Rev 3; 3/07
Triple 128-Position Nonvolatile Digital
Variable Resistor/Switch
General Description
The DS3904/DS3905 contain three nonvolatile (NV) low
temperature coefficient, variable digital resistors. Each
resistor has 128 user-selectable positions. Additionally,
the DS3904/DS3905 have a high-impedance setting that
allows each resistor to function as a digital switch. The
DS3904/DS3905 can operate over a 2.7V to 5.5V supply
voltage range, and communication with the device is
achieved through a 2-wire serial interface. Address pins
allow multiple DS3904/DS3905s to operate on the same
two-wire bus. The DS3904 has one address pin, allow-
ing two DS3904s to share the bus, while the DS3905
has three address pins, allowing up to eight DS3905s to
share a common bus. The low-cost and small size of the
DS3904/DS3905 make them ideal replacements for con-
ventional mechanical trimming resistors.
Features
Ω
Ω
Ω
♦
Three 20kΩ, or Two 20kΩ and One 10kΩ
,
128-
Position Linear Digital Resistors
♦
Resistor Settings are Stored in NV Memory
♦
Each Resistor has a High-Impedance Setting for
Switch Operation to Control Digital Logic
♦
Low Temperature Coefficient
♦
2-Wire Serial Interface
♦
2.7V to 5.5V Operating Range
♦
-40°C to +85°C Industrial Temperature
♦
Packaging: 8-Pin
µSOP
for DS3904, 10-pin
µSOP
for DS3905
DS3904/DS3905
Ordering Information
PART
TEMP RANGE
PIN-
(R0/R1/R2)
PACKAGE RESISTANCE (k )
20/10/20 + High-Z
20/20/20 + High-Z
20/20/20 + High-Z
Applications
Power-Supply Calibration
Cell Phones and PDAs
Fibre Optic Transceiver Modules
Portable Electronics
Small and Low-Cost Replacement for
Conventional Mechanical Trimming Resistors/
Dip Switches
Test Equipment
DS3904U-010
-40°C to +85°C 8 μSOP
DS3904U-020
-40°C to +85°C 8 μSOP
DS3905U-020
-40°C to +85°C 10 μSOP
Pin Configurations
TOP VEIW
SDA 1
SCL 2
V
CC
3
GND
4
8
7
A0
H0
H1
H2
A1 1
SDA 2
SDL 3
V
CC
GND
4
5
10 A2
9
A0
H0
H1
H2
DS3904
6
5
DS3905
8
7
6
μSOP
μSOP
Typical Operating Circuit
INTERFACE EXAMPLES
V
CC
V
CC
DS3904/DS3905
0.1μF
4.7kΩ
2-WIRE
MASTER
4.7kΩ
SCL
SDA
RESISTOR 1
ADDR F9h
RHIZ
H1
R
11
DIGITAL
LOGIC
2-WIRE
ADDRESSABLE
SWITCH (USING 00h
AND RHIZ SETTINGS)
V
CC
RESISTOR 0
ADDR F8h
RHIZ
H0
V
CC
R
10
VARIABLE RESISTANCE
FOR ADJUSTABLE
CURRENT SOURCE
A0
(DS3905 ONLY)
A1
A2
V
IN
RHIZ
RESISTOR 2
ADDR FAh
H2
GAIN
CONTROL
GND
R
12
_____________________________________________
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.
Triple 128-Position Nonvolatile
Variable Digital Resistor/Switch
DS3904/DS3905
ABSOLUTE MAXIMUM RATINGS
Voltage on V
CC
Pin Relative to Ground.................-0.5V to +6.0V
Voltage on SDA, SCL, A0, A1, A2
Relative to Ground*...................................-0.5V to V
CC
+ 0.5V
Voltage on H0, H1, and
H2 Relative to Ground .......................................-0.5V to +6.0V
Current Through H0, H1, and H2..........................................3mA
Operating Temperature Range ...........................-40°C to +85°C
Programming Temperature Range .........................0°C to +70°C
Storage Temperature Range .............................-55°C to +125°C
Soldering Temperature...................See J-STD-020 Specification
*This voltage must not exceed 6.0V.
