AD AD5173BRM10

256-Position One-Time Programmable
Dual-Channel I2C Digital Potentiometers
AD5172/AD5173
FUNCTIONAL BLOCK DIAGRAMS
FEATURES
2-channel, 256-position
OTP (one-time programmable) set-and-forget resistance
setting, low cost alternative to EEMEM
Unlimited adjustments prior to OTP 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: tS = 5 µs typ in power-up
Full read/write of wiper register
Power-on preset to midscale
Extra package address decode pins AD0 and AD1 (AD5173)
Single supply 2.7 V to 5.5 V
Low temperature coefficient: 35 ppm/°C
Low power, IDD = 6 µA max
Wide operating temperature: –40°C to +125°C
Evaluation board and software are available
Software replaces µC in factory programming applications
A1
W1
B1
FUSE
LINKS
VDD
1
GND
A2
RDAC
REGISTER 1
W2
B2
2
RDAC
REGISTER 2
04103-0-001
/8
SDA
SERIAL INPUT
REGISTER
SCL
Figure 1. AD5172
W1
B1
W2
B2
APPLICATIONS
FUSE
LINKS
VDD
1
GND
AD0
AD1
SDA
SCL
GENERAL OVERVIEW
RDAC
REGISTER 2
RDAC
REGISTER 1
ADDRESS
DECODE
2
/8
SERIAL INPUT
REGISTER
04103-0-002
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
Figure 2. AD5173
The AD5172/AD5173 are dual channel, 256-position, one-time
programmable (OTP) digital potentiometers1 that employ fuse
link technology to achieve memory retention of 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.
2
The AD5172/AD5173 are programmed using a 2-wire, I C
compatible digital interface. Unlimited adjustments are allowed
before permanently 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 AD5172/
AD5173 have 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 powerup conditions. This feature allows users to treat these digital
potentiometers as volatile potentiometers with a programmable
preset.
For applications that program the AD5172/AD5173 at the
factory, Analog Devices offers device programming software
running on Windows® NT®, 2000, and XP® operating systems.
This software effectively replaces any external I2C controllers,
thus enhancing the time-to-market of the user’s systems.
1
The terms digital potentiometer, VR, and RDAC are used interchangeably.
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: 781.329.4700
www.analog.com
Fax: 781.326.8703
© 2003 Analog Devices, Inc. All rights reserved.
AD5172/AD5173
TABLE OF CONTENTS
Electrical Characteristics—2.5 kΩ ................................................. 3
Terminal Voltage Operating Range.......................................... 14
Electrical Characteristics—10 kΩ, 50 kΩ, 100 kΩ Versions ....... 4
Power-Up Sequence ................................................................... 14
Timing Characteristics—2.5 kΩ, 10 kΩ, 50 kΩ, 100 kΩ Versions
............................................................................................................. 5
Power Supply Considerations................................................... 14
Absolute Maximum Ratings............................................................ 6
Typical Performance Characteristics ............................................. 7
Test Circuits..................................................................................... 11
Operation......................................................................................... 12
One-Time Programming (OTP) .............................................. 12
Programming the Variable Resistor and Voltage.................... 12
Programming the Potentiometer Divider ............................... 13
Layout Considerations............................................................... 15
Evaluation Software/Hardware..................................................... 16
Software Programming ............................................................. 16
I2C Interface .................................................................................... 18
I2C Compatible 2-Wire Serial Bus ........................................... 20
Pin Configuration and Function Descriptions........................... 22
Outline Dimensions ....................................................................... 23
Ordering Guide............................................................................... 24
ESD Protection ........................................................................... 14
REVISION HISTORY
Revision A
11/03—Data Sheet Changed from Rev. 0 to Rev. A
Change
Location
Changes to Electrical Characteristics—2.5 kΩ......................... 3
Rev. A | Page 2 of 24
AD5172/AD5173
ELECTRICAL CHARACTERISTICS—2.5 kΩ
Table 1. VDD = 5 V ± 10% or 3 V ± 10%; VA = +VDD; VB = 0 V; –40°C < TA < +125°C; unless otherwise noted
Parameter
Symbol
Conditions
DC CHARACTERISTICS—RHEOSTAT MODE
Resistor Differential Nonlinearity2
R-DNL
RWB, VA = No Connect
Resistor Integral Nonlinearity2
R-INL
RWB, VA = No Connect
Nominal Resistor Tolerance3
∆RAB
TA = 25°C
Resistance Temperature Coefficient
(∆RAB/RAB)/∆T VAB = VDD, Wiper = No Connect
RWB (Wiper Resistance)
RWB
Code = 0x00, VDD = 5 V
DC CHARACTERISTICS—POTENTIOMETER DIVIDER MODE (Specifications Apply to all VRs)
Differential Nonlinearity4
DNL
Integral Nonlinearity4
INL
(∆VW/VW)/∆T Code = 0x80
Voltage Divider Temperature
Coefficient
Full-Scale Error
VWFSE
Code = 0xFF
Zero-Scale Error
VWZSE
Code = 0x00
RESISTOR TERMINALS
Voltage Range5
VA, VB, VW
Capacitance6 A, B
CA, CB
f = 1 MHz, Measured to GND,
Code = 0x80
Capacitance W
CW
f = 1 MHz, Measured to GND,
Code = 0x80
7
Shutdown Supply Current
IA_SD
VDD = 5.5 V
Common-Mode Leakage
ICM
VA = VB = VDD/2
DIGITAL INPUTS AND OUTPUTS
Input Logic High
VIH
VDD = 5 V
Input Logic Low
VIL
VDD = 5 V
Input Logic High
VIH
VDD = 3 V
Input Logic Low
VIL
VDD = 3 V
Input Current
IIL
VIN = 0 V or 5 V
Input Capacitance6
CIL
POWER SUPPLIES
Power Supply Range
VDD RANGE
OTP Supply Voltage
VDD_OTP
TA = 25°C
Supply Current
IDD
VIH = 5 V or VIL = 0 V
OTP Supply Current
IDD_OTP
VDD_OTP = 6 V, TA = 25°C
Power Dissipation8
PDISS
VIH = 5 V or VIL = 0 V, VDD = 5 V
Power Supply Sensitivity
PSS
VDD = 5 V ± 10%, Code = Midscale
9
DYNAMIC CHARACTERISTICS
Bandwidth –3 dB
BW_2.5K
Code = 0x80
Total Harmonic Distortion
THDW
VA = 1 V rms, VB = 0 V, f = 1 kHz
VW Settling Time
tS
VA = 5 V, VB = 0 V, ±1 LSB Error Band
Resistor Noise Voltage Density
eN_WB
RWB = 1.25 kΩ, RS = 0
1
Min
Typ1
Max
Unit
–2
–6
–20
±0.1
±0.75
+2
+6
+55
LSB
LSB
%
ppm/°C
Ω
35
160
200
–1.5
–2
±0.1
±0.6
15
+1.5
+2
LSB
LSB
ppm/°C
–10
0
–2.5
2
0
10
LSB
LSB
VDD
45
V
pF
60
pF
GND
0.01
1
1
2.4
0.8
2.1
0.6
±1
5
2.7
6
3.5
5.5
6.5
6
±0.02
30
±0.08
100
4.8
0.1
1
3.2
µA
nA
V
V
V
V
µA
pF
V
V
µA
mA
µW
%/%
MHz
%
µs
nV/√Hz
Typical specifications represent average readings at 25°C and VDD = 5 V.
