Rev 1; 9/06
Addressable Digital Potentiometer
General Description
The DS1805 addressable digital potentiometer contains
a single 256-position digitally controlled potentiometer.
Device control is achieved through a 2-wire serial inter-
face. Device addressing is provided through three
address inputs that allow up to eight devices on a sin-
gle 2-wire bus. The exact wiper position of the poten-
tiometer can be written or read. The DS1805 is
available in 16-pin SO and 14-pin TSSOP packages.
The device is available in three standard resistance val-
ues: 10kΩ, 50kΩ, and 100kΩ. The DS1805 is specified
over the industrial temperature range. The DS1805
provides a low-cost alternative for designs based on
the DS1803, but require only a single potentiometer.
o
3V or 5V Operation
o
Low Power Consumption
o
One Digitally Controlled, 256-Position
Potentiometer
o
Compatible with DS1803-Based Designs
o
14-Pin TSSOP (173mil) and 16-Pin SO (150mil)
Available for Surface-Mount Applications
o
Three Address Inputs
o
Serial 2-Wire Bus
o
Operating Temperature Range
Industrial: -40°C to +85°C
o
Standard Resistance Values
DS1805-010: 10kΩ
DS1805-050*: 50kΩ
DS1805-100*: 100kΩ
Features
DS1805
Applications
CCFL Inverters
PDAs and Cell Phones
Portable Electronics
Multimedia Products
Instrumentation and Industrial Controls
Pin Configurations
TOP VIEW
Ordering Information
PART
DS1805E-010
TEMP RANGE
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
14 TSSOP (173mil)
14 TSSOP (173mil)
14 TSSOP (173mil)
16 SO (150mil)
16 SO (150mil)
16 SO (150mil)
RESISTANCE
(KΩ)
10
50
100
10
50
100
H1 1
L1
W1
2
3
14 V
CC
13 N.C.
12 N.C.
H1 1
N.C. 2
L1 3
W1 4
A2 5
A1 6
A0 7
GND 8
16 V
CC
15 N.C.
14 N.C.
DS1805E-050*
DS1805E-100*
DS1805Z-010
DS1805Z-050*
DS1805Z-100*
A2 4
A1 5
A0 6
GND 7
DS1805E
11 N.C.
10 N.C.
9
8
SDA
SCL
DS1805Z
13 N.C.
12 N.C.
11 N.C.
10 SDA
9
SCL
Add “/T&R” for tape-and-reel orders.
*Future product.
14 TSSOP (173mil)
16 SO (150mil)
______________________________________________
Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
Addressable Digital Potentiometer
DS1805
ABSOLUTE MAXIMUM RATINGS
Voltage on Any Pin Relative to Ground .................-0.5V to +6.0V
Operating Temperature Range ...........................-40°C to +85°C
Storage Temperature Range .............................-55°C to +125°C
Soldering Temperature............................................See IPC/JEDEC
J-STD-020A Specification
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.
RECOMMENDED DC OPERATING CONDITIONS
(T
A
= -40°C to +85°C)
PARAMETER
Supply Voltage
Resistor Inputs
SYMBOL
V
CC
L, H, W
(Note 1)
(Note 1)
CONDITIONS
MIN
2.7
-0.3
TYP
MAX
5.5
V
CC
+
0.3
UNITS
V
V
DC ELECTRICAL CHARACTERISTICS
(V
CC
= 2.7V to 5.5V, T
A
= -40°C to +85°C.)
