Datasheet

ManualsBrandsMAXIM INTEGRATED ManualsData collecting ICsData acquisition IC - Digital potentiometer linear Permanent TQFN 16

General Description

The MAX5494–MAX5499 10-bit (1024-tap), dual, non-

volatile, linear-taper, programmable voltage-dividers

and variable resistors perform the function of a

mechanical potentiometer, but replace the mechanics

with a 3-wire SPI™-compatible serial interface. The

MAX5494/MAX5495 are dual, 3-terminal, programma-

ble voltage-dividers; the MAX5496/MAX5497 are dual,

2-terminal variable resistors; and the MAX5498/

MAX5499 include one 2-terminal variable resistor and

one 3-terminal programmable voltage-divider.

The MAX5494–MAX5499 feature an internal, nonvolatile,

electrically erasable programmable read-only memory

(EEPROM) that stores the wiper position for initialization

during power-up. The 3-wire SPI-compatible serial inter-

face allows communication at data rates up to 7MHz.

The MAX5494–MAX5499 are ideal for applications requir-

ing digitally controlled potentiometers. End-to-end resis-

tance values of 10kΩ and 50kΩ are available with a

35ppm/°C end-to-end temperature coefficient. The ratio-

metric temperature coefficient is 5ppm/°C for each chan-

nel, making these devices ideal for applications requiring

low-temperature-coefficient programmable voltage-

dividers such as low-drift, programmable-gain amplifiers.

The MAX5494–MAX5499 operate with either a single

power supply (+2.7V to +5.25V) or dual power supplies

(±2.5V). The devices consume 400µA (max) of supply

current when writing data to the nonvolatile memory

and 1.5µA (max) of standby supply current. The

devices are available in space-saving (5mm x 5mm x

0.8mm), 16-pin TQFN package and are specified over

the extended (-40°C to +85°C) temperature range.

Applications

Gain and Offset Adjustment

LCD Contrast Adjustment

Pressure Sensors

Low-Drift Programmable-Gain Amplifiers

Mechanical Potentiometer Replacement

Volume Control

Features

♦ Wiper Position Stored in Nonvolatile Memory and

Recalled Upon Power-Up

♦ 16-Pin, 5mm x 5mm x 0.8mm TQFN Package

♦ 35ppm/°C End-to-End Resistance Temperature

Coefficient

♦ 5ppm/°C Ratiometric Temperature Coefficient

♦ 10kΩ and 50kΩ End-to-End Resistor Values

♦ 3-Wire SPI-Compatible Serial Interface

♦ Reliability (T

= +85°C)

50,000 Wiper Store Cycles

50 Years Wiper Data Retention

♦ 1.5µA (max) Standby Current

♦ Single +2.7V to +5.25V Supply Operation

♦ Dual ±2.5V Supply Operation

MAX5494–MAX5499

10-Bit, Dual, Nonvolatile, Linear-Taper

Digital Potentiometers

________________________________________________________________

Maxim Integrated Products

1234

12 11 10 9

SCLK

N.C.

DIN

GNDINTERFACE

N.C.

TOP VIEW

MAX5494

MAX5495

5mm × 5mm × 0.8mm TQFN

1234

12 11 10 9

SCLK

N.C.

DIN

GNDINTERFACE

D.N.C.

N.C.

MAX5496

MAX5497

5mm × 5mm × 0.8mm TQFN

PART TEMP RANGE

PIN-

PACKAGE

PKG CODE

MAX5494ETE -40°C to +85°C 16 TQFN-EP* T1655-2

MAX5495ETE -40°C to +85°C 16 TQFN-EP* T1655-2

Pin Configurations

Ordering Information

19-3562; Rev 2; 1/06

For pricing delivery, and ordering information please contact Maxim Direct at 1-888-629-4642,

or visit Maxim’s website at www.maxim-ic.com.

EP = Exposed pad.

Ordering Information continued at end of data sheet.

Selector Guide appears at end of data sheet.

Pin Configurations continued at end of data sheet.

EVALUATION KIT

AVAILABLE

SPI is a trademark of Motorola, Inc.

Summary of content (20 pages)