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
PDISS is calculated from (IDD × VDD). CMOS logic level inputs result in minimum power dissipation.
9
All dynamic characteristics use VDD = 5 V.
2
Rev. A | Page 3 of 24
AD5172/AD5173
ELECTRICAL CHARACTERISTICS—10 kΩ, 50 kΩ, 100 kΩ VERSIONS
Table 2. VDD = 5 V ± 10% or 3 V ± 10%; VA = VDD; VB = 0 V; –40°C < TA < +125°C; unless otherwise noted
Parameter
Symbol
Conditions
DC CHARACTERISTICS—RHEOSTAT MODE
Resistor Differential Nonlinearity2
R-DNL
RWB, VA = No Connect
Resistor Integral Nonlinearity2
R-INL
RWB, VA = No Connect
Nominal Resistor Tolerance3
∆RAB
TA = 25°C
Resistance Temperature Coefficient
(∆RAB/RAB)/∆T VAB = VDD, Wiper = No Connect
RWB (Wiper Resistance)
RWB
Code = 0x00, VDD = 5 V
DC CHARACTERISTICS—POTENTIOMETER DIVIDER MODE (Specifications Apply to all VRs)
Differential Nonlinearity4
DNL
Integral Nonlinearity4
INL
Voltage Divider Temperature Coefficient
(∆VW/VW)/∆T
Code = 0x80
Full-Scale Error
VWFSE
Code = 0xFF
Zero-Scale Error
VWZSE
Code = 0x00
RESISTOR TERMINALS
Voltage Range5
VA, VB, VW
Capacitance6 A, B
CA, CB
f = 1 MHz, Measured to GND, Code = 0x80
Capacitance6 W
CW
f = 1 MHz, Measured to GND, Code = 0x80
Shutdown Supply Current7
IA_SD
VDD = 5.5 V
Common-Mode Leakage
ICM
VA = VB = VDD/2
DIGITAL INPUTS AND OUTPUTS
Input Logic High
VIH
VDD = 5 V
Input Logic Low
VIL
VDD = 5 V
Input Logic High
VIH
VDD = 3 V
Input Logic Low
VIL
VDD = 3 V
Input Current
IIL
VIN = 0 V or 5 V
Input Capacitance6
CIL
POWER SUPPLIES
Power Supply Range
VDD RANGE
OTP Supply Voltage8
VDD_OTP
Supply Current
IDD
VIH = 5 V or VIL = 0 V
OTP Supply Current9
IDD_OTP
Power Dissipation10
PDISS
VIH = 5 V or VIL = 0 V, VDD = 5 V
Power Supply Sensitivity
PSS
VDD = +5 V ± 10%, Code = Midscale
DYNAMIC CHARACTERISTICS11
Bandwidth –3 dB
BW
RAB = 10 kΩ, Code = 0x80
RAB = 50 kΩ, Code = 0x80
RAB = 100 kΩ, Code = 0x80
Total Harmonic Distortion
THDW
VA =1 V rms, VB = 0 V, f = 1 kHz, RAB = 10 kΩ
VW Settling Time (10 kΩ/50 kΩ/100 kΩ)
tS
VA = 5 V, VB = 0 V, ±1 LSB Error Band
Resistor Noise Voltage Density
eN_WB
RWB = 5 kΩ, RS = 0
1
Min
Typ1
Max
Unit
–1
–2.5
–20
±0.1
±0.25
+1
+2.5
+20
LSB
LSB
%
ppm/°C
Ω
35
160
–1
–1
–2.5
0
±0.1
±0.3
15
–1
1
GND
200
+1
+1
0
2.5
VDD
45
60
0.01
1
1
2.4
0.8
2.1
0.6
±1
5
2.7
6
3.5
5.5
6.5
6
±0.02
30
±0.08
100
600
100
40
0.1
2
9
LSB
LSB
ppm/°C
LSB
LSB
V
pF
pF
µA
nA
V
V
V
V
µA
pF
V
V
µA
mA
µW
%/%
kHz
kHz
kHz
%
µs
nV/√Hz
Typical specifications represent average readings at 25°C and VDD = 5 V.
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
PDISS is calculated from (IDD × VDD). CMOS logic level inputs result in minimum power dissipation.
11
All dynamic characteristics use VDD = 5 V.
2
Rev. A | Page 4 of 24
AD5172/AD5173
TIMING CHARACTERISTICS—2.5 kΩ, 10 kΩ, 50 kΩ, 100 kΩ VERSIONS
Table 3. VDD = 5 V ± 10% or 3V ± 10%; VA = VDD; VB = 0 V; –40°C < TA < +125°C; unless otherwise noted
Parameter
Symbol
Conditions
I2C INTERFACE TIMING CHARACTERISTICS1 (Specifications Apply to All Parts)
SCL Clock Frequency
fSCL
tBUF Bus Free Time between STOP and START
t1
tHD;STA Hold Time (Repeated START)
t2
After this period, the first clock pulse is
generated.
tLOW Low Period of SCL Clock
t3
tHIGH High Period of SCL Clock
t4
tSU;STA Setup Time for Repeated START Condition
t5
tHD;DAT Data Hold Time2
t6
tSU;DAT Data Setup Time
t7
tF Fall Time of Both SDA and SCL Signals
t8
tR Rise Time of Both SDA and SCL Signals
t9
tSU;STO Setup Time for STOP Condition
t10
1
2
See timing diagrams for locations of measured values.
The maximum tHD;DAT has only to be met if the device does not stretch the LOW period (tLOW) of the SCL signal.
