19-3478; Rev 1; 1/05
Dual, 256-Tap, Nonvolatile, SPI-Interface,
Linear-Taper Digital Potentiometers
General Description
The MAX5487/MAX5488/MAX5489 dual, linear-taper,
digital potentiometers function as mechanical poten-
tiometers 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.
Features
o
Wiper Position Stored in Nonvolatile Memory
(EEPROM) and Recalled Upon Power-Up or
Recalled by an Interface Command
o
3mm x 3mm x 0.8mm Thin QFN Package
o
±1 LSB INL, ±0.5 LSB DNL (Voltage-Divider Mode)
o
256 Tap Positions
o
35ppm/°C End-to-End Resistance Temperature
Coefficient
o
5ppm/°C Ratiometric Temperature Coefficient
o
10kΩ, 50kΩ, and 100kΩ End-to-End Resistance
Values
o
SPI-Compatible Serial Interface
o
Reliability
200,000 Wiper Store Cycles
50-Year Wiper Data Retention
o
+2.7V to +5.25V Single-Supply Operation
SPI is a trademark of Motorola, Inc.
MAX5487/MAX5488/MAX5489
Applications
LCD Screen Adjustment
Audio Volume Control
Mechanical Potentiometer Replacement
Low-Drift Programmable Filters
Low-Drift Programmable-Gain Amplifiers
Ordering Information/Selector Guide
PART
MAX5487ETE*
MAX5488ETE
MAX5489ETE
TEMP RANGE
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
16 Thin QFN-EP**
16 Thin QFN-EP**
16 Thin QFN-EP**
END-TO-END
RESISTANCE (kΩ)
10
50
100
TOP MARK
ABR
ABS
ABT
*Future
product—contact factory for availability.
**EP
= Exposed pad.
Functional Diagram
N.C.
Pin Configuration
TOP VIEW
WA
14
HA
16
V
DD
SCLK
DIN
1
2
3
4
5
N.C.
6
N.C.
7
GND
8
N.C.
15
13
12 HB
11 WB
10 LB
9
N.C.
LA
V
DD
GND
SCLK
DIN
CS
8-BIT
LATCH
8
DECODER
256
SPI
INTERFACE
16-BIT
NV RAM
8-BIT
LATCH
8
DECODER
256
HA
WA
LA
POR
HB
MAX5487
MAX5488
MAX5489
CS
WB
MAX5487
MAX5488
MAX5489
LB
THIN QFN
3mm
×
3mm
EXPOSED PAD CONNECTED TO GND.
________________________________________________________________
Maxim Integrated Products
1
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.
Dual, 256-Tap, Nonvolatile, SPI-Interface,
Linear-Taper Digital Potentiometers
MAX5487/MAX5488/MAX5489
ABSOLUTE MAXIMUM RATINGS
V
DD
to 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
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.
DC ELECTRICAL CHARACTERISTICS
(V
DD
= +2.7V to +5.25V, V
H
= V
DD
, V
L
= GND, T
A
= -40°C to +85°C, unless otherwise noted. Typical values are at V
DD
= +5.0V,
T
A
= +25°C, unless otherwise noted.) (Note 1)
PARAMETER
Resolution
Integral Nonlinearity
Differential Nonlinearity
Dual-Code Matching
End-To-End Resistor Tempco
Ratiometric Resistor Tempco
Full-Scale Error
Zero-Scale Error
MAX5488
MAX5489
MAX5488
MAX5489
256
MAX5488/MAX5489
MAX5488/MAX5489
V
DD
= 5.0V
V
DD
= 3.0V
V
DD
= 5.0V
V
DD
= 3.0V
200
325
50
MAX5487
End-to-End Resistance
R
HL
MAX5488
MAX5489
7.5
37.5
75
10
50
100
12.5
62.5
125
kΩ
±1.5
±3
±1
±1
350
675
LSB
TC
R
SYMBOL
N
INL
DNL
(Note 2)
(Note 2)
Register A = register B
35
5
-0.6
-0.3
0.6
0.3
+1.2
+1.2
1.5
1
CONDITIONS
MIN
256
±1
±0.5
2
TYP
MAX
UNITS
Taps
LSB
LSB
LSB
ppm/°C
ppm/°C
LSB
LSB
DC PERFORMANCE (Voltage-Divider Mode, Figure 1)
DC PERFORMANCE (Variable-Resistor Mode, Figure 1)
Resolution
Integral Nonlinearity (Note 3)
Differential Nonlinearity (Note 3)
DC PERFORMANCE (Resistor Characteristics)
Wiper Resistance (Note 4)
Wiper Capacitance
R
W
C
W
V
DD
= 5.0V
V
DD
= 3.0V
Ω
pF
Taps
2
_______________________________________________________________________________________
Dual, 256-Tap, Nonvolatile, SPI-Interface,
Linear-Taper Digital Potentiometers
DC ELECTRICAL CHARACTERISTICS (continued)
(V
DD
= +2.7V to +5.25V, V
H
= V
DD
, V
L
= GND, T
A
= -40°C to +85°C, unless otherwise noted. Typical values are at V
DD
= +5.0V,
T
A
= +25°C, unless otherwise noted.) (Note 1)
PARAMETER
DIGITAL INPUTS