PARAMETER
Supply Current Active
Input Leakage
Wiper Resistance
Wiper Current
Input Logic 1
Input Logic 0
SYMBOL
I
CC
I
IL
R
W
I
W
V
IH
V
IL
Input logic 1
Input Logic Levels A0, A1, A2
(Note 3)
Input logic 0
Input Current each I/O Pin
(Note 4)
Standby Current
Low-Level Output Voltage
I/O Capacitance
Pulse Width of Spikes that Must
be Suppressed by the Input Filter
I
STBY
V
OL1
V
OL2
C
I/0
t
SP
Fast mode
0
0.4V < V
I/O
< 0.9V
CC
(Note 5)
3mA sink current
6mA sink current
0
0
0.7V
CC
GND -
0.3
0.7V
CC
GND -
0.3
-10
20
(Note 2)
-1
400
CONDITIONS
MIN
TYP
MAX
200
+1
1000
1
V
CC
+
0.3
0.3V
CC
V
CC
+
0.3
V
0.25V
CC
+10
40
0.4
0.6
10
50
µA
µA
V
V
pF
ns
UNITS
µA
µA
Ω
mA
V
V
2
_____________________________________________________________________
Addressable Digital Potentiometer
ANALOG RESISTOR CHARACTERISTICS
(V
CC
= 2.7V to 5.5V, T
A
= -40°C to +85°C)
PARAMETER
End-to-End Resistor Tolerance
Absolute Linearity
Relative Linearity
-3dB Cutoff Frequency
Ratiometric Temperature Coefficient
End-to-End Temperature Coefficient
Capacitance
C
I
f
CUTOFF
SYMBOL
(Note 6)
(Note 7)
(Note 8)
(Note 9)
8
550
5
CONDITIONS
MIN
-20
-0.75
-0.3
TYP
MAX
+20
+0.75
+0.3
UNITS
%
LSB
LSB
Hz
ppm/°C
ppm/°C
pF
DS1805
AC ELECTRICAL CHARACTERISTICS
(V
CC
= 2.7V to 5.5V, T
A
= -40°C to +85°C)
PARAMETER
SCL Clock Frequency (Note 10)
Bus Free Time Between STOP
and START Condition (Note 10)
Hold Time (Repeated) START
Condition (Notes 10, 11)
Low Period of SCL Clock
(Note 10)
High Period of SCL Clock
(Note 10)
Data Hold Time
(Notes 10, 12, 13)
Data Setup Time
(Note 10)
Rise Time of Both SDA and SCL
Signals (Notes 10, 14)
Fall Time of Both SDA and SCL
Signals (Notes 10, 14)
Setup Time for STOP Condition
(Note 10)
Capacitive Load for Each Bus
Line (Note 14)
SYMBOL
f
SCL
t
BUF
t
HD:STA
t
LOW
t
HIGH
t
HD:DAT
t
SU:DAT
t
R
t
F
t
SU:STO
C
B
Fast mode
Standard mode
Fast mode
Standard mode
Fast mode
Standard mode
Fast mode
Standard mode
Fast mode
Standard mode
Fast mode
Standard mode
Fast mode
Standard mode
Fast mode
Standard mode
Fast mode
Standard mode
Fast mode
Standard mode
CONDITIONS
MIN
0
0
1.3
4.7
0.6
4.0
1.3
4.7
0.6
4.0
0
0
100
250
20 + 0.1C
B
20 + 0.1C
B
20 + 0.1C
B
20 + 0.1C
B
0.6
4.0
400
300
1000
300
300
0.9
0.9
TYP
MAX
400
100
UNITS
kHz
µs
µs
µs
µs
µs
ns
ns
ns
µs
pF
_____________________________________________________________________
3
Addressable Digital Potentiometer
DS1805
AC ELECTRICAL CHARACTERISTICS
(V
CC
= 2.7V to 5.5V, T
A
= -40°C to +85°C)
Note 1:
Note 2:
Note 3:
Note 4:
Note 5:
Note 6:
Note 7:
Note 8:
Note 9:
Note 10:
All voltages are referenced to ground.
I
CC
specified with SDA pin open. SCL = 400kHz clock rate.
Address inputs A0, A1, and A2 should be connected to either V
CC
or GND, depending on the desired address selections.
I/O pins of fast mode devices must not obstruct the SDA and SCL lines if V
CC
is switched off.
I
STBY
specified with SDA = SCL = V
CC
= 5.0V.
Valid at +25°C only.
Absolute linearity is used to determine wiper voltage versus expected voltage as determined by wiper position.
Relative linearity is used to determine the change in voltage between successive tap positions.