Rev. A | Page 5 of 24
Min
Typ
Max
Unit
400
kHz
µs
µs
1.3
0.6
1.3
0.6
0.6
0.9
100
300
300
0.6
µs
µs
µs
µs
ns
ns
ns
µs
AD5172/AD5173
ABSOLUTE MAXIMUM RATINGS
Table 4. TA = 25°C, unless otherwise noted
Parameter
VDD to GND
VA, VB, VW to GND
Terminal Current, Ax–Bx, Ax–Wx, Bx–Wx1
Pulsed
Continuous
Digital Inputs and Output Voltage to GND
Operating Temperature Range
Maximum Junction Temperature (TJMAX)
Storage Temperature
Lead Temperature (Soldering, 10 sec)
Thermal Resistance2 θJA: MSOP-10
Value
–0.3 V to +7 V
VDD
±20 mA
±5 mA
0 V to 7 V
–40°C to +125°C
150°C
–65°C to +150°C
300°C
230°C/W
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.
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 = (TJMAX – TA)/θJA.
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
AD5172/AD5173
TYPICAL PERFORMANCE CHARACTERISTICS
2.0
0.5
TA = 25°C
RAB = 10kΩ
1.0
VDD = 2.7V
0.5
0
VDD = 5.5V
–0.5
RAB = 10kΩ
0.4
POTENTIOMETER MODE DNL (LSB)
–1.0
–1.5
0.3
0.2
0.1
VDD = 2.7V; TA = –40°C, +25°C, +85°C, +125°C
0
–0.1
–0.2
–0.3
32
64
96
128
160
192
224
256
CODE (DECIMAL)
–0.5
04103-0-003
0
0
32
128
160
192
224
256
Figure 6. DNL vs. Code vs. Temperature
0.5
1.0
TA = 25°C
RAB = 10kΩ
0.3
0.2
VDD = 2.7V
0.1
0
–0.1
–0.2
VDD = 5.5V
–0.3
TA = 25°C
RAB = 10kΩ
0.8
POTENTIOMETER MODE INL (LSB)
0.4
–0.4
0.6
0.4
VDD = 5.5V
0.2
0
VDD = 2.7V
–0.2
–0.4
–0.6
–0.8
0
32
64
96
128
160
192
224
256
CODE (DECIMAL)
–1.0
04103-0-004
–0.5
0
32
64
96
128
160
192
224
256
CODE (DECIMAL)
Figure 4. R-DNL vs. Code vs. Supply Voltages
04103-0-007
RHEOSTAT MODE DNL (LSB)
96
CODE (DECIMAL)
Figure 3. R-INL vs. Code vs. Supply Voltages
Figure 7. INL vs. Code vs. Supply Voltages
0.5
0.5
RAB = 10kΩ
0.3
VDD = 5.5V
TA = –40°C, +25°C, +85°C, +125°C
0.2
0.1
0
–0.1
VDD = 2.7V
TA = –40°C, +25°C, +85°C, +125°C
–0.2
TA = 25°C
RAB = 10kΩ
0.4
POTENTIOMETER MODE DNL (LSB)
0.4
–0.3
–0.4
0.3
0.2
0.1
VDD = 2.7V
0
–0.1
VDD = 5.5V
–0.2
–0.3
–0.4
–0.5
0
32
64
96
128
160
192
CODE (DECIMAL)
224
256
04103-0-005
POTENTIOMETER MODE INL (LSB)
64
04103-0-006
–0.4
–2.0
Figure 5. INL vs. Code vs. Temperature
–0.5
0
32
64
96
128
160
192
224
CODE (DECIMAL)
Figure 8. DNL vs. Code vs. Supply Voltages
Rev. A | Page 7 of 24
256
04103-0-008
RHEOSTAT MODE INL (LSB)
1.5
AD5172/AD5173
4.50
2.0
RAB = 10kΩ
RAB = 10kΩ
1.0
0.5
0
VDD = 5.5V
TA = –40°C, +25°C, +85°C, +125°C
–0.5
–1.0
–1.5
0
32
64
96
128
160
192
224
256
CODE (DECIMAL)
3.00
2.25
VDD = 2.7V, VA = 2.7V
1.50
VDD = 5.5V, VA = 5.0V
0.75
0
–40
04103-0-009
–2.0
3.75
–10
5
20
35
50
65
80
95
110
125
TEMPERATURE (°C)
Figure 9. R-INL vs. Code vs. Temperature
Figure 12. Zero-Scale Error vs. Temperature
0.5
10
RAB = 10kΩ
0.4
0.3
0.2
IDD, SUPPLY CURRENT (µA)
RHEOSTAT MODE DNL (LSB)
–25
04103-0-012
VDD = 2.7V
TA = –40°C, +25°C, +85°C, +125°C
ZSE, ZERO-SCALE ERROR (LSB)
RHEOSTAT MODE INL (LSB)
1.5
VDD = 2.7V, 5.5V; TA = –40°C, +25°C, +85°C, +125°C
0.1
0
–0.1
–0.2
VDD = 5V
1
VDD = 3V
–0.3
32
64
96
128
160
192
224
256
CODE (DECIMAL)
0.1
–40
–7
26
59
92
Figure 10. R-DNL vs. Code vs. Temperature
Figure 13. Supply Current vs. Temperature
120
2.0
RAB = 10kΩ
RAB = 10kΩ
RHEOSTAT MODE TEMPCO (ppm/°C)
1.0
0.5
0
VDD = 5.5V, VA = 5.0V
–0.5
–1.0
VDD = 2.7V, VA = 2.7V
–1.5
–25
–10
5
20
35
50
65
80
95
TEMPERATURE (°C)
110
125
04103-0-011
FSE, FULL-SCALE ERROR (LSB)
1.5
–2.0
–40
125
TEMPERATURE (°C)
100
80
60
VDD = 2.7V
TA = –40°C TO +85°C, –40°C TO +125°C
40
VDD = 5.5V
TA = –40°C TO +85°C, –40°C TO +125°C
20
0
–20
0
32
64
96
128
160
192
224
CODE (DECIMAL)
Figure 14. Rheostat Mode Tempco ∆RWB/∆T vs. Code
Figure 11. Full-Scale Error vs. Temperature
Rev. A | Page 8 of 24
256
04103-0-014
0
04103-0-010
–0.5
04103-0-013
–0.4
AD5172/AD5173
0
RAB = 10kΩ
0x80
–6
40
0x40
–12
30
0x20
–18
VDD = 2.7V
TA = –40°C TO +85°C, –40°C TO +125°C
GAIN (dB)
20
10
0
0x10
–24
0x08
–30
0x04
–36
0x02
–42
–10
0x01
VDD = 5.5V
TA = –40°C TO +85°C, –40°C TO +125°C
–48
–20
0
32
64
96
128
160
192
224
256
CODE (DECIMAL)
–60
1k
10k
100k
1M
FREQUENCY (Hz)
Figure 15. AD5172 Potentiometer Mode Tempco ∆VWB/∆T vs. Code
04103-0-050
–54
–30
04103-0-047
POTENTIOMETER MODE TEMPCO (ppm/°C)
50
Figure 18. Gain vs. Frequency vs. Code, RAB = 50 kΩ
0
0
0x80
–6
–12
0x80
–6
0x40
0x40
–12
0x20
–18
0x20
–18
–24
–30
GAIN (dB)
0x08
0x04
