Rainbow Electronics MAX5489 User Manual

General Description

The MAX5487/MAX5488/MAX5489 dual, linear-taper,
digital potentiometers function as mechanical poten­tiometers with a simple 3-wire SPI™-compatible digital
interface that programs the wipers to any one of 256
tap positions. These digital potentiometers feature a
nonvolatile memory (EEPROM) to return the wipers to
their previously stored positions upon power-up.

The MAX5487 has an end-to-end resistance of 10kΩ,
while the MAX5488 and MAX5489 have resistances of
50kΩ and 100kΩ, respectively. These devices have a
low 35ppm/°C end-to-end temperature coefficient, and
operate from a single +2.7V to +5.25V supply.

The MAX5487/MAX5488/MAX5489 are available in a
16-pin 3mm x 3mm x 0.8mm thin QFN package. Each
device is guaranteed over the extended -40°C to +85°C
temperature range.

Applications

LCD Screen Adjustment

Audio Volume Control

Mechanical Potentiometer Replacement

Low-Drift Programmable Filters

Low-Drift Programmable-Gain Amplifiers

Features

♦ Wiper Position Stored in Nonvolatile Memory

(EEPROM) and Recalled Upon Power-Up or
Recalled by an Interface Command

♦ 3mm x 3mm x 0.8mm Thin QFN Package

♦ ±1 LSB INL, ±0.5 LSB DNL (Voltage-Divider Mode)

♦ 256 Tap Positions

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

Coefficient

♦ 5ppm/°C Ratiometric Temperature Coefficient

♦ 10kΩ, 50kΩ, and 100kΩ End-to-End Resistance

Values

♦ SPI-Compatible Serial Interface

♦ Reliability

200,000 Wiper Store Cycles
50-Year Wiper Data Retention

♦ +2.7V to +5.25V Single-Supply Operation

MAX5487/MAX5488/MAX5489

Dual, 256-Tap, Nonvolatile, SPI-Interface,

Linear-Taper Digital Potentiometers

________________________________________________________________ Maxim Integrated Products 1

19-3478; Rev 1; 1/05

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.

SPI is a trademark of Motorola, Inc.

Ordering Information/Selector Guide

PART TEMP RANGE PIN-PACKAGE

END-TO-END

RESISTANCE (kΩ)

TOP MARK

MAX5487ETE* -40°C to +85°C 16 Thin QFN-EP** 10 ABR

MAX5488ETE -40°C to +85°C 16 Thin QFN-EP** 50 ABS

MAX5489ETE -40°C to +85°C 16 Thin QFN-EP** 100 ABT

*Future product—contact factory for availability.
**EP = Exposed pad.

MAX5487
MAX5488
MAX5489

POR

8-BIT

LATCH

16-BIT

NV RAM

SCLK

DIN

CS

DECODER

8

8

256

DECODER

256

HA

WA

LA

HB

WB

LB

V

DD

GND

SPI

INTERFACE

8-BIT

LATCH

Functional Diagram

16

1

2

3

4

12

11

10

9

15 14 13

5678

N.C.

HA

WA

LA

HB

WB

LB

N.C.

SCLK

DIN

N.C.

N.C.

GND

N.C.

V

DD

TOP VIEW

EXPOSED PAD CONNECTED TO GND.

MAX5487
MAX5488
MAX5489

CS

THIN QFN

3mm × 3mm

Pin Configuration

MAX5487/MAX5488/MAX5489

Dual, 256-Tap, Nonvolatile, SPI-Interface,
Linear-Taper Digital Potentiometers

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

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.

VDDto GND...........................................................-0.3V to +6.0V

All Other Pins

to GND......................-0.3V to the lower of (V

DD

+ 0.3V) and +6.0V

Maximum Continuous Current into H_, W_, and L_

MAX5487......................................................................±5.0mA

MAX5488......................................................................±1.3mA

MAX5489......................................................................±0.6mA

Continuous Power Dissipation (T

A

= +70°C)

16-Pin Thin QFN (derate 17.5mW/°C above +70°C).....1398mW

Operating Temperature Range ...........................-40°C to +85°C

Junction Temperature......................................................+150°C

Storage Temperature Range .............................-60°C to +150°C

Lead Temperature (soldering, 10s) .................................+300°C

DC ELECTRICAL CHARACTERISTICS

(VDD= +2.7V to +5.25V, VH= VDD, VL= GND, TA= -40°C to +85°C, unless otherwise noted. Typical values are at VDD= +5.0V,
T