V
DD
= 3.6V to 5.25V
Input High Voltage (Note 5)
Input Low Voltage
Input Leakage Current
Input Capacitance
AC PERFORMANCE
Crosstalk
-3dB Bandwidth
Total Harmonic Distortion
TIMING CHARACTERISTICS (Analog)
Wiper-Settling Time
t
S
Code 0 to 127
(Note 7)
MAX5488
MAX5489
0.75
1.5
5
t
CP
t
CH
t
CL
t
CSS
t
CSH
t
DS
t
DH
t
CS0
t
CS1
t
CSW
t
BUSY
t
ACC
t
WO
Mil-Std-883 test
method 1008
Mil-Std-883 test
method 1033
T
A
= +85°C
T
A
= +125°C
T
A
= +85°C
T
A
= +125°C
50
10
200,000
50,000
200
80
80
80
0
50
0
20
80
200
12
1
1
µs
BW
THD
f
H_
= 1kHz, L_ = GND, measurement at W_
(Note 6)
Wiper at midscale
C
W_
= 10pF
MAX5488
MAX5489
-90
90
45
0.02
dB
kHz
%
V
IH
V
IL
I
IN
C
IN
5.0
V
DD
= 2.7V to 3.6V
V
DD
= 2.7V to 5.25V (Note 5)
2.4
0.7 x
V
DD
0.8
±1.0
V
V
µA
pF
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
MAX5487/MAX5488/MAX5489
V
H_
= 1V
RMS
at 1kHz, L_ = GND,
measurement at W_
TIMING CHARACTERISTICS (Digital, Figure 2, Note 8)
SCLK Frequency
SCLK Clock Period
SCLK Pulse-Width High
SCLK Pulse-Width Low
CS
Fall to SCLK Rise Setup
SCLK Rise to
CS
Rise Hold
DIN to SCLK Setup
DIN Hold after SCLK
SCLK Rise to
CS
Fall Delay
CS
Rise to SCLK Rise Hold
CS
Pulse-Width High
Write NV Register Busy Time
Read NV Register Access Time
Write Wiper Register to Output Delay
NONVOLATILE MEMORY RELIABILITY
Data Retention
Endurance
Years
Stores
MHz
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ms
µs
µs
_______________________________________________________________________________________
3
Dual, 256-Tap, Nonvolatile, SPI-Interface,
Linear-Taper Digital Potentiometers
MAX5487/MAX5488/MAX5489
DC ELECTRICAL CHARACTERISTICS (continued)
(V
DD
= +2.7V to +5.25V, V
H
= V
DD
, V
L
= GND, T
A
= -40°C to +85°C, unless otherwise noted. Typical values are at V
DD
= +5.0V,
T
A
= +25°C, unless otherwise noted.) (Note 1)
PARAMETER
POWER SUPPLIES
Power-Supply Voltage
Supply Current
Standby Current
V
DD
I
DD
During write cycle only, digital inputs =
V
DD
or GND
Digital inputs = V
DD
or GND, T
A
= +25°C
0.5
2.70
5.25
400
1
V
µA
µA
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Note 1:
All devices are production tested at T
A
= +25°C and are guaranteed by design and characterization for -40°C < T
A
< +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
- V
H
) / I
W
.
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.
VOLTAGE-DIVIDER
CONFIGURATION
H
VARIABLE-RESISTOR
CONFIGURATION
H
W
L
L
Figure 1. Voltage-Divider/Variable-Resistor Configurations
4
_______________________________________________________________________________________
Dual, 256-Tap, Nonvolatile, SPI-Interface,
Linear-Taper Digital Potentiometers
Typical Operating Characteristics
(V
DD
= +5.0V, T
A
= +25°C, unless otherwise noted.)
SUPPLY CURRENT
vs. DIGITAL INPUT VOLTAGE
MAX5487-89 toc01
MAX5487-89 toc02
MAX5487/MAX5488/MAX5489
SUPPLY CURRENT vs. TEMPERATURE
1.2
1.0
SUPPLY CURRENT (µA)
0.8
0.6
0.4
0.2
V
CC
= 3V
0
-40
-15
10
35
60
85
TEMPERATURE (°C)
0
0
V
CC
= 5V
10,000
WIPER RESISTANCE
vs. TAP POSITION (MAX5488)
MAX5487-89toc03
400
SUPPLY CURRENT (µA)
V
CC
= 5V
100
WIPER RESISTANCE (Ω)
1000
300
200
10
V
CC
= 3V
1
100
0
1
2
3
4
5
0
32
64
96
128 160 192 224 256
DIGITAL INPUT VOLTAGE (V)
TAP POSITION
TAP-TO-TAP SWITCHING TRANSIENT
(MAX5488)
MAX5487-89 toc04
TAP-TO-TAP SWITCHING TRANSIENT
(MAX5489)
MAX5487-89 toc05
WIPER TRANSIENT AT POWER-ON
MAX5487-89 toc06
V
H_
= 5.0V
V
H_
= 5.0V
V
H_
= V
DD
CS
2.0V/div
CS
2.0V/div
V
DD
2.0V/div
WIPER
20mV/div
WIPER
20mV/div
WIPER
2.0V/div
1.0µs/div
1.0µs/div
2.0µs/div
_______________________________________________________________________________________
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