–36
0x02 0x01
–42
0x10
–24
0x08
–30
0x04
–36
0x02
–42
–48
–54
–54
–60
10k
100k
1M
10M
FREQUENCY (Hz)
–60
1k
100k
1M
FREQUENCY (Hz)
Figure 16. Gain vs. Frequency vs. Code, RAB = 2.5 kΩ
Figure 19. Gain vs. Frequency vs. Code, RAB = 100 kΩ
0
0
0x80
–12
0x40
–18
0x20
–6
–12
GAIN (dB)
0x10
–24
0x08
–30
0x04
–36
0x02
0x01
–42
10kΩ
570kHz
2.5kΩ
2.2MHz
–30
–36
–42
–54
–60
100k
FREQUENCY (Hz)
1M
04103-0-049
–48
–54
10k
50kΩ
120kHz
–24
–48
1k
100kΩ
60kHz
–18
Figure 17. Gain vs. Frequency vs. Code, RAB = 10 kΩ
–60
1k
10k
100k
1M
FREQUENCY (Hz)
Figure 20. –3 dB Bandwidth @ Code = 0x80
Rev. A | Page 9 of 24
10M
04103-0-052
–6
GAIN (dB)
10k
04103-0-051
0x01
–48
04103-0-048
GAIN (dB)
0x10
AD5172/AD5173
10
1
VDD = 5.5V
VW2
0.1
VDD = 2.7V
0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
DIGITAL INPUT VOLTAGE (V)
4.0
4.5
5.0
04103-0-057
0.01
04103-0-056
VW1
Figure 24. Analog Crosstalk
Figure 21. IDD vs. Input Voltage
VW
VW
04103-0-053
04103-0-058
SCL
Figure 25. Midscale Glitch, Code 0x80 to 0x7F
Figure 22. Digital Feedthrough
VW
VW2
04103-0-055
SCL
VW1
04103-0-054
IDD, SUPPLY CURRENT (mA)
TA = 25°C
Figure 26. Large Signal Settling Time
Figure 23. Digital Crosstalk
Rev. A | Page 10 of 24
AD5172/AD5173
TEST CIRCUITS
Figure 27 to Figure 34 illustrate the test circuits that define the
test conditions used in the product specification tables.
A
DUT
A
V+ = VDD
1LSB = V+/2N
DUT
W
V+
+15V
W
VIN
AD8610
OFFSET
GND
B
2.5V
Figure 27. Test Circuit for Potentiometer Divider Nonlinearity Error (INL, DNL)
–15V
Figure 31. Test Circuit for Gain vs. Frequency
NO CONNECT
DUT
RSW =
DUT
IW
W
W
B
GND TO VDD
Figure 32. Test Circuit for Incremental On Resistance
NC
DUT
W
VW
I W = VDD /R NOMINAL
DUT
VDD
B
VMS1
RW = [VMS1 – VMS2]/ I W
A
04103-0-017
A
0.1V
B
Figure 28. Test Circuit for Resistor Position Nonlinearity Error
(Rheostat Operation; R-INL, R-DNL)
VMS2
CODE = 0x00
ISW
04103-0-016
VMS
0.1V
ISW
W
GND B
ICM
VCM
04103-0-021
A
VOUT
04103-0-020
VMS
04103-0-019
04103-0-015
B
NC
Figure 29. Test Circuit for Wiper Resistance
Figure 33. Test Circuit for Common-Mode Leakage Current
VA
A
V+
B
W
PSS (%/%) =
VMS
∆V MS%
∆V
A1
RDAC1
(∆V MS
)
DD
∆V DD%
N/C
A2
VDD
RDAC2
W1
W2
VIN
B1
Figure 30. Test Circuit for Power Supply Sensitivity (PSS, PSSR)
VSS
CTA = 20 log[VOUT/VIN]
VOUT
B2
04103-0-022
VDD
V+ = VDD 10%
PSRR (dB) = 20 LOG
04103-0-018
DUT
Figure 34. Test Circuit for Analog Crosstalk
Rev. A | Page 11 of 24
AD5172/AD5173
OPERATION
A
SCL
I2C
SDA
INTERFACE
DECODER
MUX
DAC
REG.
W
B
COMPARATOR
FUSES
EN
FUSE
REG.
04103-0-026
ONE-TIME
PROGRAM/TEST
CONTROL BLOCK
Figure 35. Detailed Functional Block Diagram
A
A
A
W
An internal power-on preset places the wiper at midscale
during power-on. If the OTP function has been activated, the
device powers up at the user-defined permanent setting.
ONE-TIME PROGRAMMING (OTP)
Prior to OTP activation, the AD5172/AD5173 presets to midscale during initial power-on. After the wiper is set at the
desired position, the resistance can be permanently set by
programming the T bit high along with the proper coding (see
Table 5 and Table 6). Note that fuse link technology requires 6 V
to blow the internal fuses to achieve a given setting. The user is
allowed only one attempt at blowing the fuses. Once programming is completed, the power supply voltage must be reduced to
the normal operating range of 2.7 V to 5.5 V.
W
B
B
W
04103-0-027
The AD5172/AD5173 is a 256-position, digitally controlled
variable resistor (VR) that employs fuse link technology to
achieve memory retention of resistance setting.
B
Figure 36. Rheostat Mode Configuration
Assuming a 10 kΩ part is used, the wiper’s first connection
starts at the B terminal for data 0x00. Because there is a 50 Ω
wiper contact resistance, such a connection yields a minimum
of 100 Ω (2 × 50 Ω) resistance between terminals W and B. The
second connection is the first tap point, which corresponds to
139 Ω (RWB = RAB/256 + 2 × RW = 39 Ω + 2 × 50 Ω) for data
0x01. The third connection is the next tap point, representing
178 Ω (2 × 39 Ω + 2 × 50 Ω) for data 0x02, and so on. Each LSB
data value increase moves the wiper up the resistor ladder until
the last tap point is reached at 10,100 Ω (RAB + 2 × RW).
