MAX5460_技术文档

19-1956; Rev 2; 9/02

32-Tap FleaPoT^™, 2-Wire Digital

Potentiometers

General Description

Features

The MAX5460–MAX5468 linear-taper digital potentiome-

ters perform the same function as a mechanical poten-

tiometer 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.

ꢀ 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

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.

ꢀ 2-Wire Up/Down Serial Interface

ꢀ 10kΩ, 50kΩ, and 100kΩ Resistance Values

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 avail-

able 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

Ordering Information

TOP

MARK

LCD Screen Adjustment

Volume Control

TEMP

RANGE

PIN-

PACKAGE

PART

R (kΩ)

MAX5460EXK -40°C to +85°C 5 SC70

MAX5461EXT -40°C to +85°C 6 SC70

MAX5462EXT -40°C to +85°C 6 SC70

MAX5463EXK -40°C to +85°C 5 SC70

MAX5464EXT -40°C to +85°C 6 SC70

MAX5465EXT -40°C to +85°C 6 SC70

ACA

AAP

100

50

Mechanical Potentiometer Replacement

Gain Adjustment

AAQ

ACB

Line Impedance Matching

AAR

50

AAS

50

MAX5466EUK

-40°C to +85°C 5 SOT23

ADQQ

AARH

AARI

10

FleaPoT is a trademark of Maxim Integrated Products Inc.

MAX5467EUT -40°C to +85°C 6 SOT23

MAX5468EUT -40°C to +85°C 6 SOT23

10

Functional Diagram appears at end of data sheet.

10

Pin Configurations

TOP VIEW

V

1

2

3

5

4

H

V

1

2

3

6

5

4

H

V

DD

1

2

3

6

5

4

H

DD

GND

U/D

GND

U/D

GND

U/D

L

W

CS

MAX5460

MAX5463

MAX5466

MAX5461

MAX5464

MAX5467

MAX5462

MAX5465

MAX5468

CS

SOT23, SC70

________________________________________________________________ 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

Continuous Power Dissipation (T = +70°C)

A

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

+ 0.3)V

5-pin SC70 (derate 3.1mW/°C above T = +70°C)..........247mW

DD

A

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

Maximum Continuous Current into H, L, and W

5-pin SOT23 (derate 7.1mW/°C above T = +70°C)........571mW

A

6-pin SC70 (derate 3.1mW/°C above T = +70°C)..........245mW

A

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

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

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

6-pin SOT23 (derate 8.7mW/°C above T = +70°C).....695.7mW

A

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

= +2.7V to +5.5V, V = V , V = 0, T = -40°C to +85°C. Typical values are at V

= +2.7V, T = +25°C, unless

DD A

DD

H

DD

L

A

otherwise noted.)

PARAMETER

SYMBOL

CONDITIONS

MIN

TYP

MAX

UNITS

Taps

kΩ

DC PERFORMANCE

Resolution

32

75

MAX5460/MAX5461/MAX5462

MAX5463/MAX5464/MAX5465

MAX5466/MAX5467/MAX5468

100

50

10

35

5

125

62.5

12.5

End-to-End Resistance

37.5

7.5

End-to-End Resistance Tempco

Ratiometric Resistance Tempco

Integral Nonlinearity

TC

ppm/°C

LSB

R

INL

0.5

1

Differential Nonlinearity

Full-Scale Error

DNL

LSB

0.1

LSB

Zero-Scale Error

1

LSB

MAX5460–MAX5465

600

160

1200

240

Wiper Resistance

R

W

Ω

MAX5466/MAX5467/MAX5468

DIGITAL INPUTS

Input High Voltage

Input Low Voltage

V

0.7 x V

DD

V

IH

V

0.3 x V

DD

IL

TIMING CHARACTERISTICS (Figures 1, 2)

U/D Mode to CS Setup

CS to U/D Step Setup

CS to U/D Step Hold

t

25

50

25

ns

CU

t

CI

IC

t

ns

U/D Step Low Period

t

ns

IL

U/D Step High Period

Up/Down Toggle Rate (Note 1)

t

ns

IH

f

1

MHz

TOGGLE

100kΩ variable resistor configuration, C = 10pF

L

Output Settling Time (Note 2)

t

µs

SETTLE

100kΩ potentiometer configuration, C = 10pF

0.25

L

2

_______________________________________________________________________________________

32-Tap FleaPoT^™, 2-Wire Digital

Potentiometers

ELECTRICAL CHARACTERISTICS (continued)

(V

= +2.7V to +5.5V, V = V , V = 0, T = -40°C to +85°C. Typical values are at V

= +2.7V, T = +25°C, unless

DD A

DD

H

DD

L

A

otherwise noted.)