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
Input Logic 1
Input Logic 0
Resistor Current
Resistor Terminals H0, H1, H2
SYMBOL
V
CC
V
IH
V
IL
I
R
V
CC
= +2.7V to +5.5V
-0.3
(Note 1)
CONDITIONS
MIN
2.7
0.7 x
V
CC
-0.3
TYP
MAX
5.5
V
CC
+
0.3
0.3 x
V
CC
3
+5.5
UNITS
V
V
V
mA
V
DC ELECTRICAL CHARACTERISTICS
(V
CC
= +2.7V to +5.5V, T
A
= -40°C to +85°C, unless otherwise noted.)
PARAMETER
Input Leakage
Standby Supply Current
Low-Level Output Voltage (SDA)
SYMBOL
I
L
I
STBY
V
OL1
V
OL2
CONDITIONS
(Note 2)
V
CC
= 3V (Note 3)
V
CC
= 5V (Note 3)
3mA sink current
6mA sink current
0
0
MIN
-1
TYP
95
145
MAX
+1
200
200
0.4
0.6
UNITS
µA
µA
V
ANALOG RESISTOR CHARACTERISTICS
(V
CC
= +2.7V to +5.5V, T
A
= -40°C to +85°C, unless otherwise noted.)
PARAMETER
Absolute Linearity (Note 4)
Relative Linearity (Note 5)
Temperature Coefficient (Note 6)
SYMBOL
INL
DNL
20k
10k
20k
10k
resistor
resistor
resistor
resistor
resistor)
resistor)
CONDITIONS
MIN
-1
-1
-0.5
-0.5
-200
-150
+123
+173
TYP
MAX
+1
+1
+0.5
+0.5
+400
+450
UNITS
LSB
LSB
ppm/°C
Position 7Fh (20k
Position 7Fh (10k
2
______________________________________________________________________
Triple 128-Position Nonvolatile Digital
Variable Resistor/Switch
ANALOG RESISTOR CHARACTERISTICS (continued)
(V
CC
= +2.7V to +5.5V, T
A
= -40°C to +85°C, unless otherwise noted.)
PARAMETER
Position 7Fh Resistance
Position 00h Resistance
High Impedance
SYMBOL
R
MAX
R
MIN
R
HIZ
CONDITIONS
T
A
= +25°C (20k resistor)
T
A
= +25°C (10k
T
A
= +25°C
resistor)
MIN
14.5
8
200
5.5
TYP
20
10
MAX
25.5
12
500
M
UNITS
k
DS3904/DS3905
AC ELECTRICAL CHARACTERISTICS
(V
CC
= +2.7V to +5.5V, T
A
= -40°C to +85°C.)
PARAMETER
SCL Clock Frequency
(Note 7)
Bus Free Time between STOP
and START Conditions (Note 7)
Hold Time (Repeated) START
Condition (Notes 7, 8)
Low Period of SCL Clock
(Note 7)
High Period of SCL Clock
(Note 7)
Data Hold Time
(Notes 7, 9)
Data Setup Time
(Note 7)
Start Setup Time
Rise Time of Both SDA and SCL
Signals (Note 10)
Fall Time of Both SDA and SCL
Signals (Note 10)
Setup Time for STOP Condition
Capacitive Load for Each Bus
Line
EEPROM Write Time
Startup Time
SYMBOL
f
SCL
t
BUF
t
HD:STA
t
LOW
t
HIGH
t
HD:DAT
t
SU:DAT
t
SU:STA
t
R
t
F
t
SU:STO
C
B
t
W
t
ST
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
Fast mode
Standard mode
(Note 10)
(Note 11)
10
CONDITIONS
MIN
0
0
1.3
4.7
0.6
4.0
1.3
4.7
0.6
4.0
0
0
100
250
0.6
4.7
20 + 0.1C
B
20 + 0.1C
B
20 + 0.1C
B
20 + 0.1C
B
0.6
4.0
400
20
2
300
1000
300
300
0.9
0.9
TYP
MAX
400
100
UNITS
kHz
µs
µs
µs
µs
µs
ns
µs
ns
ns
µs
pF
ms
ms
_____________________________________________________________________
3
Triple 128-Position Nonvolatile Digital
Variable Resistor/Switch
DS3904/DS3905
NONVOLATILE MEMORY CHARACTERISTICS
(V
CC
= +2.7V to +5.5V, T
A
= +70°C.)