The device control circuit has two validation bits, E1 and E0,
that can be read back to check the programming status (see
Table 7). Users should always read back the validation bits to
ensure that the fuses are properly blown. After the fuses have
been blown, all fuse latches are enabled upon subsequent
power-on; therefore, the output corresponds to the stored
setting. Figure 35 shows a detailed functional block diagram.
A
RS
D7
D6
D5
D4
D3
D2
D1
D0
RS
RS
W
PROGRAMMING THE VARIABLE RESISTOR AND
VOLTAGE
Rheostat Operation
RDAC
Rev. A | Page 12 of 24
LATCH
AND
DECODER
RS
B
04103-0-028
The nominal resistance of the RDAC between terminals A and
B is available in 2.5 kΩ, 10 kΩ, 50 kΩ, and 100 kΩ. The nominal
resistance (RAB) of the VR has 256 contact points accessed by
the wiper terminal, plus the B terminal contact. The 8-bit data
in the RDAC latch is decoded to select one of the 256 possible
settings.
Figure 37. AD5172/AD5173 Equivalent RDAC Circuit
AD5172/AD5173
The general equation that determines the digitally programmed
output resistance between W and B is
RWB(D) =
D
× RAB + 2 × RW
128
(1)
where D is the decimal equivalent of the binary code loaded in
the 8-bit RDAC register, RAB is the end-to-end resistance, and
RW is the wiper resistance contributed by the on resistance of
the internal switch.
In summary, if RAB = 10 kΩ and the A terminal is opencircuited, the output resistance RWB is set for the RDAC latch
codes, as shown in Table 5.
Typical device-to-device matching is process lot dependent and
may vary by up to ±30%. Because the resistance element is processed using thin film technology, the change in RAB with
temperature has a very low 35 ppm/°C temperature coefficient.
PROGRAMMING THE POTENTIOMETER DIVIDER
Voltage Output Operation
The digital potentiometer easily generates a voltage divider at
wiper-to-B and wiper-to-A proportional to the input voltage at
A-to-B. Unlike the polarity of VDD to GND, which must be positive, voltage across A-B, W-A, and W-B can be at either polarity.
VI
A
D (Dec.)
255
128
1
0
RWB (Ω)
9,961
5,060
139
100
Note that in the zero-scale condition, a finite wiper resistance of
100 Ω is present. Care should be taken to limit the current flow
between W and B in this state to a maximum pulse current of
no more than 20 mA. Otherwise, degradation or possible
destruction of the internal switch contact can occur.
Similar to the mechanical potentiometer, the resistance of the
RDAC between the wiper W and terminal A also produces a
digitally controlled complementary resistance, RWA. When these
terminals are used, the B terminal can be opened. Setting the
resistance value for RWA starts at a maximum value of resistance
and decreases as the data loaded in the latch increases in value.
The general equation for this operation is
RWA(D) =
256 – D
× RAB + 2 × RW
128
Table 6. Codes and Corresponding RWA Resistance
RWA (Ω)
139
5,060
9,961
10,060
Output State
Full-Scale
Midscale
1 LSB
Zero-Scale
VO
B
Figure 38. Potentiometer Mode Configuration
If ignoring the effect of the wiper resistance for approximation,
connecting the A terminal to 5 V and the B terminal to ground
produces an output voltage at the wiper-to-B starting at 0 V up
to 1 LSB less than 5 V. Each LSB of voltage is equal to the
voltage applied across terminal AB divided by the 256 positions
of the potentiometer divider. The general equation defining the
output voltage at VW with respect to ground for any valid input
voltage applied to terminals A and B is
VW (D ) =
256 − D
D
VA +
VB
256
256
(3)
For a more accurate calculation, which includes the effect of
wiper resistance, VW can be found as
(2)
For RAB = 10 kΩ and the B terminal open-circuited, the
following output resistance RWA is set for the RDAC latch codes,
as shown in Table 6.
D (Dec.)
255
128
1
0
W
Output State
Full-Scale (RAB – 1 LSB + RW)
Midscale
1 LSB
Zero-Scale (Wiper Contact Resistance)
04103-0-029
Table 5. Codes and Corresponding RWB Resistance
VW (D) =
R (D)
RWB (D)
VB
V A + WA
R AB
R AB
(4)
Operation of the digital potentiometer in the divider mode
results in a more accurate operation over temperature. Unlike
the rheostat mode, the output voltage is dependent mainly on
the ratio of the internal resistors RWA and RWB and not the absolute values. Thus, the temperature drift reduces to 15 ppm/°C.
Rev. A | Page 13 of 24
AD5172/AD5173
ESD PROTECTION
POWER SUPPLY CONSIDERATIONS
All digital inputs—SDA, SCL, AD0, and AD1— are protected
with a series input resistor and parallel Zener ESD structures, as
shown in Figure 39 and Figure 40.
To minimize the package pin count, both the one-time programming and normal operating voltage supplies are applied to
the same VDD terminal of the AD5172/AD5173. The AD5172/
AD5173 employ fuse link technology that requires 6 V to blow
the internal fuses to achieve a given setting. The user is allowed
only one attempt at blowing the fuses. Once programming is
completed, power supply voltage must be reduced to the normal
2.7 V to 5.5 V operating range. Such dual voltage requirements
require isolation between the supplies. The fuse programming
supply (either an on-board regulator or rack-mount power supply) must be rated at 6 V and must be able to provide a 100 mA
transient current for 400 ms for successful one-time programming. Once programming is complete, the 6 V supply must be
removed to allow normal operation at 2.7 V to 5.5 V at regular
microamp current levels. Figure 42 shows the simplest implementation using a jumper. This approach saves one voltage
supply, but draws additional current and requires manual
configuration.
340Ω
GND
04103-0-030
LOGIC
Figure 39. ESD Protection of Digital Pins
GND
04103-0-031
A,B,W
Figure 40. ESD Protection of Resistor Terminals
TERMINAL VOLTAGE OPERATING RANGE
The AD5172/AD5173 VDD to GND power supply defines the
boundary conditions for proper 3-terminal digital potentiometer operation. Supply signals present on terminals A, B, and W
that exceed VDD or GND are clamped by the internal forwardbiased diodes (see Figure 41).
CONNECT J1 HERE
FOR OTP
6V
R1
50kΩ
VDD
5V
R2
C1
1µF
C2
1nF
AD5172/
AD5173
250kΩ
CONNECT J1 HERE
AFTER OTP
04103-0-033
VDD
A
Figure 42. Power Supply Requirement
W
B
04103-0-032
GND
An alternate approach in 3.5 V to 5.5 V systems adds a signal
diode between the system supply and the OTP supply for
isolation, as shown in Figure 43.