PARAMETER

SYMBOL

CONDITIONS

MIN

TYP

MAX

UNITS

POWER SUPPLIES

Supply Voltage

V

2.7

5.5

25

1

V

DD

Active Supply Current (Note 3)

Standby Supply Current (Note 4)

I

µA

DD

I

V

= +5V

DD

0.3

SD

Note 1: Up/Down Toggle Rate:

1

f

=

TOGGLE

t

SETTLE

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

Note 3: Supply current taken while changing wiper tap, f = 1MHz.

TOGGLE

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

Typical Operating Characteristics

(T = +25°C, unless otherwise noted.)

A

WIPER RESISTANCE vs. WIPER VOLTAGE

(MAX5466/MAX5467/MAX5468)

END-TO-END RESISTANCE % CHANGE

vs. TEMPERATURE

WIPER RESISTANCE vs. WIPER VOLTAGE

(MAX5460–MAX5465)

200

180

160

140

120

100

80

0.10

0.05

0

700

600

500

400

300

200

100

0

V

= +2.7V

DD

V

= +2.7V

DD

10kΩ

-0.05

-0.10

-0.15

-0.20

-0.25

V

= +5V

DD

V

= +5V

DD

50kΩ, 100kΩ

60

40

20

0

0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0

WIPER VOLTAGE (V)

-40

-15

10

35

60

85

0

0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0

WIPER VOLTAGE (V)

TEMPERATURE (°C)

TAP-TO-TAP SWITCHING TRANSIENT

(MAX5460)

W-TO-L RESISTANCE

vs. TAP POSITION

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

120

100

80

60

40

20

0

U/D

100kΩ

2V/div

V

= +5V

DD

50kΩ

10kΩ

V

= +2.7V

35

OUTPUT

W

100mV/div

DD

200ns/div

1

3

5

7

9 11 13 15 17 19 21 23 25 27 29 31

TAP POSITION

-40

-15

10

60

85

TEMPERATURE (°C)

_______________________________________________________________________________________

3

32-Tap FleaPoT^™, 2-Wire Digital

Potentiometers

Typical Operating Characteristics (continued)

(T = +25°C, unless otherwise noted.)

A

R-DNL ERROR vs. INPUT CODE (100kΩ)

R-INL ERROR vs. INPUT CODE (100kΩ)

R-DNL ERROR vs. INPUT CODE (50kΩ)

0.08

0.04

0.02

0

0.10

0.08

0.06

0.04

0.02

0

0.06

0.04

0.02

0

-0.02

-0.04

-0.06

-0.08

-0.10

-0.12

-0.14

-0.02

-0.04

-0.06

-0.08

-0.10

-0.02

-0.04

-0.06

-0.08

-0.10

0

5

10

15

20

25

30

0

5

10

15

20

25

30

0

5

10

15

20

25

30

INPUT CODE (DECIMAL)

R-INL ERROR vs. INPUT CODE (10kΩ)

R-DNL ERROR vs. INPUT CODE (10kΩ)

R-INL ERROR vs. INPUT CODE (50kΩ)

0.15

0.10

0.05

0

0.30

0.25

0.20

0.15

0.10

0.05

0

0.20

0.15

0.10

0.05

0

-0.05

-0.10

-0.15

-0.05

-0.10

-0.15

-0.05

-0.10

-0.20

-0.25

0

5

10

15

20

25

30

0

5

10

15

25

30

20

0

5

10

15

20

25

30

INPUT CODE (DECIMAL)

Pin Description

MAX5460

MAX5463

MAX5466

MAX5461

MAX5464

MAX5467

MAX5462

MAX5465

MAX5468

NAME

FUNCTION

1

2

1

2

1

2

V

Power Supply

Ground

DD

GND

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

transition increments or decrements the wiper position.

3

U/D

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.

4

CS

5

6

5

6

—

5

H

L

High Terminal of Resistor

Low Terminal of Resistor

Wiper Terminal of Resistor

—

W

4

_______________________________________________________________________________________

32-Tap FleaPoT^™, 2-Wire Digital

Potentiometers

Digital Interface Operation

Detailed Description

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 MAX5460–MAX5468 consist of a fixed resistor and a

wiper contact with 32-tap points that are digitally con-

trolled 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 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 incre-

ment or decrement the wiper position depending on the

current mode (Figures 1 and 2).

