MAX5395MATA+ - Maxim Integrated

General Description

The MAX5395 single, 256-tap volatile, low-voltage

linear taper digital potentiometer offers three end-to-

end resistance values of 10kΩ, 50kΩ, and 100kΩ.

Potentiometer terminals are independent of supply for

voltages up to 5.25V with single-supply operation from

1.7V to 5.5V (charge pump enabled). User-controlled

shutdown modes allow the H, W, or L terminal to be

opened with the wiper position set to zero-code, mid-

code, full-code, or the value contained in the wiper

be achieved for supply voltages between 2.6V and 5.5V

by disabling the internal charge pump and not allowing

potentiometer terminals to exceed the supply voltage by

more than 0.3V. The MAX5395 provides a low 50ppm/°C

end-to-end temperature coefficient and features an I2C

serial interface.

The small package size, low operating supply voltage,

low supply current, and automotive temperature range

of the MAX5395 make the device uniquely suited for the

portable consumer market and battery-backup industrial

applications.

The MAX5395 is available in a lead-free, 8-pin TDFN

(2mm x 2mm) package. The device operates over the

-40°C to +125°C automotive temperature range.

Benets and Features

●Single Linear Taper 256-Tap Positions

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

● 1.7V to 5.5V Extended Single Supply

●0 to 5.25V H, W, L Operating Voltage Independent of VDD

● 1μA (typ) Supply Current in Low-Power Mode

● ±1.0 LSB INL, ±0.5 LSB DNL (max) Wiper Accuracy

● Power-On Sets Wiper to Midscale

● 50ppm/°C End-to-End Temperature Coefficient

● 5ppm/°C Ratiometric Temperature Coefficient

● -40°C to +125°C Operating Temperature Range

● 2mm x 2mm, 8-Pin TDFN Package

●I2C-Compatible Serial Interface

Applications

● Portable Electronics

● System Calibration

● Battery-Powered Systems

● Mechanical Potentiometer Replacement

Ordering Information appears at end of data sheet.

19-6393; Rev 3; 2/16

I2C

INTERFACE

1.7V TO 5.5V

(CHARGE PUMP ENABLED) H

LR1

+5V

VDD

MAX5395

MAX4250

GND

VO/VS = 1 + RMAX5395/R1

SDA

SCL

ADDR0

MAX5395 Single, 256-Tap Volatile, I2C, Low-Voltage Linear

Taper Digital Potentiometer

Typical Operating Circuit

(All voltages referenced to GND.)

VDD ........................................................................-0.3V to +6V

H, W, L (charge pump enabled) ..........................-0.3V to +5.5V

H, W, L (charge pump disabled) ..................-0.3V to the lower of

(VDD + 0.3V) or +6V

ADDR0 ..................... -0.3V to the lower of (VDD + 0.3V) or +6V

All Other Pins .........................................................-0.3V to +6V

Continuous Current into H, W, and L

MAX5395L ........................................................................5mA

MAX5395M .......................................................................2mA

MAX5395N .......................................................................1mA

Maximum Current into Any Input ........................................50mA

Continuous Power Dissipation (TA = +70°C)

TDFN (derate 11.9mW/°C above +70°C) .................953.5mW

Operating Temperature Range ........................ -40°C to +125°C

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

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

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

Soldering Temperature (reflow) ......................................+260°C

TDFN

Junction-to-Ambient Thermal Resistance (θJA) .......83.9°C/W Junction-to-Ambient Thermal Resistance (θJC) .......37.0°C/W

(Note 1)

(VDD = 1.7V to 5.5V, VH = V

DD, VL = GND, TA = -40°C to +125°C, unless otherwise noted. Typical values are at VDD = 1.8V,

TA = +25°C.) (Note 2)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

RESOLUTION

256-Tap Family N 256 Tap

DC PERFORMANCE (Voltage-Divider Mode)

Integral Nonlinearity (Note 3) INL -1.0 +1.0 LSB

Differential Nonlinearity DNL (Note 3) -0.5 +0.5 LSB

Ratiometric Resistor Tempco (DVW/VW)/DT, VH = VDD, VL = GND, No

Load 5ppm/°C

Full-Scale Error (Code FFh)

Charge pump enabled, 1.7V < VDD < 5.5V -0.5

LSB

Charge pump disabled,

2.6V < VDD < 5.5V

MAX5395M

MAX5395N -0.5

MAX5395L -1.0

Zero-Scale Error (Code 00h)

Charge pump enabled, 1.7V < VDD < 5.5V +0.5

LSB

Charge pump disabled,

2.6V < VDD < 5.5V

MAX5395M

MAX5395N +0.5

MAX5395L +1.0

DC PERFORMANCE (Variable Resistor Mode)

Integral Nonlinearity (Note 4) R-INL

Charge pump enabled, 1.7V < VDD < 5.5V -1.0 +1.0

LSB

Charge pump disabled,

2.6V < VDD < 5.5V

MAX5395M

MAX5395N -1.0 +1.0

MAX5395L -1.5 +1.5

Differential Nonlinearity R-DNL (Note 4) -0.5 +0.5 LSB

Wiper Resistance (Note 5) RWL

Charge pump enabled, 1.7V < VDD < 5.5V 25 50 Ω

Charge pump disabled, 2.6V < VDD < 5.5V 200

MAX5395 Single, 256-Tap Volatile, I2C, Low-Voltage Linear

Taper Digital Potentiometer

www.maximintegrated.com Maxim Integrated

│

Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-layer

board. For detailed information on package thermal considerations, refer to www.maximintegrated.com/thermal-tutorial.