Figure 41. Maximum Terminal Voltages Set by VDD and GND
6V
POWER-UP SEQUENCE
APPLY FOR OTP ONLY
D1
VDD
C1
1µF
C2
1nF
AD5172/
AD5173
04103-0-034
Because the ESD protection diodes limit the voltage compliance
at terminals A, B, and W (see Figure 41), it is important to
power VDD/GND before applying any voltage to terminals A, B,
and W. Otherwise, the diode will be forward biased such that
VDD is powered unintentionally and may affect the rest of the
user’s circuit. The ideal power-up sequence is GND, VDD, the
digital inputs, and then VA/VB/VW. The relative order of
powering VA, VB, VW, and the digital inputs is not important as
long as they are powered after VDD/GND.
3.5V–5.5V
Figure 43. Isolate 6 V OTP Supply from 3.5 V to 5.5 V Normal Operating
Supply. The 6 V supply must be removed once OTP is completed.
Rev. A | Page 14 of 24
AD5172/AD5173
R1
10kΩ
VDD
2.7V
P1
P2
C1
1µF
C2
1nF
AD5172/
AD5173
04103-0-035
P1=P2=FDV302P, NDS0610
Figure 44. Isolate 6 V OTP Supply from 2.7 V Normal Operating Supply.
The 6 V supply must be removed once OTP is completed.
For users who operate their systems at 2.7 V, use of the
bidirectional low threshold P-Ch MOSFETs is recommended
for the supply’s isolation. As shown in Figure 44, this assumes
that the 2.7 V system voltage is applied first, and that the P1 and
P2 gates are pulled to ground, thus turning on P1 and
subsequently P2. As a result, VDD of the AD5172/AD5173
approaches 2.7 V. When the AD5172/AD5173 setting is found,
the factory tester applies the 6 V to VDD; the 6 V is also applied
to the gates of P1 and P2 to turn them off. The OTP command
is executed at this time to program the AD5172/AD5173; the
2.7 V source is therefore protected. Once the OTP is completed,
the tester withdraws the 6 V and the AD5172/AD5173’s setting
is fixed permanently.
Poor PCB layout introduces parasitics that may affect the fuse
programming. Therefore, it is recommended to add a 1 µF
tantalum capacitor in parallel with a 1 nF ceramic capacitor as
close as possible to the VDD pin. These capacitors help ensure
OTP programming success by providing proper current densities. This combination of capacitor values provides both a fast
response for high frequency transients and a larger supply of
current for extended spikes. Typically, C1 minimizes any
transient disturbances and low frequency ripple, while C2
reduces high frequency noise.
LAYOUT CONSIDERATIONS
It is a good practice to employ compact, minimum lead length
layout design. The leads to the inputs should be as direct as
possible with a minimum conductor length. Ground paths
should have low resistance and low inductance.
Note that the digital ground should also be joined remotely to
the analog ground at one point to minimize the ground bounce.
AD5172/AD5173 achieves the OTP function through blowing
internal fuses. Users should always apply the 6 V one-time
program voltage requirement at the first program command.
Failure to comply with this requirement may lead to the change
of fuse structures, rendering programming inoperable.
Rev. A | Page 15 of 24
VDD
C1
1µF
+
VDD
C2
1nF
AD5172
GND
04103-0-036
APPLY FOR OTP ONLY
6V
Figure 45. Power Supply Bypassing
AD5172/AD5173
EVALUATION SOFTWARE/HARDWARE
Figure 46. AD5172/AD5173 Computer Software Interface
There are two ways of controlling the AD5172/AD5173. Users
can either program the devices with computer software or with
external I2C controllers.
SOFTWARE PROGRAMMING
Due to the advantages of the one-time programmable feature,
users may consider programming the device in the factory
before shipping the final product to end-users. ADI offers a
device programming software that can be implemented in the
factory on PCs running Windows 95 or later. As a result,
external controllers are not required, which significantly
reduces development time. The program is an executable file
that does not require any programming languages or user
programming skills. It is easy to set up and to use. Figure 46
shows the software interface. The software can be downloaded
from www.analog.com.
The AD5172/AD5173 starts at midscale after power-up prior to
OTP programming. To increment or decrement the resistance,
the user may simply move the scrollbars on the left. To write
any specific value, the user should use the bit pattern in the
upper screen and press the Run button. The format of writing
data to the device is shown in Table 7. Once the desired setting
is found, the user may press the Program Permament button to
blow the internal fuse links.
To read the validation bits and data out from the device, the
user simply presses the Read button. The format of the read bits
is shown in Table 8.
To apply the device programming software in the factory, users
must modify a parallel port cable and configure Pins 2, 3, 15,
and 25 for SDA_write, SCL, SDA_read, and DGND, respectively,
for the control signals (Figure 47). Users should also lay out the
PCB of the AD5172/AD5173 with SCL and SDA pads, as shown
in Figure 48, such that pogo pins can be inserted for factory
programming.
Rev. A | Page 16 of 24
AD5172/AD5173
AD5172
13
25
12
24
11
23
10
22
9
21
8
AD5173
B1
AD0
W2
GND
VDD
W1
B2
AD1
SDA
SCL
04103-0-038
W1
B2
A2
SDA
SCL
Figure 48. Recommended AD5172/AD5173 PCB Layout. The SCL and SDA
pads allow pogo pins to be inserted so that signals can be communicated
through the parallel port for programming (Figure 47).
R3
100Ω
R2 READ
100Ω
SCL
SDA
R1 WRITE
100Ω
04103-0-037
20
7
19
6
18
5
17
4
16
3
15
2
14
1
B1
A1
W2
GND
VDD
Figure 47. Parallel Port Connection. Pin 2 = SDA_write, Pin 3 = SCL,
Pin 15 = SDA_read, and Pin 25 = DGND.
Rev. A | Page 17 of 24
AD5172/AD5173
I2C INTERFACE
Table 7. Write Mode
AD5172
S
0
1
0 1 1 1
1
Slave Address Byte
W
A
A0 SD
T
0 OW X
Instruction Byte
X
X
A
D7 D6 D5 D4 D3 D2 D1 D0
Data Byte
A
P
1
0 1 1 AD1 AD0 W
Slave Address Byte
A
A0 SD
T
0 OW X
Instruction Byte
X
X
A
D7 D6 D5 D4 D3 D2 D1 D0
Data Byte
A
P
AD5173
S
0
Table 8. Read Mode
AD5172
S
0
1
0 1 1 1
1
Slave Address Byte
R
A
D7 D6 D5 D4 D3 D2 D1 D0
Instruction Byte
A
E1
E0
X
X X X
Data Byte
X
X
A
P
1
0 1 1 AD1 AD0 R
Slave Address Byte
A
D7 D6 D5 D4 D3 D2 D1 D0
Instruction Byte
A
E1
E0
X
X X X
Data Byte
X
X
A
P
AD5173
S
0
S = Start Condition
A = Acknowledge
OW = Overwrite the fuse setting and program the digital
potentiometer to a different setting. Note that upon power-up,
the digital potentiometer is preset to either midscale or fuse
setting, depending on whether not the fuse link has been blown.