The MAX5462/MAX5465/MAX5468 are designed to oper-

ate as potentiometers. In this configuration, the low termi-

nal 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).

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 mini-

mum) tap position, the wiper will not wrap around to the

minimum (or maximum) position.

CS

t

CU

t

IC

t

IL

U/D

W

t

IH

CI

t

SETTLE

t

SETTLE

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

Figure 1. Serial Interface Timing Diagram, Increment Mode

CS

t

IC

t

CU

t

IH

U/D

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

Alternative Positive

LCD Bias Control

All parts in this family feature power-on reset (POR) cir-

cuitry that sets the wiper position to midscale at power-

up. By default, the chip is in the increment mode.

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.

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.

Adjustable Gain

Figure 7 shows how to use the variable resistor to digi-

tally adjust the gain of a noninverting op amp configura-

tion. 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.

Controlling a Switch-Mode

LCD Bias Generator

Figure 3 shows an application where the variable resis-

tor is used with a MAX1771 to make an adjustable posi-

tive 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 digi-

tally controlled negative LCD-bias circuit along with the

MAX774/MAX775/MAX776.

V

= 5V

IN

V

IN

C1

C2

C1

150µF

C2

68µF

0.1µF

5

1

3

2

0.1µF

OUT

V+

2

L1

R3

0.07Ω

V+

22µH

R2

V

= 12V

AT 0.5A

D1

OUT

5

4

6

SHDN

REF

1N5817-22

6

7

CS

C3

0.1µF

Q1

Si9435

C4

300µF

MAX1771

1

8

FB

EXT

SHDN

AGND

EXT

CS

FB

P

N

V

OUT

MTD20N03HDL

MAX5461

MAX5464

MAX5467

MAX774

MAX775

MAX776

R

SENSE

40mΩ

R2

C5

3

R

VAR

GND

7

1N5822/

MBR340

R

R1

4

VAR

L1

22µH

MAX5461

MAX5464

MAX5467

REF

C4*

GND

8

C3

0.1µF

R1

* MAX774 = 330µF, 10V

MAX775/MAX776 = 120µF, 20V

V

= 1.5V

REF

V

R2

R1

OUT(MAX)

V

R2

R1

V

R2

OUT(MAX)

OUT(MIN)

=

+ 1

=

,

=

V

REF

V

R1 + R

VAR

REF

- V

R2

REF

FB

OUT(MIN)

≥ 5µA (FOR 2% GAIN-SETTING ACCURACY)

+ 1

(

)

R1 + R

VAR

V

R1 + R

VAR(MAX)

REF

Figure 4. Adjustable Negative LCD Bias

Figure 3. Adjustable Positive LCD Bias

6

_______________________________________________________________________________________

32-Tap FleaPoT^™, 2-Wire Digital

Potentiometers

+5V

H

30V

W

V

OUT

V

OUT

L

MAX5461

MAX5464

MAX5467

MAX5462

MAX5465

MAX5468

Figure 6. Positive LCD Bias Control

Figure 5. Positive LCD Bias Control

V

CC

V

CC

V

IN

V

IN

V

OUT

V

OUT

H

W

L

H

MAX5461

MAX5464

MAX5467

L

MAX5462

MAX5465

MAX5468

a)

b)

Figure 7. Adjustable Gain Circuit

_______________________________________________________________________________________

7

32-Tap FleaPoT^™, 2-Wire Digital

Potentiometers

Functional Diagram

H

V

DD

MAX5460–MAX5468

GND

CS

UP/DN

COUNTER

32-POSITION

DECODER

W

U/D

L

Chip Information

TRANSISTOR COUNT: 792

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.)

_______________________________________________________________________________________

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.)

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

Printed USA

is a registered trademark of Maxim Integrated Products.


型号：	MAX5460
厂家：	MAXIM INTEGRATED PRODUCTS
描述：	32-Tap FleaPoT⑩, 2-Wire Digital Potentiometers 32抽头FleaPoT ™ ， 2线数字电位器电位器
文件：	总10页 (文件大小：265K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

MAX5460 [MAXIM]

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MAX5461EXT-T

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MAX5462EXT+

MAX5462EXT-T