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.

Package Thermal Characteristics

Electrical Characteristics

(VDD = 1.7V to 5.5V, VH = V

DD, VL = GND, TA = -40°C to +125°C, unless otherwise noted. Typical values are at VDD = 1.8V,

TA = +25°C.) (Note 2)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

DC PERFORMANCE (Resistor Characteristics)

Terminal Capacitance CH, CLMeasured to GND 10 pF

Wiper Capacitance CWMeasured to GND 20 pF

End-to-End Resistor Tempco TCR No load 50 ppm/°C

End-to-End Resistor Tolerance Wiper not connected -25 +25 %

AC PERFORMANCE

-3dB Bandwidth BW Code = 80h, 10pF load,

VDD = 1.8V

10kΩ 1600

kHz

50kΩ 340

100kΩ 165

Total Harmonic Distortion Plus

Noise THD+N (Note 6) 0.035 %

Wiper Settling Time tS(Note 7)

10kΩ 190

50kΩ 400

100kΩ 664

Charge-Pump Feedthrough at W VRW 600 nVRMS

POWER SUPPLIES

Supply Voltage Range VDD 1.7 5.5 V

Terminal Voltage Range

(H, W, L to GND)

Charge pump enabled, 1.7V < VDD < 5.5V 05.25 V

Charge pump disabled, 2.6V < VDD < 5.5V 0VDD

Supply Current (Note 8) IVDD

Charge pump disabled, 1.7V 0.3 1.4

µA

Charge pump disabled, 2.5V 0.4 1.7

Charge pump disabled, 5.5V 1.0 4.0

Charge pump enabled,

1.7V < VDD < 5.5V

VDD = 5.5V 25 50

VDD = 1.7V 20 45

DIGITAL INPUTS

Minimum Input High Voltage VIH

2.6V < VDD < 5.5V 70 % x

VDD

1.7V < VDD < 2.6V 80

Maximum Input Low Voltage VIL

2.6V < VDD < 5.5V 30 % x

VDD

1.7V < VDD < 2.6V 20

Input Leakage Current -1 +1 µA

Input Capacitance 5pF

ADDR0 Pullup/Pulldown Strength RPURRPD (Note 9) 60 kΩ

TIMING CHARACTERISTICS (Note 10)

Maximum SCL Frequency fSCL 400 kHz

Setup Time for START Condition tSU:STA 0.6 µs

MAX5395 Single, 256-Tap Volatile, I2C, Low-Voltage Linear

Taper Digital Potentiometer

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Electrical Characteristics (continued)

(VDD = 1.7V to 5.5V, VH = V

DD, VL = GND, TA = -40°C to +125°C, unless otherwise noted. Typical values are at VDD = 1.8V,

TA = +25°C.) (Note 2)

Note 2: All devices are production tested at TA = +25°C and are guaranteed by design and characterization for TA = -40°C to

+125°C.

Note 3: DNL and INL are measured with the potentiometer configured as a voltage-divider with VH = 5.25V (QP enabled) or VDD

(QP disabled) and VL = GND. The wiper terminal is unloaded and measured with an ideal voltmeter.

Note 4: R-DNL and R-INL are measured with the potentiometer configured as a variable resistor (Figure 1). H is unconnected and

L = GND.

For charge pump enabled, VDD = 1.7V to 5.5V, 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 charge pump disabled and VDD = 5.5V, 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 charge pump disabled and VDD = 2.6V, 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 5: The wiper resistance is the maximum value measured by injecting the currents given in Note 4 into W with L = GND.

RW = (VW - VH)/IW.

Note 6: Measured at W with H driven with a 1kHz, 0V to VDD amplitude tone and VL = GND. 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 = VDD, L = GND, and

the wiper terminal is loaded with 10pF capacitance to ground.

Note 8: Digital Inputs at VDD or GND.

Note 9: An unconnected condition on the ADDR0 pin is sensed via a pullup and pulldown operation. For proper operation, the

ADDR0 pin should be tied to VDD, GND, or left unconnected with minimal capacitance.

Note 10: Digital timing is guaranteed by design and characterization, and is not production tested.

Figure 1. Voltage-Divider and Variable Resistor Configurations

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Hold Time for START Condition tHD:STA 0.6 µs

SCL High Time tHIGH 0.6 µs

SCL Low Time tLOW 1.3 µs

Data Setup Time tSU:DAT 100 ns

Data Hold Time tHD:DAT 0µs

SDA, SCL Rise Time tR0.3 µs

SDA, SCL Fall Time tF0.3 µs

Setup Time for STOP Conditions tSU:STO 0.6 µs

Bus Free Time Between STOP

and START Conditions tBUF 1.3 µs

Pulse-Suppressed Spike Width tSP 50 ns

Capacitive Load for Each Bus CB400 pF

N.C.

MAX5395 Single, 256-Tap Volatile, I2C, Low-Voltage Linear

Taper Digital Potentiometer

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Electrical Characteristics (continued)

(VDD = 1.8V, TA = +25°C, unless otherwise noted.)