-3dB cutoff frequency characteristics for the DS1805 depend on potentiometer total resistance: DS1805-010, 1MHz;
DS1805-50, 200kHz; DS1805-100, 100kHz.
A fast mode device can be used in a standard mode system, but the requirement t
SU:DAT
> 250ns must then be met. This
will automatically be the case if the device does not stretch the low period of the SCL signal. If such a device does stretch
the LOW period of the SCL signal, it must output the next data bit to the SDA line t
RMAX
+ t
SU:DAT
= 1000ns + 250ns =
1250ns before the SCL line is released.
After this period, the first clock pulse is generated.
The maximum t
HD:DAT
has only to be met if the device does not stretch the low period (t
LOW
) of the SCL signal.
A device must internally provide a hold time of at least 300ns for the SDA signal (referred to the V
IHMIN
of the SCL signal)
in order to bridge the undefined region of the falling edge of SCL.
C
B
—total capacitance of one bus line in picofarads, timing referenced to (0.9)(V
CC
) and (0.1)(V
CC
).
Note 11:
Note 12:
Note 13:
Note 14:
4
_____________________________________________________________________
Addressable Digital Potentiometer
DS1805
Typical Operating Characteristics
(V
CC
= 5.0V, T
A
= +25°C, unless otherwise noted.)
SUPPLY CURRENT
vs. TEMPERATURE
DS1805 toc01
W-L RESISTANCE
vs. WIPER SETTING
DS1805 toc02
WIPER RESISTANCE vs.
WIPER VOLTAGE (10kΩ)
V
CC
= 5V
300
WIPER RESISTANCE (Ω)
250
V
CC
= 3V
200
150
100
50
0
DS1805 toc03
30
25
SUPPLY CURRENT (µA)
20
V
CC
= 3V
15
10
5
0
-40
-20
0
20
40
60
80
TEMPERATURE (°C)
V
CC
= 5V
350
10
W-L RESISTANCE (kΩ)
8
6
4
2
0
10kΩ POTENTIOMETER
0 25 50 75 100 125 150 175 200 225 250
WIPER SETTING
0
1
2
3
4
5
WIPER VOLTAGE (V)
VOLTAGE DIVIDER PERCENT CHANGE
(FROM +25°C) vs. TEMPERATURE
(RATIOMETRIC TC)
10kΩ POT
END-TO-END RESISTANCE % CHANGE
WIPER = 3Fh
WIPER = 7Fh
0.02
0
-0.02
-0.04
-0.06
-40
-20
WIPER = BFh
DS1805 toc04
END-TO-END RESISTANCE TEMPERATURE
CHANGE vs. TEMPERATURE
DS1805 toc05
ACTIVE SUPPLY CURRENT
vs. SCL FREQUENCY
45
ACTIVE SUPPLY CURRENT (µA)
40
35
30
25
20
15
10
5
0
SDA = VCC
A0, A1, A2, L1 = GND
W1, H1 = NO CONNECT
0
100
200
300
400
DS1805 toc06
0.06
0.04
% CHANGE (FROM +25°C)
5
4
3
2
1
0
-1
-2
-3
-4
-5
TC = 530ppm/°C
10kΩ, WORST CASE
50
WIPER = BFh
TC = 8.1ppm/°C
TC = 1.3ppm/°C
WIPER = 3Fh
0
20
40
60
80
TEMPERATURE (°C)
-40
-20
0
20
40
60
80
TEMPERATURE (°C)
SCL FREQUENCY (kHz)
VOLTAGE-DIVIDER ABSOLUTE LINEARITY
vs. WIPER SETTING (10kΩ)
DS1805 toc07
VOLTAGE-DIVIDER RELATIVE LINEARITY
vs. WIPER SETTING (10kΩ)
DS1805 toc08
0.18
0.16
ABSOLUTE LINEARITY (LSB)
0.14
0.12
0.10
0.08
0.06
0.04
0.02
0
0
50
100
150
200
0.06
0.05
RELATIVE LINEARITY (LSB)
0.04
0.03
0.02
0.01
0
-0.01
250
0
50
100
150
200
250
WIPER SETTING
WIPER SETTING
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