Analog Devices AD5170 a Datasheet

256-Position Two-Time Programmable

G

2

I

C Digital Potentiometer

FEATURES

256-position
TTP (two-time programmable) set-and-forget resistance

setting allows second-chance permanent programming

Unlimited adjustments prior to OTP (one-time

programming) activation

OTP overwrite allows dynamic adjustments with user

defined preset
End-to-end resistance: 2.5 kΩ, 10 kΩ, 50 kΩ, 100 kΩ
Compact MSOP-10 (3 mm × 4.9 mm) package
Fast settling time: t
Full read/write of wiper register
Power-on preset to midscale
Extra package address decode pins AD0 and AD1
Single-supply 2.7 V to 5.5 V
Low temperature coefficient: 35 ppm/°C
Low power, I
Wide operating temperature: –40°C to +125°C
Evaluation board and software are available
Software replaces µC in factory programming applications

APPLICATIONS

Systems calibration
Electronics level setting
Mechanical Trimmers® replacement in new designs
Permanent factory PCB setting
Transducer adjustment of pressure, temperature, position,

chemical, and optical sensors
RF amplifier biasing
Automotive electronics adjustment
Gain control and offset adjustment

GENERAL OVERVIEW

The AD5170 is a 256-position, two-time programmable (TTP)
digital potentiometer
enable two opportunities at permanently programming the
resistance setting. OTP is a cost-effective alternative to EEMEM
for users who do not need to program the digital potentiometer
setting in memory more than once. This device performs the
same electronic adjustment function as mechanical
potentiometers or variable resistors with enhanced resolution,
solid-state reliability, and superior low temperature coefficient
performance.

= 5 µs typ in power-up

S

= 6 µA maximum

DD

1

that employs fuse link technology to

AD5170

FUNCTIONAL BLOCK DIAGRAM

W

BA

V

DD

ND

AD0

AD1

SDA

SCL

12

ADDRESS

DECODE

The AD5170 is programmed using a 2-wire, I2C® compatible
digital interface. Unlimited adjustments are allowed before
permanently (there are actually two opportunities) setting the
resistance value. During OTP activation, a permanent blow fuse
command freezes the wiper position (analogous to placing
epoxy on a mechanical trimmer).

Unlike traditional OTP digital potentiometers, the AD5170 has
a unique temporary OTP overwrite feature that allows for new
adjustments even after the fuse has been blown. However, the
OTP setting is restored during subsequent power-up
conditions. This feature allows users to treat these digital
potentiometers as volatile potentiometers with a programmable
preset.

For applications that program the AD5170 at the factory,
Analog Devices offers device programming software running
on Windows NT®, 2000, and XP® operating systems. This
software effectively replaces any external I
enhancing the time-to-market of the user’s systems.

1

The terms digital potentiometer, VR, and RDAC are used interchangeably.

FUSE

LINKS

RDAC

REGISTER

SERIAL INPUT

REGISTER

Figure 1.

/

8

04104-0-001

2

C controllers, thus

Rev. A

Information furnished by Analog Devices is believed to be accurate and reliable.
However, no responsibility is assumed by Analog Devices for its use, nor for any
infringements of patents or other rights of third parties that may result from its use.
Specifications subject to change without notice. No license is granted by implication
or otherwise under any patent or patent rights of Analog Devices. Trademarks and
registered trademarks are the property of their respective owners.

