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: 10k
, 50k, and 100k. 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.
Applications
CCFL Inverters
PDAs and Cell Phones
Portable Electronics
Multimedia Products
Instrumentation and Industrial Controls
Features
3V or 5V Operation
Low Power Consumption
One Digitally Controlled, 256-Position
Potentiometer
Compatible with DS1803-Based Designs
14-Pin TSSOP (173mil) and 16-Pin SO (150mil)
Available for Surface-Mount Applications
Three Address Inputs
Serial 2-Wire Bus
Operating Temperature Range
Industrial: -40C to +85C
Standard Resistance Values
DS1805-010: 10k
DS1805-050*: 50k
DS1805-100*: 100k
DS1805
Addressable Digital Potentiometer
______________________________________________ Maxim Integrated Products
1
14
13
12
11
10
9
8
1
2
3
4
5
6
7
V
CC
N.C.
N.C.
N.C.
A2
W1
L1
H1
TOP VIEW
N.C.
SDA
SCL
GND
A0
A1
14 TSSOP (173mil)
DS1805E
16
15
14
13
12
11
10
9
1
2
3
4
5
6
7
8
H1
V
CC
N.C.
N.C.
N.C.
N.C.
N.C.
SDA
SCL
16 SO (150mil)
N.C.
L1
A1
W1
A2
A0
GND
DS1805Z
Pin Configurations
Ordering Information
PART
TEM P RANGE
PIN- PACKAGE
RESISTANCE
( K
)
DS1805E-010
-40C to +85C
14 TSSOP (173mil)
10
DS1805E-050*
-40C to +85C
14 TSSOP (173mil)
50
DS1805E-100*
-40C to +85C
14 TSSOP (173mil)
100
DS1805Z-010
-40C to +85C
16 SO (150mil)
10
DS1805Z-050*
-40C to +85C
16 SO (150mil)
50
DS1805Z-100*
-40C to +85C
16 SO (150mil)
100
XX-XXXX; Rev 0; 4/02
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.
Add "/T&R" for tape-and-reel orders.
*Future product.
DS1805
Addressable Digital Potentiometer
2
_____________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
RECOMMENDED DC OPERATING CONDITIONS
(T
A
= -40C to +85C)
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.
Voltage on Any Pin Relative to Ground .................-0.5V to +6.0V
Operating Temperature Range ...........................-40C to +85C
Storage Temperature Range .............................-55C to +125C
Soldering Temperature............................................See IPC/JEDEC
J-STD-020A Specification
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Supply Voltage
V
CC
(Note 1)
2.7
5.5
V
Resistor Inputs
L, H, W
(Note 1)
-0.3
V
CC
+
0.3
V
DC ELECTRICAL CHARACTERISTICS
(V
CC
= 2.7V to 5.5V, T
A
= -40C to +85C.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Supply Current Active
I
CC
(Note 2)
200
A
Input Leakage
I
IL
-1
+1
A
Wiper Resistance
R
W
400
1000
Wiper Current
I
W
1
mA
Input Logic 1
V
IH
0.7V
CC
V
CC
+
0.3
V
Input Logic 0
V
IL
GND -
0.3
0.3V
CC
V
Input logic 1
0.7V
CC
V
CC
+
0.3
Input Logic Levels A0, A1, A2
(Note 3)
Input logic 0
GND -
0.3
0 . 2 5 V
C C
V
Input Current each I/O Pin
(Note 4)
0.4V < V
I/O
< 0.9V
CC
-10
+10
A
Standby Current
I
STBY
(Note 5)
20
40
A
V
OL1
3mA sink current
0
0.4
V
Low-Level Output Voltage
V
OL2
6mA sink current
0
0.6
V
I/O Capacitance
C
I/0
10
pF
Pulse Width of Spikes that Must
be Suppressed by the Input Filter
t
SP
Fast mode
0
50
ns
DS1805
Addressable Digital Potentiometer
_____________________________________________________________________
3
ANALOG RESISTOR CHARACTERISTICS
(V
CC
= 2.7V to 5.5V, T
A
= -40C to +85C)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
End-to-End Resistor Tolerance
(Note 6)
-20
+20
%
Absolute Linearity
(Note 7)
-0.75
+0.75
LSB
Relative Linearity
(Note 8)
-0.3
+0.3
LSB
-3dB Cutoff Frequency
f
CUTOFF
(Note 9)
Hz
Ratiometric Temperature Coefficient
8
ppm/C
End-to-End Temperature Coefficient
550
ppm/C
Capacitance
C
I
5
pF
AC ELECTRICAL CHARACTERISTICS
(V
CC
= 2.7V to 5.5V, T
A
= -40C to +85C)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Fast mode
0
400
SCL Clock Frequency (Note 10)
f
SCL
Standard mode
0
100
kHz
Fast mode
1.3
Bus Free Time Between STOP
and START Condition (Note 10)
t
BUF
Standard mode
4.7
s
Fast mode
0.6
Hold Time (Repeated) START
Condition (Notes 10, 11)
t
HD:STA
Standard mode
4.0
s
Fast mode
1.3
Low Period of SCL Clock
(Note 10)
t
LOW
Standard mode
4.7
s
Fast mode
0.6
High Period of SCL Clock
(Note 10)
t
HIGH
Standard mode
4.0
s
Fast mode
0
0.9
Data Hold Time
(Notes 10, 12, 13)
t
HD:DAT
Standard mode
0
0.9
s
Fast mode
100
Data Setup Time
(Note 10)
t
SU:DAT
Standard mode
250
ns
Fast mode
20 + 0.1C
B
300
Rise Time of Both SDA and SCL
Signals (Notes 10, 14)
t
R
Standard mode
20 + 0.1C
B
1000
ns
Fast mode
20 + 0.1C
B
300
Fall Time of Both SDA and SCL
Signals (Notes 10, 14)
t
F
Standard mode
20 + 0.1C
B
300
ns
Fast mode
0.6
Setup Time for STOP Condition
(Note 10)
t
SU:STO
Standard mode
4.0
s
Capacitive Load for Each Bus
Line (Note 14)
C
B
400
pF
DS1805
Addressable Digital Potentiometer
4
_____________________________________________________________________
Note 1:
All voltages are referenced to ground.