AD0, AD1 = Package Pin Programmable Address Bits
D7, D6, D5, D4, D3, D2, D1, D0 = Data Bits.
X = Don’t Care
E1, E0 = OTP Validation Bits.
W = Write
0, 0 = Ready to Program.
R = Read
1, 0 = Fatal Error. Some fuses not blown. Do not retry. Discard
this unit.
P = Stop Condition
A0 = RDAC Subaddress Select Bit
SD = Shutdown connects wiper to B terminal and open circuits
the A terminal. It does not change contents of wiper register.
1, 1 = Programmed Successfully. No further adjustments
possible.
T = OTP Programming Bit. Logic 1 programs the wiper
permanently.
Rev. A | Page 18 of 24
AD5172/AD5173
t8
t6
t2
t9
SCL
t4
t3
t2
t7
t10
t5
t9
t8
04103-0-039
SDA
t1
P
S
S
P
Figure 49. I2C Interface Detailed Timing Diagram
9
1
1
9
1
9
SDA
0
1
0
1
1
1
1
R/W
A0
SD
T
0
OW
X
X
X
ACK BY
AD5172
START BY
MASTER
D7
D6
D5
D4
D3
D2
D1
D0
ACK BY
AD5172
ACK BY
AD5172
STOP BY
MASTER
FRAME 3
DATA BYTE
FRAME 2
INSTRUCTION BYTE
FRAME 1
SLAVE ADDRESS BYTE
04103-0-040
SCL
Figure 50. Writing to the RDAC Register—AD5172
1
9
1
9
1
9
SDA
0
1
0
1
1
AD1 AD0 R/W
A0
SD
T
0
OW
X
X
ACK BY
AD5173
START BY
MASTER
X
D7
D6
D5
D4
D3
D2
D1
D0
ACK BY
AD5173
ACK BY
AD5173
FRAME 2
INSTRUCTION BYTE
FRAME 1
SLAVE ADDRESS BYTE
04103-0-041
SCL
STOP BY
MASTER
FRAME 3
DATA BYTE
Figure 51. Writing to the RDAC Register—AD5173
1
9
1
9
1
9
SDA
0
1
0
1
1
1
1 R/W
D7
D6
D5
D4
D3
D2
D1
ACK BY
AD5172
START BY
MASTER
D0
E1
E0
X
X
X
X
X
X
NO ACK
BY MASTER
ACK BY
MASTER
FRAME 2
INSTRUCTION BYTE
FRAME 1
SLAVE ADDRESS BYTE
04103-0-042
SCL
STOP BY
MASTER
FRAME 3
DATA BYTE
Figure 52. Reading Data from a Previously Selected RDAC Register in Write Mode—AD5172
1
9
1
9
1
9
SDA
0
1
0
1
1
AD1 AD0 R/W
D7
D6
D5
D4
D3
D2
ACK BY
AD5173
START BY
MASTER
FRAME 1
SLAVE ADDRESS BYTE
D1
D0
E1
E0
X
X
X
FRAME 2
INSTRUCTION BYTE
FRAME 3
DATA BYTE
Figure 53. Reading Data from a Previously Selected RDAC Register in Write Mode—AD5173
Rev. A | Page 19 of 24
X
X
X
NO ACK
BY MASTER
ACK BY
MASTER
04103-0-043
SCL
STOP BY
MASTER
AD5172/AD5173
I2C COMPATIBLE 2-WIRE SERIAL BUS
The 2-wire I2C serial bus protocol operates as follows:
1.
The master initiates data transfer by establishing a START
condition, which is when a high-to-low transition on the
SDA line occurs while SCL is high (see Figure 50 and
Figure 51). The following byte is the slave address byte,
which consists of the slave address followed by an R/W bit
(this bit determines whether data is read from or written to
the slave device). The AD5172 has a fixed slave address
byte, whereas the AD5173 has two configurable address
bits, AD0 and AD1 (see Figure 50 and Figure 51).
After acknowledging the instruction byte, the last byte in
write mode is the data byte. Data is transmitted over the
serial bus in sequences of nine clock pulses (eight data bits
followed by an acknowledge bit). The transitions on the
SDA line must occur during the low period of SCL and
remain stable during the high period of SCL (see
Figure 49).
3.
The slave whose address corresponds to the transmitted
address responds by pulling the SDA line low during the
ninth clock pulse (this is termed the acknowledge bit). At
this stage, all other devices on the bus remain idle while the
selected device waits for data to be written to or read from
its serial register. If the R/W bit is high, the master reads
from the slave device. If the R/W bit is low, the master
writes to the slave device.
2.
Note that the channel of interest is the one that is
previously selected in the write mode. In the case where
users need to read the RDAC values of both channels, they
must program the first channel in the write mode and then
change to the read mode to read the first channel value.
After that, the user must change back to the write mode
with the second channel selected and read the second
channel value in the read mode. It is not necessary for users
to issue the Frame 3 data byte in the write mode for subsequent readback operation. Refer to Figure 52 and Figure 53
for the programming format.
In the write mode, the second byte is the instruction byte.
The first bit (MSB) of the instruction byte is the RDAC
subaddress select bit. A logic low selects channel 1; a logic
high selects channel 2.
The second MSB, SD, is a shutdown bit. A logic high causes
an open circuit at terminal A while shorting the wiper to
terminal B. This operation yields almost 0 Ω in rheostat
mode or 0 V in potentiometer mode. It is important to note
that the shutdown operation does not disturb the contents
of the register. When brought out of shutdown, the previous setting is applied to the RDAC. Also, during shutdown,
new settings can be programmed. When the part is
returned from shutdown, the corresponding VR setting is
applied to the RDAC.
Following the data byte, the validation byte contains two
validation bits, E0 and E1. These bits signify the status of
the one-time programming (see Figure 52 and Figure 53).
4.
The third MSB, T, is the OTP programming bit. A logic
high blows the poly fuses and programs the resistor setting
permanently.
The fourth MSB must always be at Logic 0.
The fifth MSB, OW, is an overwrite bit. When raised to a
logic high, OW allows the RDAC setting to be changed
even after the internal fuses have been blown. However,
once OW is returned to a logic zero, the position of the
RDAC returns to the setting prior to overwrite. Because
OW is not static, if the device is powered off and on, the
RDAC presets to midscale or to the setting at which the
fuses were blown, depending on whether or not the fuses
have been permanently set already.