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: [phone]
Fax: [phone] © 2004 Analog Devices, Inc. All rights reserved.

www.analog.com

AD5170

TABLE OF CONTENTS

Electrical Characteristics — 2.5 kΩ ............................................... 3

Electrical Characteristics — 10 kΩ, 50 kΩ, 100 kΩ Versions..... 4

Timing Characteristics — 2.5 kΩ, 10 kΩ, 50 kΩ, 100 kΩ

Versions.............................................................................................. 5

Absolute Maximum Ratings............................................................ 6

ESD Caution.................................................................................. 6

Typical Performance Characteristics ............................................. 7

Test Circuits..................................................................................... 11

Theory of Operation ...................................................................... 12

One-Time Programming (OTP).............................................. 12

Programming the Variable Resistor and Voltage ................... 12

Programming the Potentiometer Divider............................... 13

ESD Protection ........................................................................... 14

REVISION HISTORY

11/04—Data Sheet Changed from Rev. 0 to Rev. A

Changes to Electrical Characteristics Table 1............................... 3

Changes to Electrical Characteristics Table 2............................... 4

Changes to One-Time Programming ......................................... 12

Changes to Figure 37, Figure 38, and Figure 39 ........................ 14

Changes to Power Supply Considerations................................... 14

Changes to Figure 40...................................................................... 15

Changes to Layout Considerations .............................................. 15

Terminal Voltage Operating Range ......................................... 14

Power-Up Sequence................................................................... 14

Power Supply Considerations................................................... 14

Layout Considerations............................................................... 15

Evaluation Software/Hardware..................................................... 16

Software Programming ............................................................. 16

2

I

C Interface .................................................................................... 18

2

I

C Compatible 2-Wire Serial Bus ........................................... 20

Pin Configuration and Function Descriptions........................... 22

Outline Dimensions....................................................................... 23

Ordering Guide .......................................................................... 23

11/03—Revision 0: Initial Version

Rev. A | Page 2 of 24

AD5170

ELECTRICAL CHARACTERISTICS — 2.5 kΩ

VDD = 5 V ± 10% or 3 V ±10%, VA = +VDD, VB = 0 V, –40°C < TA < +125°C, unless otherwise noted.

Table 1.

Parameter Symbol Conditions Min Typ1 Max Unit

DC CHARACTERISTICS—RHEOSTAT MODE

Resistor Differential Nonlinearity2 R-DNL RWB, VA = no connect –2 ±0.1 +2 LSB
Resistor Integral Nonlinearity2 R-INL RWB, VA = no connect –6 ±0.75 +6 LSB
Nominal Resistor Tolerance3 ∆RAB T
Resistance Temperature Coefficient (∆RAB/RAB)/∆T VAB = VDD, Wiper = no connect 35 ppm/°C
RWB (Wiper Resistance) RWB Code = 0x00, VDD = 5 V 160 200 Ω

DC CHARACTERISTICS — POTENTIOMETER DIVIDER MODE (Specifications apply to all VRs)

Differential Nonlinearity4 DNL –1.5 ±0.1 +1.5 LSB
Integral Nonlinearity4 INL –2 ±0.6 +2 LSB
Voltage Divider Temperature Coefficient (∆VW/VW)/∆T Code = 0x80 15 ppm/°C
Full-Scale Error V
Zero-Scale Error V

Code = 0xFF –10 –2.5 0 LSB

WFSE

Code = 0x00 0 2 10 LSB

WZSE

RESISTOR TERMINALS

Voltage Range5 V

GND VDD V

A,VB,VW

Capacitance6 A, B CA, CB f = 1 MHz, measured to GND, code = 0x80 45 pF
Capacitance W CW f = 1 MHz, measured to GND, code = 0x80 60 pF
Shutdown Supply Current7 I

V

A_SD

Common-Mode Leakage ICM V

DIGITAL INPUTS AND OUTPUTS

Input Logic High VIH V
Input Logic Low VIL V
Input Logic High VIH V
Input Logic Low VIL V
Input Current IIL V
Input Capacitance5 C

5 pF

IL

POWER SUPPLIES

Power Supply Range V
OTP Supply Voltage V

2.7 5.5 V

DD RANGE

T

DD_OTP

Supply Current IDD V
OTP Supply Current I
Power Dissipation8 P

V

DD_OTP

V

DISS

Power Supply Sensitivity PSS VDD = 5 V ± 10%, Code = midscale ±0.02 ±0.08 %/%

DYNAMIC CHARACTERISTICS9

Bandwidth –3 dB BW_2.5K Code = 0x80 4.8 MHz
Total Harmonic Distortion THDW V
VW Settling Time tS V
Resistor Noise Voltage Density e

1

Typical specifications represent average readings at 25°C and VDD = 5 V.