A

= +25°C, unless otherwise noted.) (Note 1)

PARAMETER

CONDITIONS

UNITS

DC PERFORMANCE (Voltage-Divider Mode, Figure 1)

Resolution N

Taps

Integral Nonlinearity INL (Note 2) ±1

LSB

Differential Nonlinearity DNL (Note 2)

LSB

Dual-Code Matching Register A = register B 2

LSB

End-To-End Resistor Tempco TC

R

35

ppm/°C

Ratiometric Resistor Tempco 5

ppm/°C

MAX5488

Full-Scale Error

MAX5489

LSB

MAX5488 0.6 1.5

Zero-Scale Error

MAX5489 0.3 1

LSB

DC PERFORMANCE (Variable-Resistor Mode, Figure 1)

Resolution

Taps

VDD = 5.0V

Integral Nonlinearity (Note 3) MAX5488/MAX5489

V

DD

= 3.0V ±3

VDD = 5.0V ±1

Differential Nonlinearity (Note 3) MAX5488/MAX5489

V

DD

= 3.0V ±1

LSB

DC PERFORMANCE (Resistor Characteristics)

VDD = 5.0V

350

Wiper Resistance (Note 4) R

W

VDD = 3.0V

675

Ω

Wiper Capacitance C

W

50 pF

MAX5487 7.5 10

MAX5488

50

End-to-End Resistance R

HL

MAX5489 75

100

125

kΩ

SYMBOL

MIN TYP MAX

256

±0.5

256

37.5

-0.6 +1.2

-0.3 +1.2

±1.5

200

325

12.5

62.5

MAX5487/MAX5488/MAX5489

Dual, 256-Tap, Nonvolatile, SPI-Interface,

Linear-Taper Digital Potentiometers

_______________________________________________________________________________________ 3

DC ELECTRICAL CHARACTERISTICS (continued)

(VDD= +2.7V to +5.25V, VH= VDD, VL= GND, TA= -40°C to +85°C, unless otherwise noted. Typical values are at VDD= +5.0V,
T

A

= +25°C, unless otherwise noted.) (Note 1)

PARAMETER

CONDITIONS

DIGITAL INPUTS

VDD = 3.6V to 5.25V 2.4

Input High Voltage (Note 5) V

IH

VDD = 2.7V to 3.6V

0.7 x

V

Input Low Voltage V

IL

VDD = 2.7V to 5.25V (Note 5) 0.8 V

Input Leakage Current I

IN

µA

Input Capacitance C

IN

5.0 pF

AC PERFORMANCE

Crosstalk

f

H_

= 1kHz, L_ = GND, measurement at W_

(Note 6)

-90 dB

MAX5488 90

-3dB Bandwidth BW

Wiper at midscale
C

W_

= 10pF

MAX5489 45

kHz

Total Harmonic Distortion THD

V

H_

= 1V

RMS

at 1kHz, L_ = GND,

measurement at W_

%

TIMING CHARACTERISTICS (Analog)

MAX5488

Wiper-Settling Time t

S

Code 0 to 127
(Note 7)

MAX5489 1.5

µs

TIMING CHARACTERISTICS (Digital, Figure 2, Note 8)

SCLK Frequency 5

SCLK Clock Period t

CP

ns

SCLK Pulse-Width High t

CH

80 ns

SCLK Pulse-Width Low t

CL

80 ns

CS Fall to SCLK Rise Setup t

CSS

80 ns

SCLK Rise to CS Rise Hold t

CSH

0ns

DIN to SCLK Setup t

DS

50 ns

DIN Hold after SCLK t

DH

0ns

SCLK Rise to CS Fall Delay t

CS0

20 ns

CS Rise to SCLK Rise Hold t

CS1

80 ns

CS Pulse-Width High t

CSW

ns

Write NV Register Busy Time t

BUSY

12 ms

Read NV Register Access Time t

ACC

1µs

W r i te W i p er Reg i ster to O utp ut D el ay

t

WO

1µs

NONVOLATILE MEMORY RELIABILITY

TA = +85°C50

Data Retention

Mil-Std-883 test
method 1008

T

A

= +125°C10

TA = +85°C 200,000

Endurance

Mil-Std-883 test
method 1033

T

A

= +125°C

SYMBOL

MIN TYP MAX UNITS

V

DD

200

200

±1.0

0.02

0.75

50,000

MHz

Years

Stores

MAX5487/MAX5488/MAX5489

Dual, 256-Tap, Nonvolatile, SPI-Interface,
Linear-Taper Digital Potentiometers

4 _______________________________________________________________________________________