The remainder of the bits in the instruction byte are don’t
cares (see Figure 50 and Figure 51).
In the read mode, the data byte follows immediately after
the acknowledgment of the slave address byte. Data is
transmitted over the serial bus in sequences of nine clock
pulses (a slight difference from the write mode, where there
are eight data bits followed by an acknowledge bit). Similarly, the transitions on the SDA line must occur during the
low period of SCL and remain stable during the high
period of SCL (see Figure 52 and Figure 53).
After all data bits have been read or written, a STOP
condition is established by the master. A STOP condition is
defined as a low-to-high transition on the SDA line while
SCL is high. In write mode, the master pulls the SDA line
high during the 10th clock pulse to establish a STOP
condition (see Figure 50 and Figure 51). In read mode, the
master issues a No Acknowledge for the ninth clock pulse
(i.e., the SDA line remains high). The master then brings
the SDA line low before the 10th clock pulse, which goes
high to establish a STOP condition (see Figure 52 and
Figure 53).
A repeated write function gives the user flexibility to update the
RDAC output a number of times after addressing and instructing the part only once. For example, after the RDAC has
acknowledged its slave address and instruction bytes in the
write mode, the RDAC output is updated on each successive
byte. If different instructions are needed, the write/read mode
has to start again with a new slave address, instruction, and data
byte. Similarly, a repeated read function of the RDAC is also
allowed.
Rev. A | Page 20 of 24
AD5172/AD5173
5V
Table 9. Validation Status
1
E0
0
0
1
Status
Ready for Programming.
Fatal Error. Some fuses not blown.
Do not retry. Discard this unit.
Successful. No further
programming is possible.
RP
SDA
MASTER
SCL
5V
SDA
SCL
5V
SDA
SCL
5V
SDA
SCL
SDA
SCL
AD1
AD1
AD1
AD1
Multiple Devices on One Bus(AD5173 Only)
AD0
AD0
AD0
AD0
Figure 54 shows four AD5173s on the same serial bus. Each has
a different slave address because the states of their AD0 and
AD1 pins are different. This allows each device on the bus to be
written to or read from independently. The master device
output bus line drivers are open-drain pull-downs in a fully I2C
compatible interface.
AD5173
AD5173
AD5173
AD5173
Rev. A | Page 21 of 24
Figure 54. Multiple AD5173s on One I2C Bus
04103-0-044
E1
0
1
RP
AD5172/AD5173
10
W1
B1 1
10
W1
A1 2
9
B2
AD0 2
9
B2
W2 3
AD5173
8
AD1
GND 4
TOP VIEW
7
SDA
6
SCL
W2 3
AD5172
8
A2
GND 4
TOP VIEW
7
SDA
6
SCL
VDD 5
04103-0-045
B1 1
VDD 5
Figure 55. AD5172 Pin Configuration
04103-0-046
PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
Figure 56. AD5173 Pin Configuration
Table 10. AD5172 Pin Function Descriptions
Table 11.AD5173 Pin Function Descriptions
Pin
1
2
3
4
5
6
7
8
9
10
Pin
1
2
Mnemonic
B1
AD0
3
4
5
6
7
8
W2
GND
VDD
SCL
SDA
AD1
9
10
B2
W1
Menmonic
B1
A1
W2
GND
VDD
SCL
SDA
A2
B2
W1
Description
B1 Terminal.
A1 Terminal.
W2 Terminal.
Digital Ground.
Positive Power Supply.
Serial Clock Input. Positive edge triggered.
Serial Data Input/Output.
A2 Terminal.
B2 Terminal.
W1 Terminal.
Rev. A | Page 22 of 24
Description
B1 Terminal.
Programmable Address Bit 0 for Multiple
Package Decoding.
W2 Terminal.
Digital Ground.
Positive Power Supply.
Serial Clock Input. Positive edge triggered.
Serial Data Input/Output.
Programmable Address Bit 1 for Multiple
Package Decoding.
B2 Terminal.
W1 Terminal.
AD5172/AD5173
OUTLINE DIMENSIONS
3.00 BSC
10
6
4.90 BSC
3.00 BSC
1
5
PIN 1
0.50 BSC
0.95
0.85
0.75
0.15
0.00
1.10 MAX
0.27
0.17
SEATING
PLANE
0.23
0.08
8°
0°
COPLANARITY
0.10
COMPLIANT TO JEDEC STANDARDS MO-187BA
Figure 57. 10-Lead Mini Small Outline Package [MSOP]
(RM-10)
Dimensions shown in millimeters
Rev. A | Page 23 of 24
0.80
0.60
0.40
AD5172/AD5173
ORDERING GUIDE
Model
AD5172BRM2.5
AD5172BRM2.5-RL7
AD5172BRM10
AD5172BRM10-RL7
AD5172BRM50
AD5172BRM50-RL7
AD5172BRM100
AD5172BRM100-RL7
AD5172EVAL1
AD5173BRM2.5
AD5173BRM2.5-RL7
AD5173BRM10
AD5173BRM10-RL7
AD5173BRM50
AD5173BRM50-RL7
AD5173BRM100
AD5173BRM100-RL7
AD5173EVAL1
1
RAB (kΩ)
2.5
2.5
10
10
50
50
100
100
Temperature Range
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
2.5
2.5
10
10
50
50
100
100
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
Package Description
MSOP-10
MSOP-10
MSOP-10
MSOP-10
MSOP-10
MSOP-10
MSOP-10
MSOP-10
Evaluation Board
MSOP-10
MSOP-10
MSOP-10
MSOP-10
MSOP-10
MSOP-10
MSOP-10
MSOP-10
Evaluation Board
Package Option
RM-10
RM-10
RM-10
RM-10
RM-10
RM-10
RM-10
RM-10
Branding
D0U
D0U
D0V
D0V
D10
D10
D11
D11
RM-10
RM-10
RM-10
RM-10
RM-10
RM-10
RM-10
RM-10
D1K
D1K
D1L
D1L
D1M
D1M
D1N
D1N
The evaluation board is shipped with the 10 kΩ RAB resistor option; however, the board is compatible with all available resistor value options.
Purchase of licensed I2C components of Analog Devices or one of its sublicensed Associated Companies conveys a license for the purchaser under the Philips I2C Patent
Rights to use these components in an I2C system, provided that the system conforms to the I2C Standard Specification as defined by Philips.
© 2003 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
C04103–0–11/03(A)
Rev. A | Page 24 of 24