2

Resistor position nonlinearity error, R-INL, is the deviation from an ideal value measured between the maximum resistance and the minimum resistance wiper

positions. R-DNL measures the relative step change from ideal between successive tap positions. Parts are guaranteed monotonic.

3

VAB = VDD, Wiper (VW) = no connect.

4

INL and DNL are measured at VW with the RDAC configured as a potentiometer divider similar to a voltage output D/A converter. VA = VDD and VB = 0 V.

DNL specification limits of ±1 LSB maximum are guaranteed monotonic operating conditions.

5

Resistor terminals A, B, W have no limitations on polarity with respect to each other.

6

Guaranteed by design and not subject to production test.

7

Measured at the A terminal. The A terminal is open circuited in shutdown mode.

8

P

is calculated from (IDD × VDD). CMOS logic level inputs result in minimum power dissipation.

DISS

9

All dynamic characteristics use VDD = 5 V.

R

N_WB

= 25°C –20 +55 %

A

= 5.5 V 0.01 1 µA

DD

= VB = VDD/2 1 nA

A

= 5 V 2.4 V

DD

= 5 V 0.8 V

DD

= 3 V 2.1 V

DD

= 3 V 0.6 V

DD

= 0 V or 5 V ±1 µA

IN

= 25°C 5.25 5.5 V

A

= 5 V or VIL = 0 V 3.5 6 µA

IH

= 5.5 V, TA = 25°C 100 mA

DD_OTP

= 5 V or VIL = 0 V, VDD = 5 V 30 µW

IH

= 1 V rms, VB = 0 V, f = 1 kHz 0.1 %

A

= 5 V, VB = 0 V, ±1 LSB error band 1 µs

A

= 1.25 kΩ, RS = 0 3.2 nV/√Hz

WB

Rev. A | Page 3 of 24

AD5170

ELECTRICAL CHARACTERISTICS — 10 kΩ, 50 kΩ, 100 kΩ VERSIONS

VDD = 5 V ± 10% or 3 V ± 10%, VA = VDD; VB = 0 V, –40°C < TA < +125°C, unless otherwise noted.

Table 2.

Parameter Symbol Conditions Min Typ1 Max Unit

DC CHARACTERISTICS—RHEOSTAT MODE

Resistor Differential Nonlinearity2 R-DNL RWB, VA = no connect –1 ±0.1 +1 LSB
Resistor Integral Nonlinearity2

R-INL R
Nominal Resistor Tolerance3 ∆RAB T
Resistance Temperature Coefficient (∆RAB/RAB)/∆T VAB = VDD, wiper = no connect 35 ppm/°C
RWB (Wiper Resistance) RWB Code = 0x00, VDD = 5 V 160 200 Ω

DC CHARACTERISTICS — POTENTIOMETER DIVIDER MODE (Specifications apply to all VRs)

Differential Nonlinearity4 DNL –1 ±0.1 +1 LSB
Integral Nonlinearity4
Voltage Divider Temperature

INL –1 ±0.3 +1 LSB

(∆VW/VW)/∆T

Coefficient
Full-Scale Error V
Zero-Scale Error V

Code = 0xFF –2.5 –1 0 LSB

WFSE

Code = 0x00 0 1 2.5 LSB

WZSE

RESISTOR TERMINALS

Voltage Range5
Capacitance6 A, B
Capacitance6 W
Shutdown Supply Current7 I

VA,VB,VW
CA, CB

C

f = 1 MHz, measured to GND, code = 0x80 60 pF

W

V

A_SD

Common-Mode Leakage ICM V

DIGITAL INPUTS AND OUTPUTS

Input Logic High VIH V
Input Logic Low VIL V
Input Logic High VIH V
Input Logic Low VIL V
Input Current IIL V