Note 2:
I
CC
specified with SDA pin open. SCL = 400kHz clock rate.
Note 3:
Address inputs A0, A1, and A2 should be connected to either V
CC
or GND, depending on the desired address selections.
Note 4:
I/O pins of fast mode devices must not obstruct the SDA and SCL lines if V
CC
is switched off.
Note 5:
I
STBY
specified with SDA = SCL = V
CC
= 5.0V.
Note 6:
Valid at +25
C only.
Note 7:
Absolute linearity is used to determine wiper voltage versus expected voltage as determined by wiper position.
Note 8:
Relative linearity is used to determine the change in voltage between successive tap positions.
Note 9:
-3dB cutoff frequency characteristics for the DS1805 depend on potentiometer total resistance: DS1805-010, 1MHz;
DS1805-50, 200kHz; DS1805-100, 100kHz.
Note 10: 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.
Note 11: After this period, the first clock pulse is generated.
Note 12: 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.
Note 13: 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.
Note 14: C
B
--total capacitance of one bus line in picofarads, timing referenced to (0.9)(V
CC
) and (0.1)(V
CC
).
AC ELECTRICAL CHARACTERISTICS
(V
CC
= 2.7V to 5.5V, T
A
= -40C to +85C)
Typical Operating Characteristics
(V
CC
= 5.0V, T
A
= +25
C, unless otherwise noted.)
DS1805
Addressable Digital Potentiometer
_____________________________________________________________________
5
VOLTAGE-DIVIDER ABSOLUTE LINEARITY
vs. WIPER SETTING (10k
)
DS1805 toc07
WIPER SETTING
ABSOLUTE LINEARITY (LSB)
200
150
50
100
0.04
0.06
0.08
0.10
0.12
0.14
0.16
0.18
0
0.02
0
250
VOLTAGE-DIVIDER RELATIVE LINEARITY
vs. WIPER SETTING (10k
)
DS1805 toc08
WIPER SETTING
RELATIVE LINEARITY (LSB)
200
150
100
50
0
0.01
0.02
0.03
0.04
0.05
0.06
-0.01
0
250
ACTIVE SUPPLY CURRENT
vs. SCL FREQUENCY
DS1805 toc06
SCL FREQUENCY (kHz)
ACTIVE SUPPLY CURRENT (
A)
300
200
100
5
10
15
20
25
30
35
40
45
50
0
0
400
SDA = VCC
A0, A1, A2, L1 = GND
W1, H1 = NO CONNECT
END-TO-END RESISTANCE TEMPERATURE
CHANGE vs. TEMPERATURE
DS1805 toc05
TEMPERATURE (
C)
END-TO-END RESISTANCE % CHANGE
60
40
-20
0
20
-4
-3
-2
-1
0
1
2
3
4
5
-5
-40
80
TC = 530ppm/
C
10k
, WORST CASE
VOLTAGE DIVIDER PERCENT CHANGE
(FROM +25
C) vs. TEMPERATURE
(RATIOMETRIC TC)
DS1805 toc04
TEMPERATURE (
C)
% CHANGE (FROM +25
C)
60
40
20
0
-20
-0.04
-0.02
0
0.02
0.04
0.06
-0.06
-40
80
10k
POT
WIPER = BFh
WIPER = BFh
WIPER = 3Fh
WIPER = 3Fh
WIPER = 7Fh
TC = 1.3ppm/
C
TC = 8.1ppm/
C
WIPER RESISTANCE vs.
WIPER VOLTAGE (10k
)
DS1805 toc03
WIPER VOLTAGE (V)
WIPER RESISTANCE (
)
4
3
2
1
50
100
150
200
250
300
350
0
0
5
V
CC
= 3V
V
CC
= 5V
W-L RESISTANCE
vs. WIPER SETTING
DS1805 toc02
WIPER SETTING
W-L RESISTANCE (k
)
225
200
175
150
125
100
75
50
25
2
4
6
8
10
0
0
250
10k
POTENTIOMETER
SUPPLY CURRENT
vs. TEMPERATURE
DS1805 toc01
TEMPERATURE (
C)
SUPPLY CURRENT (
A)
60
40
20
0
-20
5
10
15
20
25
30
0
-40
80
V
CC
= 5V
V
CC
= 3V
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