Note 1: All devices are production tested at TA= +25°C and are guaranteed by design and characterization for -40°C < TA< +85°C.
Note 2: DNL and INL are measured with the potentiometer configured as a voltage-divider with H_ = V

DD

and L_ = 0. The wiper terminal

is unloaded and measured with an ideal voltmeter.

Note 3: DNL and INL are measured with the potentiometer configured as a variable resistor. H_ is unconnected and L_ = 0. For V

DD

=
+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. For V

DD

= +3V, the wiper terminal is driven with a source current of 200µA for the 10kΩ

configuration, 40µA for the 50kΩ configuration, and 20µA for the 100kΩ configuration.

Note 4: The wiper resistance is the worst value measured by injecting the currents given in Note 3 into W_ with L_ = GND. R

W

=

(V

W

- VH) / IW.

Note 5: The device draws higher supply current when the digital inputs are driven with voltages between (V

DD

- 0.5V) and (GND +

0.5V). See Supply Current vs. Digital Input Voltage in the Typical Operating Characteristics section.

Note 6: Wiper at midscale with a 10pF load.
Note 7: Wiper-settling time is the worst-case 0-to-50% rise time, measured between tap 0 and tap 127. H_ = V

DD

, 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 section).

Note 8: Digital timing is guaranteed by design and characterization, and is not production tested.

DC ELECTRICAL CHARACTERISTICS (continued)

(VDD= +2.7V to +5.25V, VH= VDD, VL= GND, TA= -40°C to +85°C, unless otherwise noted. Typical values are at VDD= +5.0V,
T

A

= +25°C, unless otherwise noted.) (Note 1)

PARAMETER

SYMBOL

CONDITIONS

MIN

TYP

MAX

UNITS

POWER SUPPLIES

Power-Supply Voltage V

DD

V

Supply Current I

DD

During write cycle only, digital inputs =
V

DD

or GND

400 µA

Standby Current Digital inputs = VDD or GND, TA = +25°C 0.5 1 µA

Figure 1. Voltage-Divider/Variable-Resistor Configurations

2.70 5.25

VOLTAGE-DIVIDER

CONFIGURATION

H

L

VARIABLE-RESISTOR

CONFIGURATION

W

H

L

MAX5487/MAX5488/MAX5489

Dual, 256-Tap, Nonvolatile, SPI-Interface,

Linear-Taper Digital Potentiometers

_______________________________________________________________________________________ 5

SUPPLY CURRENT vs. TEMPERATURE

MAX5487-89 toc01

TEMPERATURE (°C)

SUPPLY CURRENT (µA)

603510-15

0.2

0.4

0.6

0.8

1.0

1.2

0

-40 85

VCC = 5V

VCC = 3V

SUPPLY CURRENT

vs. DIGITAL INPUT VOLTAGE

MAX5487-89 toc02

DIGITAL INPUT VOLTAGE (V)

SUPPLY CURRENT (µA)

4321

1

10

100

1000

10,000

0

05

VCC = 5V

VCC = 3V

0

100

200

300

400

0 64 128 19232 96 160 224 256

WIPER RESISTANCE

vs. TAP POSITION (MAX5488)

MAX5487-89toc03

TAP POSITION

WIPER RESISTANCE (Ω)

TAP-TO-TAP SWITCHING TRANSIENT

(MAX5488)

MAX5487-89 toc04

1.0µs/div

WIPER

20mV/div

VH_ = 5.0V

CS

2.0V/div

TAP-TO-TAP SWITCHING TRANSIENT

(MAX5489)

MAX5487-89 toc05

1.0µs/div

WIPER

20mV/div

VH_ = 5.0V

CS

2.0V/div

WIPER TRANSIENT AT POWER-ON

MAX5487-89 toc06

2.0µs/div

WIPER

2.0V/div

VH_ = V

DD

V

DD

2.0V/div

Typical Operating Characteristics

(VDD= +5.0V, TA= +25°C, unless otherwise noted.)