C

Input Capacitance6

5 pF

IL

POWER SUPPLIES

Power Supply Range V
OTP Supply Voltage8 V

2.7 5.5 V

DD RANGE

5.25 5.5 V

DD_OTP

Supply Current IDD V
OTP Supply Current9 I
Power Dissipation10 P

DD_OTP

V

DISS

Power Supply Sensitivity PSS VDD = 5 V ± 10%, code = midscale ±0.02 ±0.08 %/%

DYNAMIC CHARACTERISTICS11

Bandwidth –3 dB BW RAB = 10 kΩ, code = 0x80 600 kHz
R
R
Total Harmonic Distortion THDW V
VW Settling Time

tS V

(10 kΩ/50 kΩ/100 kΩ)
Resistor Noise Voltage Density e

1

Typical specifications represent average readings at 25°C and VDD = 5 V.

2

Resistor position nonlinearity error, R-INL, is the deviation from an ideal value measured between the maximum resistance and the minimum resistance wiper

positions. R-DNL measures the relative step change from ideal between successive tap positions. Parts are guaranteed monotonic.

3

VAB = VDD, Wiper (VW) = no connect.

4

INL and DNL are measured at VW with the RDAC configured as a potentiometer divider similar to a voltage output D/A converter. VA = VDD and VB = 0 V.

DNL specification limits of ±1 LSB maximum are guaranteed monotonic operating conditions.

5

Resistor terminals A, B, W have no limitations on polarity with respect to each other.

6

Guaranteed by design and not subject to production test.

7

Measured at the A terminal. The A terminal is open circuited in shutdown mode.

8

Different from operating power supply, power supply OTP is used one time only.

9

Different from operating current, supply current for OTP lasts approximately 400 ms for one time only.

10

P

is calculated from (IDD × VDD). CMOS logic level inputs result in minimum power dissipation.

DISS

11

All dynamic characteristics use VDD = 5 V.

R

N_WB

, VA = no connect –2.5 ±0.25 +2.5 LSB

WB

= 25°C –20 +20 %

A

Code = 0x80 15 ppm/°C

GND VDD V
f = 1 MHz, measured to GND, code = 0x80 45 pF

= 5.5 V 0.01 1 µA

DD

= VB = VDD/2 1 nA

A

= 5 V 2.4 V

DD

= 5 V 0.8 V

DD

= 3 V 2.1 V

DD

= 3 V 0.6 V

DD

= 0 V or 5 V ±1 µA

IN

= 5 V or VIL = 0 V 3.5 6 µA

IH

V

= 5.5 V, TA = 25°C

DD_OTP

= 5 V or VIL = 0 V, VDD = 5 V 30 µW

IH

= 50 kΩ, code = 0x80 100 kHz

AB

= 100 kΩ, code = 0x80 40 kHz

AB

=1 V rms, VB = 0 V, f = 1 kHz, RAB = 10 kΩ 0.1 %

A

= 5 V, VB = 0 V, ±1 LSB error band 2 µs

A

= 5 kΩ, RS = 0 9 nV/√Hz

WB

100 mA

Rev. A | Page 4 of 24

AD5170

TIMING CHARACTERISTICS — 2.5 kΩ, 10 kΩ, 50 kΩ, 100 kΩ VERSIONS

VDD = 5 V ± 10% or 3 V ± 10%, VA = VDD; VB = 0 V, –40°C < TA < +125°C, unless otherwise noted.

Table 3.

