Datasheet MAX5161MEUT, MAX5161LEUT, MAX5160NEUA, MAX5160MEUA, MAX5160LEUA Datasheet (Maxim)

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General Description

The MAX5160/MAX5161 linear-taper digital potentiome­ters perform the same function as a mechanical poten­tiometer or a variable resistor. They consist of a fixed
resistor and a wiper contact with 32 tap points that are
digitally controlled by three lines for the 8-pin MAX5160
or by two lines for the 6-pin MAX5161.

These parts are ideal for applications requiring digitally
controlled resistors. Three resistance values are avail­able for each part type: 50kΩ, 100kΩ, and 200kΩ. A
nominal resistor temperature coefficient of 50ppm/°C
end-to-end and only 5ppm/°C ratiometric makes the
MAX5160 ideal for applications requiring a low-temper­ature-coefficient variable resistor, such as low-tempco,
adjustable-gain circuit configurations.

The MAX5160 is available in an 8-pin µMAX package,
and the MAX5161 is available in a 6-pin SOT23 pack­age. Both devices are guaranteed over the extended­industrial temperature range (-40°C to +85°C).

Applications

LCD Screen Adjustment
Volume Control
Mechanical Potentiometer Replacement

Features

♦ 32 Tap Positions
♦ 50kΩ, 100kΩ, and 200kΩ Resistance Values
♦ 400Ω Wiper Resistance
♦ ±25% Resistance Tolerance
♦ 3-Wire Serial Data Input
♦ ±1LSB DNL
♦ ±0.5LSB INL
♦ 100nA Supply Current
♦ Single-Supply Operation: +2.7V to +5.5V
♦ Power-On Reset: Wiper Goes to Midscale

(position 16)

♦ ±2kV ESD Protection
♦ Small-Footprint Packages

6-Pin SOT23 (MAX5161)
8-Pin µMAX (MAX5160)

♦ Glitchless Switching Between the Resistor Taps

MAX5160/MAX5161

Low-Power Digital Potentiometers

________________________________________________________________

Maxim Integrated Products

1

1
2
3
4

8
7
6
5

V

DD

CS
L
WGND

H

U/D

INC

MAX5160

µMAX

TOP VIEW

H

U/DGND

16V

DD

5 INC

L

MAX5161

SOT23-6

2

34

Functional Diagram

19-1435; Rev 1; 4/99

PART

MAX5160NEUA

MAX5160MEUA

PIN­PACKAGE

8 µMAX
8 µMAX

Pin Configurations

Ordering Information

-40°C to +85°C

-40°C to +85°C

TEMP. RANGE

MAX5160LEUA -40°C to +85°C 8 µMAX
MAX5161NEUT

-40°C to +85°C 6 SOT23-6
MAX5161MEUT -40°C to +85°C 6 SOT23-6
MAX5161LEUT -40°C to +85°C 6 SOT23-6

R

(kΩ)

200
100

50
200
100

50

H

V

DD

GND

CS
INC
U/D

MAX5160
MAX5161

UP/DN

COUNTER

POSITION
DECODER

L

W

MAX5160/MAX5161

Low-Power Digital Potentiometers

2 _______________________________________________________________________________________

Note 1: For the MAX5160, linearity is defined in terms of H to L code-dependent resistance.

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

(VDD= +2.7V to +5.5V, VH= VDD, VL= 0, TA = T

MIN

to T

MAX

. Typical values are at VDD= 5V, TA= +25°C, unless otherwise noted.)

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 +6V

CS, INC, U/D to GND ...............................................-0.3V to +6V

H, L, W to GND.......................................... -0.3V to (V

DD

+ 0.3V)

Input and Output Latchup Immunity ..............................±200mA

Maximum Continuous Current into H, L, and W

MAX516_ _ E _ _..............................................................±1mA

Continuous Power Dissipation (T

A

= +70°C)

6-Pin SOT23 (derate 8.7mW/°C above +70°C).............696mW

8-Pin µMAX (derate 4.1mW/°C above +70°C)..............330mW

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

Storage Temperature Range.............................-65°C to +150°C

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

MAX516_ME_ _

MAX516_NE_ _

MAX516_LE_ _

CONDITIONS

ns50t

DI

U/D to INC Setup

ns0t

ID

U/D to INC Hold

ns25t

IH

INC High Period

ns25t

IL

INC Low Period

ns0t

IC

CS to INC Hold Time

ns25t

CI

CS to INC Setup Time

pF5Input Capacitance

µA±1Input Leakage Current

V

0.3 · V

DD

V

IL

Input Low Voltage

V

0.7 · V

DD

V

IH

Input High Voltage

kΩ

37.5 50 62.5

HLEnd-to-End Resistance

LSB±1/2INLIntegral Nonlinearity (Note 1)

%3Resolution

75 100 125

150 200 250

Ω400 1700R

W

Wiper Resistance

LSB+0.1Zero-Scale Error

LSB±1DNLDifferential Nonlinearity (Note 1)

ppm/°C50TC

R

End-to-End Resistor Tempco

ppm/°C5Ratiometric Resistor Tempco

LSB-0.1Full-Scale Error

UNITSMIN TYP MAXSYMBOLPARAMETER

MHz7f

IMAX

INC Frequency

µs1t

IW

Wiper-Settling Time

CS = INC = U/D =
V

DD

or GND

nA135

I

DD

Supply Current

µA0.6 10

V2.7 5.5V

DD

Supply Voltage

VDD= 5V
VDD= 2.7V

pF10C

W

Wiper Capacitance

DIGITAL INPUTS

TIMING CHARACTERISTICS (Figure 6)

POWER SUPPLIES

DC PERFORMANCE

MAX5160/MAX5161

Low-Power Digital Potentiometers

_______________________________________________________________________________________

3

0

200

400

600

800

1,000

012345

WIPER RESISTANCE
vs. WIPER VOLTAGE

MAX5160/61 toc01

WIPER VOLTAGE (V)

WIPER RESISTANCE (Ω)

R

WMAX

= 574.0804

VDD = +2.7V

VDD = +5V

-0.16

-0.1

-0.12

-0.14

0

-0.02

-0.04

-0.06

-0.08

0.02

0.04

0.06

-40-30-20-100102030405060708090

END-TO-END RESISTANCE % CHANGE

vs. TEMPERATURE

MAX5160/61 toc02

TEMPERATURE (°C)

END-TO-END RESISTANCE % CHANGE

200kΩ

200kΩ

100kΩ

50kΩ

50kΩ

100kΩ

0

50
25

125
100

75

150

175

200

225

1 5 9 131721252933

END-TO-END RESISTANCE

vs. TAP POSITION

MAX5160/61 toc03

TAP POSITION

RESISTANCE (kΩ)

200kΩ

0

20
10

50
40
30

60

70

80

90

100

110

1 5 9 131721252933

END-TO-END RESISTANCE

vs. TAP POSITION

MAX5160/61 toc04

TAP POSITION

RESISTANCE (kΩ)

100kΩ

Typical Operating Characteristics

(VDD= +5V, TA= +25°C, unless otherwise noted.)

0

10

5

25
20
15

30

35

40

45

50

1 5 9 131721252933

END-TO-END RESISTANCE

vs. TAP POSITION

MAX5160/61 toc05

TAP POSITION

RESISTANCE (kΩ)

50kΩ

MAX5160/MAX5161

Low-Power Digital Potentiometers

4 _______________________________________________________________________________________

PIN

Typical Operating Characteristics (continued)

(VDD= +5V, TA= +25°C, unless otherwise noted.)

0

0.2

0.1

0.5

0.4

0.3

0.8

0.7

0.6

0.9

-40 0 20-20 40 60 80 100

SUPPLY CURRENT vs. TEMPERATURE

MAX5160/61 toc06

TEMPERATURE (°C)

SUPPLY CURRENT (µA)

VDD = +5V

VDD = +2.7V

1

INC

Wiper Increment Control Input. With CS low, a high-to-low transition increments
(U/D high) or decrements (U/D low) the wiper position.

2

U/D

Up/Down Control Input. With CS low, a high-to-low INC transition increments

(U/D high) or decrements (U/D low) the wiper position.
3 H High Terminal of Resistor
4 GND Ground

8 V

DD

Power Supply

7

CS Chip-Select Input. Drive low to change the wiper position via INC and U/D.

6 L Low Terminal of Resistor

5 W Wiper Terminal of Resistor

Pin Description

NAME FUNCTION

MAX5160

5

4

PIN

2
3

6

—

1

—

MAX5161

2V/div

OUTPUT

50mV/div

INC

TAP-TO-TAP SWITCHING TRANSIENT

W

0V

0V

5µs/div

MAX5160/61 toc07

MAX5160/MAX5161

Low-Power Digital Potentiometers

_______________________________________________________________________________________ 5

Detailed Description

The MAX5160/MAX5161 consist of resistor arrays with
31 resistive elements. Thirty-two tap points are accessi­ble to the wiper along the resistor string between H and
L. Logic inputs CS, U/D, and INC determine the posi­tion of the wiper. With CS low and U/D high, a high-to­low transition on INC increments the internal counter,
increasing the resistance between W and L. When both
CS and U/D are low, a high-to-low INC transition
decrements the internal counter, decreasing the resis­tance between W and L. At either end (maximum or mini­mum positions), additional transitions in the direction of
the end points will not change the counter value (the
counter will not wrap around).

The H and L terminals of the MAX5160 are similar to the
two end terminals of a mechanical potentiometer. The
tap W is equivalent to the variable tap (wiper) of the
potentiometer.