PAGE 1
9-3562; Rev 2; 1/06 KIT ATION EVALU E L B AVAILA 10-Bit, Dual, Nonvolatile, Linear-Taper Digital Potentiometers Features The MAX5494–MAX5499 10-bit (1024-tap), dual, nonvolatile, linear-taper, programmable voltage-dividers and variable resistors perform the function of a mechanical potentiometer, but replace the mechanics with a 3-wire SPI™-compatible serial interface.
PAGE 2
MAX5494–MAX5499 10-Bit, Dual, Nonvolatile, Linear-Taper Digital Potentiometers ABSOLUTE MAXIMUM RATINGS VDD to GND ...........................................................-0.3V to +6.0V VSS to GND............................................................-3.5V to +0.3V VDD to VSS .............................................................-0.3V to +6.0V H1, H2, L1, L2, W1, W2 to VSS.........(VSS - 0.3V) to (VDD + 0.3V) CS, SCLK, DIN to GND ..............................-0.3V to (VDD + 0.
PAGE 3
10-Bit, Dual, Nonvolatile, Linear-Taper Digital Potentiometers (VDD = +2.7V to +5.25V, VSS = GND = 0, VH_ = VDD, VL_ = 0, TA = -40°C to +85°C, unless otherwise noted. Typical values are at VDD = +5.0V, TA = +25°C.) (Note 1) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS DC PERFORMANCE (MAX5496–MAX5499 Variable Resistor) Resolution N 10 VDD = 2.7V Integral Nonlinearity (Note 3) INL_R -1.6 VDD = 3V -4 -1.4 +4 VDD = 5V -4 -1.3 +4 VDD = 2.
PAGE 4
MAX5494–MAX5499 10-Bit, Dual, Nonvolatile, Linear-Taper Digital Potentiometers ELECTRICAL CHARACTERISTICS (continued) (VDD = +2.7V to +5.25V, VSS = GND = 0, VH_ = VDD, VL_ = 0, TA = -40°C to +85°C, unless otherwise noted. Typical values are at VDD = +5.0V, TA = +25°C.) (Note 1) PARAMETER SYMBOL CONDITIONS MIN MAX5494/MAX5498; VDD = 3V; wiper at code 495; 10kHz, 1VRMS signal is applied at H_; 10pF load at wiper Total Harmonic Distortion TYP MAX 0.
PAGE 5
10-Bit, Dual, Nonvolatile, Linear-Taper Digital Potentiometers (VDD = +2.7V to +5.25V, VSS = GND = 0, VH_ = VDD, VL_ = 0, TA = -40°C to +85°C, unless otherwise noted. Typical values are at VDD = +5.0V, TA = +25°C.
PAGE 6
Typical Operating Characteristics (VDD = +5.0V, VSS = 0, TA = +25°C, unless otherwise noted.) VDD = 3V 1.0 0.8 0.6 0.4 0.2 0 DNL (LSB) 0.5 INL (LSB) 0 -0.2 -0.5 -0.4 -0.6 0 -0.2 -0.4 -0.6 -1.0 -0.8 -0.8 -1.0 -1.5 -1.0 0 0 128 256 384 512 640 768 896 1024 2.5 128 256 384 512 640 768 896 1024 3.0 3.5 4.0 4.5 CODE CODE VDD (V) MAXIMUM INTEGRAL NONLINEARITY vs. SUPPLY VOLTAGE (VARIABLE RESISTOR) DIFFERENTIAL NONLINEARITY vs. CODE (VOLTAGE-DIVIDER) INTEGRAL NONLINEARITY vs.
PAGE 7
10-Bit, Dual, Nonvolatile, Linear-Taper Digital Potentiometers END-TO-END RESISTANCE (RHL) % CHANGE vs. TEMPERATURE (VOLTAGE-DIVIDER) 19 18 17 0.4 0.2 0 -0.2 -0.4 -0.6 -0.8 -1.0 16 0 1 2 3 4 -15 STANDBY SUPPLY CURRENT vs. TEMPERATURE 0.4 0.2 0 -0.2 -0.4 -0.6 -0.8 10 35 60 85 -40 0.6 VDD = 5V 1000 100 160 120 100 80 60 40 10kΩ 35 60 85 TEMPERATURE (°C) VARIABLE RESISTOR TEMPERATURE COEFFICIENT vs.
PAGE 8
Typical Operating Characteristics (continued) (VDD = +5.0V, VSS = 0, TA = +25°C, unless otherwise noted.) CROSSTALK CROSSTALK vs. FREQUENCY VW2 2V/div 0 MAX5494 toc20 MAX5494 toc19 CW_ = 10pF CODE = 01111 01111 VW1 20mV/div CROSSTALK (dB) -20 VH2 = VDD VL2 = VL1 = VH1 = GND CW_ = 10pF -40 -60 -80 MAX5494/MAX5498 -100 MAX5495/MAX5499 -120 400ns/div 0.01 0.1 1 10 100 1000 FREQUENCY (kHz) THD+N vs. FREQUENCY (MAX5495/MAX5499) THD+N vs.
PAGE 9
10-Bit, Dual, Nonvolatile, Linear-Taper Digital Potentiometers PIN MAX5494/ MAX5495 MAX5496/ MAX5497 MAX5498/ MAX5499 NAME FUNCTION 1 1 1 CS Active-Low Chip-Select Input. Drive CS low to enable the serial interface. Drive CS high to disable the serial interface and put the device in standby mode. 2 2 2 W2 Wiper Terminal 2 3 3 3 L2 Low Terminal 2 4 — — H2 High Terminal 2 5 5 5 VDD Positive Power-Supply Input. 2.7V ≤ VDD ≤ 5.25V. Bypass with a 0.
PAGE 10