Parameter Symbol Conditions Min Typ Max Unit

I2C INTERFACE TIMING CHARACTERISTICS1 (Specifications apply to all parts)

SCL Clock Frequency f
t

Bus Free Time between STOP and START t1 1.3 µs

BUF

t

Hold Time (Repeated START) t2

HD;STA

t

Low Period of SCL Clock t3 1.3 µs

LOW

t

High Period of SCL Clock t4 0.6 µs

HIGH

t

Setup Time for Repeated START Condition t5 0.6 µs

SU;STA

t

Data Hold Time2 t

HD;DAT

t

Data Setup Time t7 100 ns

SU;DAT

tF Fall Time of Both SDA and SCL Signals t8 300 ns
tR Rise Time of Both SDA and SCL Signals t9 300 ns
t

Setup Time for STOP Condition t10 0.6 µs

SU;STO

1

See timing diagrams for locations of measured values.

2

The maximum t

has only to be met if the device does not stretch the LOW period (t

HD;DAT

400 kHz

SCL

After this period, the first clock

0.6 µs

pulse is generated.

0.9 µs

6

) of the SCL signal.

LOW

Rev. A | Page 5 of 24

AD5170

ABSOLUTE MAXIMUM RATINGS

TA = 25°C, unless otherwise noted.

Table 4.

Parameter Value

VDD to GND –0.3 V to +7 V
VA, VB, VW to GND VDD
Terminal Current, Ax–Bx, Ax–Wx, Bx–Wx1

Pulsed ±20 mA
Continuous ±5 mA

Digital Inputs and Output Voltage to GND 0 V to 7 V
Operating Temperature Range –40°C to +125°C
Maximum Junction Temperature (T

) 150°C

JMAX

Storage Temperature –65°C to +150°C
Lead Temperature (Soldering, 10 sec) 300°C
Thermal Resistance2 θJA: MSOP-10 230°C/W

1

Maximum terminal current is bound by the maximum current handling of

the switches, maximum power dissipation of the package, and maximum
applied voltage across any two of the A, B, and W terminals at a given
resistance.

2

Package power dissipation = (T

– TA)/θJA.

JMAX

Stresses above those listed under Absolute Maximum Ratings
may cause permanent damage to the device. This is a stress
rating only; functional operation of the device at these or any
other conditions above those indicated in the operational
section of this specification is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect
device reliability.

ESD CAUTION

ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily accumulate on
the human body and test equipment and can discharge without detection. Although this product features
proprietary ESD protection circuitry, permanent damage may occur on devices subjected to high energy
electrostatic discharges. Therefore, proper ESD precautions are recommended to avoid performance
degradation or loss of functionality.

Rev. A | Page 6 of 24

AD5170

TYPICAL PERFORMANCE CHARACTERISTICS

2.0

1.5

1.0

0.5

0

–0.5

–1.0

RHEOSTAT MODE INL (LSB)

–1.5

–2.0

VDD = 2.7V

Figure 2. R-INL vs. Code vs. Supply Voltages

0.5

0.4

0.3

0.2

0.1

0

–0.1

–0.2

RHEOSTAT MODE DNL (LSB)

–0.3

–0.4

–0.5

Figure 3. R-DNL vs. Code vs. Supply Voltages

0.5

0.4

0.3

0.2

0.1

0

–0.1

–0.2

–0.3

POTENTIOMETER MODE INL (LSB)

–0.4

–0.5

Figure 4. INL vs. Code vs. Temperature

VDD = 5.5V

1289632 640 160 192 224 256

CODE (DECIMAL)

VDD = 2.7V

VDD = 5.5V

1289632 640 160 192 224 256

CODE (DECIMAL)

VDD = 5.5V
T

= –40°C, +25°C, +85°C, +125°C

A

VDD = 2.7V

= –40°C, +25°C, +85°C, +125°C

T

A

1289632 640 160 192 224 256

CODE (DECIMAL)

TA = 25°C
R

= 10kΩ

AB

TA = 25°C
R

= 10kΩ

AB

RAB = 10kΩ

04104-0-002

04104-0-003

04104-0-004

0.5

0.4

0.3

0.2

0.1

0

–0.1

–0.2

–0.3

POTENTIOMETER MODE DNL (LSB)