SUPPLY CURRENT vs. TEMPERATURE

MAX5395 toc01

TEMPERATURE (°C)

SUPPLY CURRENT (μA)

1109580655035205-10-25

-40 125

VDD = 1.8V

RESISTANCE (W-TO-L)

vs. TAP POSITION (10kΩ)

MAX5395 toc04

TAP POSITION

W-TO-L RESISTANCE (kΩ)

0 256224192128 16064 9632

WIPER RESISTANCE

vs. WIPER VOLTAGE

WIPER VOLTAGE (V)

WIPER RESISTANCE (Ω)

0.5

0 1.0

MAX5395 toc07a

VDD = 2.6V, QP OFF

VDD = 5V, QP OFF

5.04.54.03.53.02.52.01.5

SUPPLY CURRENT

vs. DIGITAL INPUT VOLTAGE

MAX5395 toc02

DIGITAL INPUT VOLTAGE (V)

SUPPLY CURRENT (µA)

4321

200

400

600

800

1000

1200

1400

1600

1800

2000

2200

2400

2600

0 5

VDD = 5V

(LOW-HIGH)

VDD = 3.3V

(LOW-HIGH)

VDD = 1.8V

(LOW-HIGH)

VDD = 1.8V

(HIGH-LOW)

VDD = 3.3V

(HIGH-LOW)

VDD = 5V

(HIGH-LOW)

RESISTANCE (W-TO-L)

vs. TAP POSITION (50kΩ)

MAX5395 toc05

TAP POSITION

W-TO-L RESISTANCE (kΩ)

0 256224192128 16064 9632

WIPER RESISTANCE

vs. WIPER VOLTAGE

WIPER VOLTAGE (V)

WIPER RESISTANCE (Ω)

0.5

0 1.0

MAX5395 toc07b

VDD = 1.8V, QP ON

5.04.54.03.53.02.52.01.5

SUPPLY CURRENT vs. INPUT VOLTAGE

MAX5395 toc03

INPUT VOLTAGE (V)

4.553.602.651.70 5.50

SUPPLY CURRENT (μA)

TA = -40°C

TA = +25°C

TA = +125°C

RESISTANCE (W-TO-L)

vs. TAP POSITION (100kΩ)

MAX5395 toc06

TAP POSITION

W-TO-L RESISTANCE (kΩ)

100

0 256224192128 16064 9632

END-TO-END RESISTANCE PERCENTAGE

CHANGE vs. TEMPERATURE

MAX5395 toc08

TEMPERATURE (°C)

END-TO-END RESISTANCE PERCENTAGE CHANGE (%)

1109580655035205-10-25

-0.2

-40 125

0.2

0.4

0.6

0.8

50kΩ

10kΩ

100kΩ

MAX5395 Single, 256-Tap Volatile, I2C, Low-Voltage Linear

Taper Digital Potentiometer

Maxim Integrated

│

www.maximintegrated.com

Typical Operating Characteristics

(VDD = 1.8V, TA = +25°C, unless otherwise noted.)

TAP-TO-TAP SWITCHING TRANSIENT

(CODE 127 TO 128, 10kΩ)

MAX5395 toc09

200ns/div

VW-L

10mV/div

VSCL

2V/div

POWER-ON TRANSIENT (10kΩ)

MAX5395 toc12a

10µs/div

VW-L

1V/div

VDD

1V/div

MIDSCALE FREQUENCY

RESPONSE (10kΩ)

FREQUENCY (Hz)

GAIN (dB)

1M100k10k1k0.1k

-20

-10

-30

0.01k 10M

MAX5395 toc13

VDD = 1.8V

VDD = 5V

VIN = 1VP-P

CW = 10pF

TAP-TO-TAP SWITCHING TRANSIENT

(CODE 127 TO 128, 50kΩ)

MAX5395 toc10

200ns/div

VW-L

10mV/div

VSCL

2V/div

POWER-ON TRANSIENT (50kΩ)

MAX5395 toc12b

10µs/div

VW-L

1V/div

VDD

1V/div

MIDSCALE FREQUENCY

RESPONSE (50kΩ)

FREQUENCY (Hz)

GAIN (dB)

1M100k10k1k0.1k

-20

-10

-30

0.01k 10M

MAX5395 toc14

VDD = 1.8V

VDD = 5V

VIN = 1VP-P

CW = 10pF

TAP-TO-TAP SWITCHING TRANSIENT

(CODE 127 TO 128, 100kΩ)

MAX5395 toc11

200ns/div

VW-L

10mV/div

VSCL

2V/div

POWER-ON TRANSIENT (100kΩ)

MAX5395 toc12c

10µs/div

VW-L

1V/div

VDD

1V/div

MIDSCALE FREQUENCY

RESPONSE (100kΩ)

FREQUENCY (Hz)

GAIN (dB)

1M100k10k1k0.1k

-20

-10

-30

0.01k 10M

MAX5395 toc15

VDD = 1.8V

VDD = 5V

VIN = 1VP-P

CW = 10pF

MAX5395 Single, 256-Tap Volatile, I2C, Low-Voltage Linear

Taper Digital Potentiometer

Maxim Integrated

│

www.maximintegrated.com

Typical Operating Characteristics (continued)

(VDD = 1.8V, TA = +25°C, unless otherwise noted.)