-Bit, Dual, Nonvolatile, Linear-Taper Digital Potentiometers MAX5494–MAX5499 Functional Diagrams H1 VDD GND VSS CS SCLK DIN POR 2 x 10 BIT NVM 10-BIT LATCH 10 10-BIT LATCH 10 DECODER 1024 TAPS W1 SPI INTERFACE L1 H2 MAX5494 MAX5495 DECODER 1024 TAPS W2 L2 NOTE: THE PROGRAMMABLE VOLTAGE-DIVIDER IS NOT INTENDED FOR CURRENT TO FLOW THROUGH THE WIPER. NOTE: SEE THE MAX5494/MAX5495/MAX5498/MAX5499 PROGRAMMABLE VOLTAGE-DIVIDERS SECTION. Figure 1.
PAGE 11
10-Bit, Dual, Nonvolatile, Linear-Taper Digital Potentiometers VDD GND VSS 2 x 10 BIT NVM POR CS SCLK DIN 10-BIT LATCH 10 DECODER 1024 TAPS W1 L1 SPI INTERFACE 10-BIT LATCH 10 DECODER MAX5496 MAX5497 1024 TAPS W2 L2 Figure 2.
PAGE 12
Detailed Description The MAX5494–MAX5499 dual, nonvolatile, linear-taper, programmable voltage-dividers and variable resistors feature 1024 tap points (10-bit resolution) (see the Functional Diagrams). These devices consist of multiple strings of equal resistor segments with a wiper contact that moves among the 1024 effective tap points by a 3-wire SPI-compatible serial interface.
PAGE 13
10-Bit, Dual, Nonvolatile, Linear-Taper Digital Potentiometers D RWL (D) = × RW−L + RZ 1023 where D is decimal equivalent of the 10 data bits written, RW-L is the nominal end-to-end resistance, and RZ is the zero-scale error. Table 1 shows RWL at selected codes. either eight clock cycles to transfer the command bits (Figure 7b) or 24 clock cycles with 16 bits disregarded by the device (Figure 7a).
PAGE 14
MAX5494–MAX5499 10-Bit, Dual, Nonvolatile, Linear-Taper Digital Potentiometers a) 24-BIT COMMAND/DATA WORD CS SCLK 1 2 3 4 5 6 8 9 RA1 RA0 D9 C1 C0 DIN 7 10 11 12 13 14 15 16 17 18 D8 D7 D6 D5 D4 D3 D2 D1 D0 19 20 21 22 23 24 b) 8-BIT COMMAND WORD CS SCLK 1 2 DIN 3 4 5 6 C1 C0 7 8 RA1 RA0 Figure 7. SPI-Compatible Serial-Interface Format Table 2.
PAGE 15
10-Bit, Dual, Nonvolatile, Linear-Taper Digital Potentiometers Write NV Register The “write NV register” command (C1, C0 = 01) stores the position of the wiper to the NV registers for use at power-up. Alternatively, the “copy wiper register to NV register” command writes to the NV register. Writing to the NV register does not affect the position of the wipers. The operation takes up to 12ms (max) after CS goes high to complete and no other operation should be performed until completion.
PAGE 16
MAX5494–MAX5499 10-Bit, Dual, Nonvolatile, Linear-Taper Digital Potentiometers Copy NV Register to Wiper Register The “copy NV register to wiper register” (C1, C0 = 11) restores the wiper position to the current value stored in the NV register. Figure 11 shows how to copy data from NV register 1 to wiper register 1. Standby Mode The MAX5494–MAX5499 feature a low-power standby mode. When the device is not being programmed, it enters into standby mode and supply current drops to 0.6µA (typ).
PAGE 17
10-Bit, Dual, Nonvolatile, Linear-Taper Digital Potentiometers R1 R2 1 fC = 2π × R3 × C G = 1+ Programmable Filter Figure 14 shows the configuration for 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). Gain and Offset Voltage Adjustment Figure 15 shows an application using the MAX5498/ MAX5499 to adjust the gain and nullify the offset voltage.
PAGE 18
Selector Guide PART END-TO-END RESISTANCE (kΩ) CONFIGURATION MAX5494ETE Two programmable voltagedividers 10 MAX5495ETE Two programmable voltagedividers 50 MAX5496ETE Two variable resistors 10 MAX5497ETE Two variable resistors 50 MAX5498ETE One programmable voltagedivider and one variable resistor 10 MAX5499ETE One programmable voltagedivider and one variable resistor 50 Ordering Information (continued) PART PINPACKAGE TEMP RANGE MAX5496ETE -40°C to +85°C 16 TQFN-EP* T1655-2 -40°C
PAGE 19
10-Bit, Dual, Nonvolatile, Linear-Taper Digital Potentiometers QFN THIN.EPS ______________________________________________________________________________________ 19 MAX5494–MAX5499 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.
PAGE 20
MAX5494–MAX5499 10-Bit, Dual, Nonvolatile, Linear-Taper Digital Potentiometers 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.) Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied.