MAX5460, MAX5461, MAX5462, MAX5463, MAX5464, MAX5465, MAX5466, MAX5467, MAX5468

MAX5460, MAX5461, MAX5462, MAX5463, MAX5464, MAX5465, MAX5466, MAX5467, MAX5468

19-1956; Rev 3; 11/05

32-Tap FleaPoT

, 2-Wire Digital

Potentiometers

General Description

The MAX5460–MAX5468 linear-taper digital potentiometers perform the same function as a mechanical potentiometer or a variable resistor. These devices consist of a fixed resistor and a wiper contact with 32-tap points that are digitally controlled through a 2-wire serial interface.

The MAX5462/MAX5465/MAX5468 are configured as potentiometers. The rest of the devices in this family are configured as variable resistors. See Pin Configurations for part functionality.

Three resistance values are available: 10kΩ (MAX5466/

MAX5467/MAX5468), 50kΩ (MAX5463/MAX5464/

MAX5465), and 100kΩ (MAX5460/MAX5461/MAX5462).

The MAX5460–MAX5465 (100kΩ and 50kΩ) are available in space-saving 5-pin and 6-pin SC70 packages.

The MAX5466/MAX5467/MAX5468 (10kΩ) are available in 5-pin and 6-pin SOT23 packages.

Applications

LCD Screen Adjustment

Volume Control

Mechanical Potentiometer Replacement

Gain Adjustment

Line Impedance Matching

FleaPoT is a trademark of Maxim Integrated Products Inc.

Functional Diagram appears at end of data sheet.

Features

Miniature SC70 and SOT23 Packages

0.3µA Ultra-Low Supply Current

+2.7V to +5.5V Single-Supply Operation

Glitchless Switching Between Resistor Taps

Power-On Reset to Midscale

2-Wire Up/Down Serial Interface

10k, 50k, and 100kResistance Values

Ordering Information

PART

PIN-

PACKAGE

TOP

MARK

R

(k

)

PKG

CODE

MAX5460EXK 5 SC70

MAX5461EXT 6 SC70

MAX5462EXT 6 SC70

MAX5463EXK 5 SC70

MAX5464EXT

MAX5465EXT

6 SC70

6 SC70

MAX5466EUK 5 SOT23

MAX5467EUT 6 SOT23

ACA

AAP

AAQ

ACB

AAR

AAS

ADQQ

AARH

100

100

100

50

50

50

10

10

X5-1

X6S-1

X6S-1

X5-1

X6S-1

X6S-1

U5-1

U6-1

MAX5468EUT 6 SOT23 AARI 10 U6-1

Note: All devices operate over the -40°C to +85°C temperature range.

Pin Configurations

TOP VIEW

V

DD

1 5 H

GND 2

U/D 3

MAX5460

MAX5463

MAX5466

SOT23, SC70

4 CS

V

DD

1 6 H

GND 2 5 L

U/D 3

MAX5461

MAX5464

MAX5467

SOT23, SC70

4 CS

V

DD

1 6 H

GND 2 5 W

U/D 3

MAX5462

MAX5465

MAX5468

SOT23, SC70

4 CS

________________________________________________________________ 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.

32-Tap FleaPoT

, 2-Wire Digital

Potentiometers

ABSOLUTE MAXIMUM RATINGS

V

DD to GND ..............................................................-0.3V to +6V

All Other Pins to GND.................................-0.3V to (V

DD

+ 0.3)V

Input and Output Latch-Up Immunity.............................±200mA

Maximum Continuous Current into H, L, and W

MAX5460/MAX5461/MAX5462 (100kΩ) .......................±0.6mA

MAX5463/MAX5464/MAX5465 (50kΩ) .........................±1.3mA

MAX5466/MAX5467/MAX5468 (10kΩ) .........................±1.3mA

Continuous Power Dissipation (T

A

= +70°C)

5-pin SC70 (derate 3.1mW/°C above T

A

= +70°C)..........247mW

5-pin SOT23 (derate 7.1mW/°C above T

A

= +70°C)........571mW

6-pin SC70 (derate 3.1mW/°C above T

A

= +70°C) ..........245mW

6-pin SOT23 (derate 8.7mW/°C above T

A

= +70°C).....695.7mW

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

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

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

Soldering 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.

ELECTRICAL CHARACTERISTICS

(V

DD

= +2.7V to +5.5V, V

H

= V

DD

, V

L

= 0, T

A

= -40°C to +85°C. Typical values are at V

DD

= +2.7V, T

A

= +25°C, unless otherwise noted.)

SYMBOL CONDITIONS MIN TYP MAX UNITS PARAMETER

DC PERFORMANCE

Resolution Taps

End-to-End Resistance

End-to-End Resistance Tempco

Ratiometric Resistance Tempco

Integral Nonlinearity

Differential Nonlinearity

Full-Scale Error

Zero-Scale Error

Wiper Resistance

TC

R

INL

DNL

R

W

MAX5460/MAX5461/MAX5462

MAX5463/MAX5464/MAX5465

MAX5466/MAX5467/MAX5468

MAX5462/MAX5465

MAX5468

32

75

37.5

7.5

100

50

10

35

5

±0.5

±0.1

600

160

125

62.5

12.5

±1

±1

1

1200

240 k

Ω ppm/

°C ppm/

°C

LSB

LSB

LSB

LSB

DIGITAL INPUTS

Input High Voltage

Input Low Voltage

V

IH

V

IL

TIMING CHARACTERISTICS (Figures 1, 2)

U/

D Mode to CS Setup t

CU

CS to U/D Step Setup t

CI

CS to U/D Step Hold t

IC

U/

D Step Low Period t

IL

U/

D Step High Period t

IH

Up/Down Toggle Rate (Note 1) f

TOGGLE

Output Settling Time (Note 2) t

SETTLE

100k

Ω var i ab l e r esi stor confi g ur ati on, C

L

= 10p F

100k

Ω p otenti om eter confi g ur ati on, C

L

= 10p F

0.7 x

V

DD

25

50

25

25

25

1

1

0.25

0.3 x

V

DD

V

V ns ns ns ns ns

MHz

µs

2 _______________________________________________________________________________________

32-Tap FleaPoT

, 2-Wire Digital

Potentiometers

ELECTRICAL CHARACTERISTICS (continued)

(V

DD

= +2.7V to +5.5V, V

H

= V

DD

, V

L

= 0, T

A

= -40°C to +85°C. Typical values are at V

DD

= +2.7V, T

A

= +25°C, unless otherwise noted.)

SYMBOL CONDITIONS MIN TYP MAX UNITS PARAMETER

POWER SUPPLIES

Supply Voltage

Active Supply Current (Note 3)

Standby Supply Current (Note 4)

V

DD

I

DD

I

SD

V

DD

= +5V

2.7

0.3

5.5

25

1

V

µA

µA

Note 1: Up/Down Toggle Rate: f

TOGGLE

=

1 t

SETTLE

Note 2: Typical settling times are dependent on end-to-end resistance.

Note 3: Supply current taken while changing wiper tap, f

TOGGLE

= 1MHz.

Note 4: Supply current taken while wiper position is fixed.

Typical Operating Characteristics

(T

A

= +25°C, unless otherwise noted.)

500

400

300

700

WIPER RESISTANCE vs. WIPER VOLTAGE

(MAX5460–MAX5465)

600

V

DD

= +2.7V

V

DD

= +5V

200

100

120

0

0 0.5

1.0

1.5

2.0

2.5

3.0

3.5

WIPER VOLTAGE (V)

4.0

4.5 5.0

W-TO-L RESISTANCE vs. TAP POSITION

100

80

60

40

100kΩ

50kΩ

20

10kΩ

0

1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31

TAP POSITION

200

WIPER RESISTANCE vs. WIPER VOLTAGE

(MAX5466/MAX5467/MAX5468)

180

160

140

120

100

80

60

40

20

0

0

V

DD

= +2.7V

V

DD

= +5V

0.5

1.0 1.5 2.0

2.5 3.0 3.5

WIPER VOLTAGE (V)

4.0

4.5

5.0

0.10

0.05

0

-0.05

-0.10

-0.15

-0.20

END-TO-END RESISTANCE % CHANGE

10kΩ

vs. TEMPERATURE

50kΩ, 100kΩ

SUPPLY CURRENT vs. TEMPERATURE

0.50

0.45

0.40

0.35

0.30

0.25

0.20

0.15

0.10

0.05

0.00

-40 -15

V

DD

= +5V

V

DD

= +2.7V

10 35

TEMPERATURE (°C)

60 85

U/D

2V/div

OUTPUT

W

100mV/div

-0.25

-40 -15 10 35

TEMPERATURE (°C)

60

TAP-TO-TAP SWITCHING TRANSIENT

(MAX5460)

85

200ns/div

_______________________________________________________________________________________

3

32-Tap FleaPoT

, 2-Wire Digital

Potentiometers

Typical Operating Characteristics (continued)

0.15

0.10

0.05

0

-0.05

-0.10

0

(T

A

= +25°C, unless otherwise noted.)

R-DNL ERROR vs. INPUT CODE (100kΩ)

0.08

0.06

0.04

0.02

0

-0.02

-0.04

-0.06

-0.08

-0.10

0 5 10 15 20

INPUT CODE (DECIMAL)

25 30

0.20

R-INL ERROR vs. INPUT CODE (50kΩ)

5 10 15 20

INPUT CODE (DECIMAL)

25 30

0.10

0.08

0.06

0.04

0.02

0

-0.02

-0.04

-0.06

-0.08

-0.10

0

R-INL ERROR vs. INPUT CODE (100kΩ)

5 10 15 20

INPUT CODE (DECIMAL)

25 30

0.15

0.10

0.05

0

-0.05

R-DNL ERROR vs. INPUT CODE (10k)

-0.10

-0.15

-0.20

-0.25

0 5 10 15 20

INPUT CODE (DECIMAL)

25 30

0.04

0.02

0

-0.02

-0.04

-0.06

-0.08

-0.10

-0.12

-0.14

0

R-DNL ERROR vs. INPUT CODE (50kΩ)

5 10 15 20

INPUT CODE (DECIMAL)

25 30

0.30

0.25

0.20

0.15

0.10

0.05

0

-0.05

-0.10

-0.15

0

R-INL ERROR vs. INPUT CODE (10kΩ)

5 10 15 20

INPUT CODE (DECIMAL)

25 30

Pin Description

MAX5460

MAX5463

MAX5466

1

2

3

4

5

PIN

MAX5461

MAX5464

MAX5467

1

2

3

4

6

5

MAX5462

MAX5465

MAX5468

1

2

3

4

6

5

NAME

V

DD

GND

U/

H

L

W

D

CS

FUNCTION

Power Supply

Ground

Up/

Down Control Input. With CS low, a low-to-high transition increments or decrements the wiper position.

Chip Select Input. A high-to-low

CS transition determines the mode: increment if U/

D is high, or decrement if U/

D is low.

High Terminal of Resistor

Low Terminal of Resistor

Wiper Terminal of Resistor

4 _______________________________________________________________________________________

32-Tap FleaPoT

, 2-Wire Digital

Potentiometers

Detailed Description

The MAX5460–MAX5468 consist of a fixed resistor and a wiper contact with 32-tap points that are digitally controlled through a 2-wire serial interface. Three resistance values are available: 10kΩ (MAX5466/MAX5467/

MAX5468), 50kΩ (MAX5463/MAX5464/MAX5465), and

100kΩ (MAX5460/MAX5461/MAX5462).

The MAX5462/MAX5465/MAX5468 are designed to operate as potentiometers. In this configuration, the low terminal of the resistor array is connected to ground (pin 2).

The MAX5461/MAX5464/MAX5467 perform as variable resistors. In these devices, the wiper terminal and high terminal of the resistor array are connected at pin 5.

The MAX5460/MAX5463/MAX5466 are similar variable resistors, except the low terminal is connected to ground (pin 2).

Digital Interface Operation

The MAX5460–MAX5468 have two modes of operation when the serial interface is active: increment and decrement mode. The serial interface is only active when

CS is low.

The

CS and U/D inputs control the position of the wiper along the resistor array. When

CS transitions from high to low, the part will go into increment mode if U/

D is high, and into decrement mode if U/

D is low. Once the mode is set, the device will remain in that mode until

CS goes high again. A low-to-high transition at the U/

D pin will increment or decrement the wiper position depending on the current mode (Figures 1 and 2).

When the

CS input transitions to high (serial interface inactive), the value of the counter is stored and the wiper position is maintained.

Note that when the wiper reaches the maximum (or minimum) tap position, the wiper will not wrap around to the minimum (or maximum) position.

CS t

CU t

IL

U/D t

CI

W

NOTE: "W" IS NOT A DIGITAL SIGNAL. IT REPRESENTS WIPER TRANSITIONS.

Figure 1. Serial Interface Timing Diagram, Increment Mode

CS t

SETTLE t

CU t

IH

U/D t

IH t

IC t

SETTLE t

IC t

IL t

CI

W t

SETTLE t

SETTLE

NOTE: "W" IS NOT A DIGITAL SIGNAL. IT REPRESENTS WIPER TRANSITIONS.

Figure 2. Serial Interface Timing Diagram, Decrement Mode

_______________________________________________________________________________________ 5

32-Tap FleaPoT

, 2-Wire Digital

Potentiometers

Power-On Reset

All parts in this family feature power-on reset (POR) circuitry that sets the wiper position to midscale at powerup. By default, the chip is in the increment mode.

Applications Information

The MAX5460–MAX5468 are intended for circuits requiring digitally controlled adjustable resistance, such as LCD contrast control, where voltage biasing adjusts the display contrast.

Controlling a Switch-Mode

LCD Bias Generator

Figure 3 shows an application where the variable resistor 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

MAX5461/MAX5464/MAX5467. Similarly, Figure 4 shows the application of the variable resistor in a digitally controlled negative LCD-bias circuit along with the

MAX774/MAX775/MAX776.

Alternative Positive

LCD Bias Control

Alternatively, use an op amp to provide buffering and gain to the output of the MAX5462/MAX5465/MAX5468.

Connect the mechanical potentiometer to the positive input of a noninverting op amp (Figure 5) to select a portion of the input signal by digitally controlling the wiper terminal. Figure 6 shows a similar circuit for the

MAX5461/MAX5464/MAX5467.

Adjustable Gain

Figure 7 shows how to use the variable resistor to digitally adjust the gain of a noninverting op amp configuration. Connect the MAX5461/MAX5464/MAX5467 in series with a resistor to ground to form the adjustable gain control of a noninverting amplifier. The MAX5460–

MAX5468 have a low 5ppm/°C ratiometric tempco that allows for a very stable adjustable gain configuration over temperature.

V

IN

= 5V

C1

68µF

5

REF

C2

0.1µF

V+

2

C3

0.1µF

4

SHDN

MAX1771

6

AGND

EXT

1

L1

22µH

D1

1N5817-22

C4

300µF

N

MTD20N03HDL

CS

8

R

SENSE

40mΩ

FB

3

R2

V

OUT

= 12V

AT 0.5A

GND

7

R

VAR

C5

MAX5461

MAX5464

MAX5467

R1

V

REF

= 1.5V

V

OUT(MAX)

V

REF

=

R2

+ 1

R1

V

OUT(MIN)

=

V

REF

( R2

VAR(MAX)

)

+ 1

Figure 3. Adjustable Positive LCD Bias

V

IN

C1

150µF

C2

0.1µF

1

OUT V+

5

R2

3

SHDN

2

FB

CS

6

EXT

7

R3

0.07Ω

Q1

Si9435

P

MAX5461

MAX5464

MAX5467

MAX774

MAX775

MAX776

R

VAR

R1 4

C3

0.1µF

REF

GND

8

L1

22µH

1N5822/

MBR340

C4

*

*

MAX774 = 330µF, 10V

MAX775/MAX776 = 120µF, 20V

V

OUT(MAX)

V

REF

=

R2

,

V

OUT(MIN)

R1 V

=

R2

REF

R1 + R

VAR

V

REF

- V

FB

R1 + R

VAR

≥ 5µA (FOR 2% GAIN-SETTING ACCURACY)

V

OUT

Figure 4. Adjustable Negative LCD Bias

6 _______________________________________________________________________________________

+5V

H

W

L

MAX5462

MAX5465

MAX5468

Figure 5. Positive LCD Bias Control

V

CC

V

IN

V

OUT

30V

32-Tap FleaPoT

, 2-Wire Digital

Potentiometers

+5V

H

30V

V

OUT

V

OUT

MAX5461

MAX5464

MAX5467

L

Figure 6. Positive LCD Bias Control

V

CC

V

IN

V

OUT

H

L

MAX5461

MAX5464

MAX5467

a)

Figure 7. Adjustable Gain Circuit

b)

L

W

MAX5462

MAX5465

MAX5468

H

_______________________________________________________________________________________ 7

32-Tap FleaPoT

, 2-Wire Digital

Potentiometers

Functional Diagram

H

V

DD

GND

MAX5460–MAX5468

CS

U/D

UP/DN

COUNTER

32-POSITION

DECODER

W

L

TRANSISTOR COUNT: 792

Chip Information

8 _______________________________________________________________________________________

32-Tap FleaPoT

, 2-Wire Digital

Potentiometers

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.)

PACKAGE OUTLINE, 5L SC70

21-0076 C

1

1

PACKAGE OUTLINE, SOT-23, 5L

21-0057 E

1

1

_______________________________________________________________________________________ 9

32-Tap FleaPoT

, 2-Wire 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.)

PACKAGE OUTLINE, SOT 6L BODY

21-0058 G

1

1

PACKAGE OUTLINE, 6L SC70

21-0077 C

1

1

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.

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

© 2005 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products, Inc.

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