TOTAL HARMONIC DISTORTION PLUS NOISE

vs. FREQUENCY

MAX5395 toc16

FREQUENCY (kHz)

THD+N (%)

1010.1

0.02

0.04

0.06

0.08

0.10

0.12

0.14

0.16

0.18

0.20

0.01 100

10kΩ50kΩ

100kΩ

CHARGE-PUMP FEEDTHROUGH AT W

MAX5395 toc17

FREQUENCY (MHz)

0.50 2.00

VOLTAGE (nVRMS)

100

200

300

400

500

600

700

800

900

1000

1.75

1.501.251.000.75

100kΩ

50kΩ

10kΩ

VARIABLE-RESISTOR DNL

vs. TAP POSITION (10kΩ)

MAX5395 toc18a

TAP POSITION

DNL (LSB)

-0.4

-0.3

-0.2

-0.1

0.1

0.2

0.3

0.4

0.5

-0.5

0 256224192128 16064 9632

VDD = 1.8V, VH = 5.0V, CHARGE PUMP ON

VDD = 2.6V, VH = 2.6V, CHARGE PUMP OFF

VDD = 5.0V, VH = 5.0V, CHARGE PUMP OFF

VARIABLE-RESISTOR INL

vs. TAP POSITION (10kΩ)

MAX5395 toc19a

TAP POSITION

INL (LSB)

-0.4

-0.3

-0.2

-0.1

0.1

0.2

0.3

0.4

0.5

-0.5

0256224192128 16064 9632

VDD = 2.6V,

VH = 2.6V,

CHARGE

PUMP OFF

VDD = 1.8V, VH = 5.0V, CHARGE PUMP ON

VDD = 5.0V, VH = 5.0V, CHARGE PUMP OFF

VARIABLE-RESISTOR DNL

vs. TAP POSITION (50kΩ)

MAX5395 toc18b

TAP POSITION

DNL (LSB)

-0.4

-0.3

-0.2

-0.1

0.1

0.2

0.3

0.4

0.5

-0.5

0 256224192128 16064 9632

VDD = 1.8V, VH = 5.0V, CHARGE PUMP ON

VDD = 2.6V, VH = 2.6V, CHARGE PUMP OFF

VDD = 5.0V, VH = 5.0V, CHARGE PUMP OFF

VARIABLE-RESISTOR INL

vs. TAP POSITION (50kΩ)

MAX5395 toc19b

TAP POSITION

INL (LSB)

-0.4

-0.3

-0.2

-0.1

0.1

0.2

0.3

0.4

0.5

-0.5

0256224192128 16064 9632

VDD = 2.6V, VH = 2.6V, CHARGE PUMP OFF

VDD = 1.8V, VH = 5.0V, CHARGE PUMP ON

VDD = 5.0V, VH = 5.0V, CHARGE PUMP OFF

VARIABLE-RESISTOR DNL

vs. TAP POSITION (100kΩ)

MAX5395 toc18c

TAP POSITION

DNL (LSB)

-0.4

-0.3

-0.2

-0.1

0.1

0.2

0.3

0.4

0.5

-0.5

0 256224192128 16064 9632

VDD = 1.8V, VH = 5.0V, CHARGE PUMP ON

VDD = 2.6V, VH = 2.6V, CHARGE PUMP OFF

VDD = 5.0V, VH = 5.0V, CHARGE PUMP OFF

VARIABLE-RESISTOR INL

vs. TAP POSITION (100kΩ)

MAX5395 toc19c

TAP POSITION

INL (LSB)

-0.4

-0.3

-0.2

-0.1

0.1

0.2

0.3

0.4

0.5

-0.5

0256224192128 16064 9632

VDD = 1.8V, VH = 5.0V, CHARGE PUMP ON

VDD = 2.6V, VH = 2.6V, CHARGE PUMP OFF

VDD = 5.0V, VH = 5.0V, CHARGE PUMP OFF

MAX5395 Single, 256-Tap Volatile, I2C, Low-Voltage Linear

Taper Digital Potentiometer

Maxim Integrated

│

www.maximintegrated.com

Typical Operating Characteristics (continued)

(VDD = 1.8V, TA = +25°C, unless otherwise noted.)

VOLTAGE-DIVIDER DNL

vs. TAP POSITION (10kΩ)

MAX5395 toc20a

TAP POSITION

DNL (LSB)

-0.4

-0.3

-0.2

-0.1

0.1

0.2

0.3

0.4

0.5

-0.5

0256224192128 16064 9632

VDD = 1.8V, VH = 5.0V, CHARGE PUMP ON

VDD = 2.6V, VH = 2.6V, CHARGE PUMP OFF

VDD = 5.0V, VH = 5.0V, CHARGE PUMP OFF

VOLTAGE-DIVIDER INL

vs. TAP POSITION (10kΩ)

MAX5395 toc21a

TAP POSITION

INL (LSB)

-0.4

-0.3

-0.2

-0.1

0.1

0.2

0.3

0.4

0.5

-0.5

0 256224192128 16064 9632

VDD = 1.8V, VH = 5.0V, CHARGE PUMP ON

VDD = 2.6V, VH = 2.6V, CHARGE PUMP OFF

VDD = 5.0V, VH = 5.0V, CHARGE PUMP OFF

VOLTAGE-DIVIDER DNL

vs. TAP POSITION (50kΩ)

MAX5395 toc20b

TAP POSITION

DNL (LSB)

-0.4

-0.3

-0.2

-0.1

0.1

0.2

0.3

0.4

0.5

-0.5

0256224192128 16064 9632

VDD = 1.8V, VH = 5.0V, CHARGE PUMP ON

VDD = 2.6V, VH = 2.6V, CHARGE PUMP OFF

VDD = 5.0V, VH = 5.0V, CHARGE PUMP OFF

VOLTAGE-DIVIDER INL

vs. TAP POSITION (50kΩ)

MAX5395 toc21b

TAP POSITION

INL (LSB)

-0.4

-0.3

-0.2

-0.1

0.1

0.2

0.3

0.4

0.5

-0.5

0 256224192128 16064 9632

VDD = 1.8V, VH = 5.0V, CHARGE PUMP ON

VDD = 2.6V, VH = 2.6V, CHARGE PUMP OFF

VDD = 5.0V, VH = 5.0V, CHARGE PUMP OFF

VOLTAGE-DIVIDER DNL

vs. TAP POSITION (100kΩ)

MAX5395 toc20c

TAP POSITION

DNL (LSB)

-0.4

-0.3

-0.2

-0.1

0.1

0.2

0.3

0.4

0.5

-0.5

0256224192128 16064 9632

VDD = 1.8V, VH = 5.0V, CHARGE PUMP ON

VDD = 2.6V, VH = 2.6V, CHARGE PUMP OFF

VDD = 5.0V, VH = 5.0V, CHARGE PUMP OFF

VOLTAGE-DIVIDER INL

vs. TAP POSITION (100kΩ)

MAX5395 toc21c

TAP POSITION

INL (LSB)

-0.4

-0.3

-0.2

-0.1

0.1

0.2

0.3

0.4

0.5

-0.5

0 256224192128 16064 9632

VDD = 1.8V, VH = 5.0V, CHARGE PUMP ON

VDD = 2.6V, VH = 2.6V, CHARGE PUMP OFF

VDD = 5.0V, VH = 5.0V, CHARGE PUMP OFF

MAX5395 Single, 256-Tap Volatile, I2C, Low-Voltage Linear

Taper Digital Potentiometer

Maxim Integrated

│

www.maximintegrated.com

Typical Operating Characteristics (continued)

PIN NAME FUNCTION

1 L Low Terminal. The voltage at L can be greater than or less than the voltage at H. Current can flow into or out

of L.

2GND Ground

3ADDR0 Address Input 0. Connected to VDD, GND, or open.

4SDA I2C Serial Data Input

5SCL I2C Clock Input

6VDD Power Supply

7WWiper Terminal

8HHigh Terminal. The voltage at H can be greater than or less than the voltage at L. Current can flow into or

out of H.

—EP Exposed Pad. Internally connected to GND. Connect to ground.

SCL

MAX5395

SDA

GND

TDFN

TOP VIEW

ADDR0

MAX5395 Single, 256-Tap Volatile, I2C, Low-Voltage Linear

Taper Digital Potentiometer

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│

Pin Description

Pin Conguration

Detailed Description

The MAX5395 single, 256-tap volatile, low-voltage

linear taper digital potentiometer offers three end-to-

end resistance values of 10kΩ, 50kΩ, and 100kΩ.

Potentiometer terminals are independent of supply for

voltages up to +5.25V with single-supply operation from

1.7V to 5.5V (charge pump enabled). User-controlled

shutdown modes allow the H, W, or L terminals to be

opened with the wiper position set to zero-code, midcode,

full-code, or the value contained in the wiper register. Ultra-

low-quiescent supply current (< 1µA) can be achieved for

supply voltages between 2.6V and 5.5V by disabling the

internal charge pump and not allowing potentiometer

terminals to exceed the supply voltage by more than

0.3V. The MAX5395 provides a low 50ppm/°C end-to-end

temperature coefficient and features a I2C serial interface.

The small package size, low supply operating voltage,

low supply current, and automotive temperature range

of the MAX5395 make the device uniquely suited for the

portable consumer market and battery-backup industrial

applications.

Charge Pump

The MAX5395 contains an internal charge pump that

guarantees the maximum wiper resistance, RWL, to be

less than 50Ω (25Ω typ) for supply voltages down to

1.7V and allows pins H, W, and L to be driven between

GND and 5.25V independent of VDD. Minimal charge-

pump feedthrough is present at the terminal outputs

and is illustrated by the Charge-Pump Feedthrough

at W vs. Frequency graph in the Typical Operating

Characteristics. The charge pump is on by default but

can be disabled with QP_OFF and enabled with the

QP_ON commands (Table 1). The MAX5395 minimum

supply voltage with charge pump disabled is limited

to 2.6V and terminal voltage cannot exceed -0.3V to

(VDD + 0.3V).

I2C Interface

The MAX5395 feature an I2C/SMBus-compatible, 2-wire

serial interface consisting of a serial data line (SDA) and

a serial clock line (SCL). SDA and SCL enable communication

between the MAX5395 and the master at clock rates up

to 400kHz. Figure 1 shows the 2-wire interface timing

diagram. The master generates SCL and initiates data

transfer on the bus. The master device writes data to the

MAX5395 by transmitting the proper slave address fol-

lowed by the command byte and then the data word. Each

transmit sequence is framed by a START (S) or Repeated

START (Sr) condition and a STOP (P) condition. Each

word transmitted to the MAX5395 is 8 bits long and is fol-

lowed by an acknowledge clock pulse. A master reading

data from the MAX5395 must transmit the proper slave

address followed by a series of nine SCL pulses for each

byte of data requested. The MAX5395 transmit data on

SDA in sync with the master-generated SCL pulses. The

master acknowledges receipt of each byte of data. Each

read sequence is framed by a START or Repeated START

condition, a not acknowledge, and a STOP condition. SDA

operates as both an input and an open-drain output. A pullup

resistor, typically 4.7kΩ, is required on SDA. SCL operates

only as an input. A pullup resistor, typically 4.7kΩ, is required

on SCL if there are multiple masters on the bus, or if the

single master has an open-drain SCL output.

Series resistors in line with SDA and SCL are optional.

Series resistors protect the digital inputs of the MAX5395

from high voltage spikes on the bus lines and mini-

mize crosstalk and undershoot of the bus signals. The

MAX5395 can accommodate bus voltages higher than

VDD up to a limit of +5.5V. Bus voltages lower than VDD

are not recommended and may result in significantly

increased interface currents and data corruption.

The MAX5395 with I2C interface contains a shift register

that decodes the command and address bytes, routing

the data to the register. Data written to a memory register

immediately updates the wiper position. The wiper powers

up in mid position, D[7:0] = 0x80 with charge pump enabled.

ADDRO

GND

SDA

VDD

SCL

MAX5395

I2C

INTERFACE

MAX5395 Single, 256-Tap Volatile, I2C, Low-Voltage Linear

Taper Digital Potentiometer

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Functional Diagram

I2C START and STOP Conditions

SDA and SCL idle high when the bus is not in use. A master

initiates communication by issuing a START condition. A

START condition is a high-to-low transition on SDA with

SCL high. A STOP condition is a low-to-high transition on

SDA while SCL is high (Figure 2). A START condition from

the master signals the beginning of a transmission to the

MAX5395. The master terminates transmission and frees

the bus, by issuing a STOP condition. The bus remains

active if a Repeated START condition is generated instead

of a STOP condition.

I2C Early STOP and Repeated START Conditions

The MAX5395 recognizes a STOP condition at any point

during data transmission except if the STOP condition

occurs in the same high pulse as a START condition.

For proper operation, do not send a STOP condition

during the same SCL high pulse as the START condition.

Transmissions ending in an early STOP condition will not

impact the internal device settings. If the STOP occurs

during a readback byte, the transmission is terminated

and a later read mode request will begin transfer of the

requested register data from the beginning. See Figure 3.

It is possible to interrupt a transmission to a MAX5395

with a new START (Repeated START) condition (perhaps

addressing another device), which leaves the input registers

with data that has not been transferred to the internal

registers. The unused data will not be stored under these

conditions. The aborted MAX5395 I2C sequence will have

no effect on the part.

I2C Acknowledge

In write mode, the acknowledge bit (ACK) is a clocked

9th bit that the MAX5395 uses to handshake receipt of

each byte of data as shown in Figure 4. The MAX5395

pulls down SDA during the entire master-generated 9th

clock pulse if the previous byte is successfully received.

Monitoring ACK allows for detection of unsuccessful data

transfers. An unsuccessful data transfer occurs if a receiving

device is busy or if a system fault has occurred. In the

event of an unsuccessful data transfer, the bus master will

retry communication.

Figure 2. I2C Timing Diagram

Figure 3. I2C START(s), Repeated START(S), and STOP(S) Conditions

SDA

SCL

START

CONDITION

(S)

LOW

BUF

HIGH

HD:STA

SU:DAT

SU:STD

REPEATED

START CONDITION

(Sr)

ACKNOWLEDGE (A) STOP CONDITION

(P)

START CONDITION

(S)

HD-DAT

SU:DTA

SCL

SDA

S Sr P

VALID START, REPEATED START, AND STOP PULSES

P S PS P PS

INVALID START/STOP PULSE PAIRINGS-ALL WILL BE RECOGNIZED AS STARTS

MAX5395 Single, 256-Tap Volatile, I2C, Low-Voltage Linear

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In read mode, the master pulls down SDA during the

9th clock cycle to acknowledge receipt of data from the

MAX5395. An acknowledge is sent by the master after

each read byte to allow data transfer to continue. A not-

acknowledge is sent when the master reads the final byte

of data from the MAX5395, followed by a STOP condition.

I2C Slave Address

The slave address is defined as the seven most significant

bits (MSBs) followed by the R/W bit. See Figure 5 and

Figure 6. The five most significant bits are 01010 with the

3 LSBs determined ADDR0 as shown in Table 1. Setting

the R/W bit to 1 configures the MAX5395 for read mode.

Setting the R/W bit to 0 configures the MAX5395 for write

mode. The slave address is the first byte of information

sent to the MAX5395 after the START condition.

The MAX5395 has the ability to detect an unconnected

(N.C.) state on the ADDR0 input for additional address

flexibility; if disconnecting the ADDR0 input, be certain to

minimize all loading on the ADDR0 input (i.e. provide a

landing for ADDR0, but do not allow any board traces).

I2C Message Format for Writing

A master device communicates with the MAX5395 by

transmitting the proper slave address followed by command

and data word. Each transmit sequence is framed by a

START or Repeated START condition and a STOP condition as

described above. Each word is 8 bits long and is always

followed by an acknowledge clock (ACK) pulse as shown

in Figure 5. The first byte contains the address of the

MAX5395 with R/W = 0 to indicate a write. The second

byte contains the command to be executed and the third

byte contains the data to be written.