The MAX5161 is similar to the MAX5160 except that CS
internally connects to ground and the wiper terminal (W)
is shorted to the high terminal (H). The MAX5161 acts as

a variable resistor (a potentiometer with the wiper and
one end terminal shorted together).

The MAX5160/MAX5161 feature power-on reset circuit­ry that sets the wiper position to midscale at power-up.

Applications Information

The MAX5160/MAX5161 are intended for circuits
requiring digitally controlled adjustable voltage or
adjustable gain, such as LCD contrast control, where
voltage biasing adjusts the display contrast.

Controlling a Switch-Mode

LCD Bias Generator

Figure 1 shows an application where the MAX5161 is
used with a MAX1771 to make an adjustable positive
LCD-bias circuit. The output of the MAX1771 is a posi­tive voltage that is digitally controlled through the
MAX5160/MAX5161. Similarly, Figure 2 shows the
application of the MAX5161 in a digitally controlled
negative LCD-bias circuit along with the MAX774/
MAX775/MAX776.

MAX1771

VIN = 5V

REF

SHDN

AGND

GND

N

MTD20N03HDL

7

EXT

CS

FB

L1

22µH

D1

1N5817-22

C4

300µF

C5

C3

0.1µF

5

4

6

1

8

3

2

V+

C1

68µF

V

OUT

= 12V

AT 0.5A

R2

R

SENSE

40mΩ

C2

0.1µF

V

REF

= 1.5V

R1

R

VAR

V

OUT(MAX)

= R2

+ 1

V

REF

R1

V

OUT(MIN)

=

(

R2 )

+ 1

V

REF

R1 + R

VAR(MAX)

MAX5161

Figure 1. Adjustable Positive LCD Bias

MAX774
MAX775
MAX776

OUT V+

SHDN

CS

FB EXT

GND

P

7

8

C2

0.1µF
R3

0.07Ω

R1

R2

R

VAR

C1

150µF

6

5

2

3

1

REF

4

Q1
Si9435

1N5822/
MBR340

L1

22µH

C4*

V

IN

C3

0.1µF

V

OUT

* MAX774 = 330µF, 10V

MAX775, MAX776 = 120µF, 20V

V

OUT(MAX)

= R2

,

V

OUT(MIN)

= R2

V

REF

R1 V

REF

R1 + R

VAR

V

REF

- VFB
5µA (FOR 2% GAIN-SETTING ACCURACY)

R1 + R

VAR

MAX5161

Figure 2. Adjustable Negative LCD Bias

MAX5160/MAX5161

Alternative Positive

LCD Bias Control

Alternatively, use an op amp to provide buffering and
gain to the output of the MAX5160/MAX5161. Connect
the MAX5160 to the positive input of a noninverting op
amp (Figure 3) to select a portion of the input signal by
digitally controlling the wiper terminal. Figure 4 shows a
similar circuit for the MAX5161.

Adjustable Gain

Figure 5 shows how to use the MAX5161 to digitally
adjust the gain of a noninverting op amp configuration.
Connect the MAX5161 in series with a resistor to ground
to form the adjustable gain control of a noninverting
amplifier. The MAX5160/MAX5161 have a low 5ppm/°C
ratiometric tempco that allows for a very stable adjust­able gain configuration over temperature.

Serial Interface

Figure 6 is the serial-interface timing diagram.

Low-Power Digital Potentiometers

6 _______________________________________________________________________________________

GAIN 6

30V

W

L

H

INC

CS

GND

+5V

+5V

V

OUT

V

DD

U/D

MAX5160

Figure 3. MAX5160 Positive LCD Bias Control

GAIN 6

30V

L

H

GND

+5V+5V

V

OUT

V

DD

INC
U/D

MAX5161

Figure 4. MAX5161 Positive LCD Bias Control

V

CC

L

H

GND

V

IN

+5V

a)

b)

V

OUT

V

DD

INC
U/D

V

CC

L

H

W

V

IN

V

OUT

MAX5161

MAX5160

Figure 5. Adjustable Gain Circuit: a) MAX5161; b) MAX5160

Chip Information

TRANSISTOR COUNT: 969

MAX5160/MAX5161

Low-Power Digital Potentiometers

_______________________________________________________________________________________ 7

H +L

↓

H

L —L

↓

OL

↑

L OL

↑

R

W

O

INC

X

U/D

xx-X

CS

H

CS

Figure 6. Serial-Interface Timing Diagram

Truth Table

X =

Don’t care

O =

Previous state

+ =

Increment

— =

Decrement

↓

= High-to-Low Transition

↑ =

Low-to-High Transition

INC

U/D

W

t

CI

t

IL

t

DI

t

ID

t

IW

t

IC

t

IH

MAX5160/MAX5161

Low-Power Digital Potentiometers

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.

8

_____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600

© 1999 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.

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.

8

_____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600

© 1999 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.

Package Information

8LUMAXD.EPS

6LSOT.EPS