECODER ATC SCK POR SPI B 256 DECODER ATC DIN B GND Chip Information PROCESS: BiCMOS Package Information For the latest package outline information and land patterns (footprints), go to Note that a +, #, or - in the package code indicates RoS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoS status. PACKAGE TYPE PACKAGE CODE DOCUMENT NO. AND PATTERN NO. 1 µmax U TQFN-EP T Maxim Integrated 12

13 Revision istory REVISION NUMBER REVISION DATE DESCRIPTION PAGES CANGED 4/9 Initial release 1 11/9 Released MAX5386ATE+ and MAX5386NATE+ in Ordering Information; corrected specifications for Full-Scale Error, Zero-Scale Error, and Integral Nonlinearity in Electrical Characteristics; added I.C. row to Pin Description; corrected Figure 1 1, 2, 7 2 1/1 Released the MAX5388AUB+, MAX5388MAUB+, MAX5388NAUB+ + in Ordering Information. 3 9/14 Removed automotive reference from data sheet 1 1 For pricing, delivery, and ordering information, please contact Maxim Direct at , or visit Maxim Integrated s website at Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses are implied. Maxim Integrated reserves the right to change the circuitry and specifications without notice at any time. The parametric values (min and max limits) shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance. Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc. 214 Maxim Integrated Products, Inc. 13

14 Mouser Electronics Authorized Distributor Click to View Pricing, Inventory, Delivery & ifecycle Information: Maxim Integrated: MAX5386ATE+ MAX5386ATE+T MAX5386MATE+ MAX5386MATE+T MAX5386NATE+ MAX5386NATE+T MAX5388NAUB+ MAX5388AUB+ MAX5388AUB+T MAX5388MAUB+ MAX5388MAUB+T MAX5388NAUB+T

EVALUATION KIT AVAILABLE Dual, 256-Tap, Volatile, Low-Voltage Linear Taper Digital Potentiometers. S Dual, 256-Tap, Linear Taper Positions

EVALUATION KIT AVAILABLE Dual, 256-Tap, Volatile, Low-Voltage Linear Taper Digital Potentiometers. S Dual, 256-Tap, Linear Taper Positions 19-4599; Rev 2; 1/1 EVAUATION KIT AVAIABE Dual, 256-Tap, Volatile, ow-voltage General Description The dual, 256-tap, volatile, low-voltage linear taper digital potentiometers offer three end-to-end resistance