I2C Message Format for Readback Operations

Each readback sequence is framed by a START or

Repeated START condition and a STOP condition. Each

word is 8 bits long and is followed by an acknowledge

clock pulse as shown in Figure 6. The first byte contains

the address of the MAX5395 with R/W = 0 to indicate a

write. The second byte contains the register that is to

be read back. There is a Repeated START condition,

followed by the device address with R/W = 1 to indicate a

Table 1. I2C Slave Address LSBs

Figure 5. I2C Complete Write Serial Transmission

Figure 4. I2C Acknowledge

ADDR0 A1 A0 SLAVE ADDRESS

GND 0 0 0101000

N.C. 0 1 0101001

VDD 1 1 0101011

0 1 0 1 0 A1 A0 W D D D D D D D DA A ASEE REGISTER OPTIONS

SDA

START STOP

WRITE ADDRESS

BYTE #1: I2C SLAVE ADDRESS

WRITE REGISTER

BYTE #2: REG # = N

WRITE DATA

BYTE #3: DATA BYTE B[7:0]

SCL

REG N UPDATED

ACK. GENERATED BY MAX5395L/

MAX5395M/MAX5395N

ACK. GENERATED BY I2C MASTER

SCL

START

CONDITION

SDA

2 9

CLOCK PULSE

FOR

ACKNOWLEDGMENT

ACKNOWLEDGE

NOT ACKNOWLEDGE

MAX5395 Single, 256-Tap Volatile, I2C, Low-Voltage Linear

Taper Digital Potentiometer

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read and an acknowledge clock. The master has control

of the SCL line but the MAX5395 takes over the SDA

line. The final byte in the frame contains the register data

readback followed by a STOP condition. If additional

bytes beyond those required to read back the requested

data are provided, the MAX5395 will continue to read

back ones.

The wiper register and the configuration register are

the only two registers that support readback (Table 2).

Readback of all other registers is not supported and

results in the readback of ones.

D[7:0]: Wiper position

QP: Charge pump status, 1 is enabled, 0 is disabled.

HSW: H terminal switch status, 0 is closed, 1 is open

WSW: W terminal switch status, 0 is closed, 1 is open

LSW: L terminal switch status, 0 is closed, 1 is open

TSEL[1:0]: Tap select, 00- wiper is at contents of wiper

wiper is at 0xFF.

General Call Support

The MAX5395 supports software reset through general

call address 0x00 followed by R/W = 0, followed by 0x06

data. A software reset of the MAX5395 will return the part

to the power-on default conditions. The MAX5395 will

ACK the general call address and any command byte

following, but will not support any general call features

other than software reset.

Figure 6. Standard I2C Register Read Sequence

Table 2. I2C READ Command Byte Summary

C7 C6 C5 C4 C3 C2 C1 C0 D7 D6 D5 D4 D3 D2 D1 D0

WIPER 00000000D7 D6 D5 D4 D3 D2 D1 D0

CONFIG 10000000QP 0 0 HSW LSW WSW TSEL[1:0]

0 1 0 1 0 A1 A0 W 0 D D D D D D D D ~A1 0 1 0A A A1 A0 R ASEE REGISTER OPTIONSSDA

START STOP

WRITE ADDRESS

BYTE #1: I2C SLAVE ADDRESS

WRITE COMMAND

BYTE #2: COMMAND BYTE

READ ADDREESS

BYTE #3: I2C SLAVE ADDRESS

READ DATA

BYTE #4: DATA BYTE B[7:0]

REPEATED

START

SCL

ACK. GENERATED BY MAX5395L/

MAX5395M/MAX5395N

ACK. GENERATED BY I2C MASTER

MAX5395 Single, 256-Tap Volatile, I2C, Low-Voltage Linear

Taper Digital Potentiometer

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WIPER Command

The data byte writes to the wiper register and the

potentiometer moves to the appropriate position. D[7:0]

indicates the position of the wiper. D[7:0] = 0x00 moves

the wiper to the position closest to L. D[7:0] = 0xFF moves

the wiper closest to H. D[7:0] = 0x80 following power-on.

SD_CLR Command

Removes any existing shutdown condition. Connects all

potentiometer terminals and returns the wiper to the value

stored in the wiper register. The command does not affect

the current status of the charge pump.

SD_H_WREG Command

Opens the H terminal and maintains the wiper at the

wiper register location. Writes cannot be made to the

wiper register while shutdown mode is engaged. Clearing

shutdown mode will close the H terminal and allow the

wiper register to be written. A RST will also deassert

shutdown mode and return the wiper to midscale (0x80).

This command does not affect the charge-pump status.

SD_H_ZERO Command

Moves wiper to zero-scale position (0x00) and opens the

H terminal. The wiper register remains unaltered. Writes

cannot be made to the wiper register while shutdown

mode is engaged. Clearing shutdown mode will return the

wiper to the position contained in the wiper register and

close the H terminal. A RST will also deassert shutdown

mode and return the wiper to midscale (0x80). This

command does not affect the charge-pump status.

SD_H_MID Command

Moves wiper to midscale position (0x80) and opens the

H terminal. The wiper register remains unaltered. Writes

cannot be made to the wiper register while shutdown

mode is engaged. Clearing shutdown mode will return the

wiper to the position contained in the wiper register and

close the H terminal. A RST will also deassert shutdown

mode and return the wiper to midscale (0x80). This

command does not affect the charge-pump status.

SD_H_FULL Command

Moves wiper to full-scale position (0xFF) and opens the

H terminal. The wiper register remains unaltered. Writes

cannot be made to the wiper register while shutdown

mode is engaged. Clearing shutdown mode will return the

wiper to the position contained in the wiper register and

close the H terminal. A RST will also deassert shutdown

mode and return the wiper to midscale (0x80). This

command does not affect the charge-pump status.