–0.4

–0.5

VDD = 2.7V; TA = –40°C, +25°C, +85°C, +125°C

1289632 640 160 192 224 256

CODE (DECIMAL)

RAB = 10kΩ

04104-0-005

Figure 5. DNL vs. Code vs. Temperature

1.0

0.8

0.6

0.4

0.2

0

–0.2

–0.4

–0.6

POTENTIOMETER MODE INL (LSB)

–0.8

–1.0

VDD = 2.7V

1289632 640 160 192 224 256

CODE (DECIMAL)

VDD = 5.5V

TA = 25°C
R

= 10kΩ

AB

04104-0-006

Figure 6. INL vs. Code vs. Supply Voltages

0.5

0.4

0.3

0.2

0.1

0

–0.1

–0.2

–0.3

POTENTIOMETER MODE DNL (LSB)

–0.4

–0.5

VDD = 2.7V

VDD = 5.5V

1289632 640 160 192 224 256

CODE (DECIMAL)

TA = 25°C
R

= 10kΩ

AB

04104-0-007

Figure 7. DNL vs. Code vs. Supply Voltages

Rev. A | Page 7 of 24

AD5170

2.0

VDD = 2.7V

1.5
TA = –40°C, +25°C, +85°C, +125°C

1.0

0.5

RAB = 10kΩ

4.50
RAB = 10kΩ

3.75

3.00

0

–0.5

–1.0

RHEOSTAT MODE INL (LSB)

–1.5

–2.0

Figure 8. R-INL vs. Code vs. Temperature

0.5

0.4

0.3

0.2

VDD = 2.7V, 5.5V; TA = –40°C, +25°C, +85°C, +125°C

0.1

0

–0.1

–0.2

RHEOSTAT MODE DNL (LSB)

–0.3

–0.4

–0.5

Figure 9. R-DNL vs. Code vs. Temperature

2.0

1.5

1.0

0.5

0

–0.5

–1.0

FSE, FULL-SCALE ERROR (LSB)

–1.5

VDD = 2.7V, VA = 2.7V

VDD = 5.5V
T

= –40°C, +25°C, +85°C, +125°C

A

1289632 640 160 192 224 256

CODE (DECIMAL)

1289632 640 160 192 224 256

CODE (DECIMAL)

VDD = 5.5V, VA = 5.0V

RAB = 10kΩ

RAB = 10kΩ

04104-0-008

04104-0-009

2.25

1.50

ZSE, ZERO-SCALE ERROR (LSB)

0.75

VDD = 2.7V, VA = 2.7V

VDD = 5.5V, VA = 5.0V

0

–40 –25 –10 5 20 35 50 65 80 95 110 125

TEMPERATURE (°C)

Figure 11. Zero-Scale Error vs. Temperature

10

A)

µ

1

, SUPPLY CURRENT (

DD

I

0.1
–40 –7 26 59 92 125

VDD = 5V

VDD = 3V

TEMPERATURE (°C)

Figure 12. Supply Current vs. Temperature

120

100

80

60

40

20

RHEOSTAT MODE TEMPCO (ppm/°C)

0

VDD = 2.7V
T

= –40°C TO +85°C, –40°C TO +125°C

A

VDD = 5.5V
T

= –40°C TO +85°C, –40°C TO +125°C

A

RAB = 10kΩ

04104-0-011

04104-0-012

–2.0

–40 –25 –10 5 20 35 50 65 80 95 110 125

TEMPERATURE (°C)

Figure 10. Full-Scale Error vs. Temperature

04104-0-010

Rev. A | Page 8 of 24

–20

CODE (DECIMAL)

Figure 13. Rheostat Mode Tempco ∆R

1289632 640 160 192 224 256

/∆T vs. Code

WB

04104-0-013