Table 3. I2C Write Command Byte Summary

COMMAND ADDRESS BYTE COMMAND BYTE DATA BYTE

A6 A5 A4 A3 A2 A1 A0 R/W

C7 C6 C5 C4 C3 C2 C1 C0

D7 D6 D5 D4 D3 D2 D1 D0

A P

WIPER

See Table 1

0 00000000 D7 D6 D5 D4 D3 D2 D1 D0

SD_CLR 0 10000000

Don’t Care

SD_H_WREG 0 10010000

SD_H_ZERO 0 10010001

SD_H_MID 0 10010010

SD_H_FULL 0 10010011

SD_L_WREG 0 10001000

SD_L_ZERO 0 10001001

SD_L_MID 0 10001010

SD_L_FULL 0 10001011

SD_W 0 100001XX

QP_OFF 0 10100000

QP_ON 0 10100001

RST 0 11000000

MAX5395 Single, 256-Tap Volatile, I2C, Low-Voltage Linear

Taper Digital Potentiometer

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SD_L_WREG Command

Opens the L terminal and maintains the wiper at the

wiper register location. Writes cannot be made to the

wiper register while shutdown mode is engaged. Clearing

shutdown mode will close the L terminal and allow wiper

mode and return the wiper to midscale (0x80). This

command does not affect the charge-pump status.

SD_L_ZERO Command

Moves wiper to zero-scale position (0x00) and opens the

L terminal. The wiper register remains unaltered. Writes

cannot be made to the wiper register while shutdown

mode is engaged. Clearing shutdown mode will return the

wiper to the position contained in the wiper register and

close the L terminal. A RST will also deassert shutdown

mode and return the wiper to midscale (0x80). This

command does not affect the charge-pump status.

SD_L_MID Command

Moves wiper to midscale position (0x80) and opens the

L terminal. The wiper register remains unaltered. Writes

cannot be made to the wiper register while shutdown

mode is engaged. Clearing shutdown mode will return the

wiper to the position contained in the wiper register and

close the L terminal. A RST will also deassert shutdown

mode and return the wiper to midscale (0x80). This

command does not affect the charge-pump status.

SD_L_FULL Command

Moves wiper to full-scale position (0xFF) and opens the

L terminal. The wiper register remains unaltered. Writes

cannot be made to the wiper register while shutdown

mode is engaged. Clearing shutdown mode will return the

wiper to the position contained in the wiper register and

close the L terminal. A RST will also deassert shutdown

mode and return the wiper to midscale (0x80). This

command does not affect the charge-pump status.

SD_W Command

Opens the W terminal keeping the internal tap position

the same as the wiper register. Writes cannot be made

to the wiper registers while shutdown mode is engaged.

Clearing shutdown mode will return the wiper to the

position contained in the wiper register and close W

terminal. A RST will also deassert shutdown mode and

return the wiper to midscale (0x80). This command does

not affect the charge-pump status.

QP_OFF Command

Disables the onboard charge pump and places device in

low power mode. Low supply voltage is limited to 2.6V.

QP_ON Command

Enables the onboard charge pump to allow low-supply

voltage operation. This is the power-on default condition.

Low supply voltage is 1.7V.

RST Command

Returns the device to power-on default conditions. Resets

the wiper register to midscale (0x80), enables charge

pump, and deasserts any shutdown modes.

MAX5395 Single, 256-Tap Volatile, I2C, Low-Voltage Linear

Taper Digital Potentiometer

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Note: All devices operate over the -40°C to +125°C temperature range.

+Denotes a lead(Pb)-free/RoHS-compliant package.

T = Tape and reel.

*EP = Exposed pad.

PART PIN-PACKAGE INTERFACE TAPS END-TO-END

RESISTANCE (kΩ)

MAX5395LATA+T 8 TDFN-EP* I2C256 10

MAX5395MATA+T 8 TDFN-EP* I2C256 50

MAX5395NATA+T 8 TDFN-EP* I2C256 100

PACKAGE

TYPE

PACKAGE

CODE

OUTLINE

NO.

LAND PATTERN

NO.

8 TDFN-EP T822+2 21-0168 90-0065

MAX5395 Single, 256-Tap Volatile, I2C, Low-Voltage Linear

Taper Digital Potentiometer

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Package Information

For the latest package outline information and land patterns

(footprints), go to www.maximintegrated.com/packages. Note

that a “+”, “#”, or “-” in the package code indicates RoHS status

only. Package drawings may show a different suffix character, but

the drawing pertains to the package regardless of RoHS status.

Chip Information

PROCESS: BiCMOS

Ordering Information

REVISION

NUMBER

REVISION

DATE DESCRIPTION PAGES

CHANGED

07/12 Initial release —

19/12 Revised the Absolute Maximum Ratings 2

211/14 Removed automotive references from data sheet 1, 10

32/16 Add charge pump current at various disabled conditions 3

Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses

are implied. Maxim Integrated reserves the right to change the circuitry and specications without notice at any time. The parametric values (min and max limits)

shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance.

Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc.

MAX5395 Single, 256-Tap Volatile, I2C, Low-Voltage Linear

Taper Digital Potentiometer

│

Revision History

For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim Integrated’s website at www.maximintegrated.com.