PARAMETER
EEPROM Writes
SYMBOL
CONDITIONS
MIN
50,000
TYP
MAX
UNITS
All voltages are referenced to ground.
Applies to A0, SDA, SCL for the DS3904 and A0, A1, A2, SDA, SCL for the DS3905. Also applies to H0, H1,
H2 for both DS3904 and DS3905 when in the high-impedance state.
Note 3:
I
STBY
specified with SDA = SCL = V
CC
and A0 = GND.
Note 4:
Absolute linearity is used to determine expected resistance. Absolute linearity is defined as the deviation
from the straight line drawn from the value of the resistance at position 00h to the value of the resistance at
position 7Fh.
Note 5:
Relative linearity is used to determine the change of resistance between two adjacent resistor positions.
Note 6:
Temperature coefficient specifies the change in resistance as a function of temperature. The temperature
coefficient varies with resistor position. Limits are guaranteed by design.
Note 7:
A fast-mode device can be used in a standard-mode system, but the requirement t
SU:DAT
> 250ns must
then be met. This is automatically 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 8:
After this period, the first clock pulse is generated.
Note 9:
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 10:
C
B
—total capacitance of one bus line in picofarads, timing referenced to 0.9 x V
CC
and 0.1 x V
CC
.
Note 11:
EEPROM write begins after a stop condition occurs.
Note 1:
Note 2:
4
______________________________________________________________________
Triple 128-Position Nonvolatile Digital
Variable Resistor/Switch
Typical Operating Characteristics
(V
CC
= +5.0V, T
A
= +25°C, unless otherwise noted.)
SUPPLY CURRENT
vs. TEMPERATURE
DS3904/5 toc01
DS3904/DS3905
SUPPLY CURRENT
vs. SCL FREQUENCY
180
160
SUPPLY CURRENT (μA)
140
120
100
80
60
40
20
0
0
0
50
100 150 200 250 300 350 400
SCL FREQUENCY (kHz)
0
25
5
V
CC
= SDA = +5V
ADDRESS PINS
CONNECTED TO GND
DS3904/5 toc02
RESISTANCE vs.
RESISTOR SETTING
DS3904/5 toc03
160
140
SUPPLY CURRENT (μA)
120
100
80
60
40
20
0
-40
-20
0
20
40
60
SDA = SCL =V
CC
ADDRESS PINS
CONNECTED TO GND
V
CC
= +5V
V
CC
= +3V
200
25
20
RESISTANCE (kΩ)
20kΩ RESISTOR
15
10
10kΩ RESISTOR
50
75
100
125
80
TEMPERATURE (°C)
RESISTOR SETTING (DEC)
TEMPERATURE COEFFICIENT vs.
RESISTOR SETTING
DS3904/5 toc04
TEMPERATURE COEFFICIENT vs.
RESISTOR SETTING
DS3904/5 toc05
POSITION 7Fh RESISTANCE PERCENT CHANGE
FROM +25°C vs. TEMPERATURE
RESISTANCE % CHANGE (FROM +25°C)
DS3904/5 toc06
600
TEMPERATURE COEFFICIENT (ppm/°C)
20kΩ RESISTOR
500
400
300
200
100
0
-100
-200
0
20
40
60
80
100
120
RESISTOR SETTING (DEC)
TC OF +25°C TO +85°C
TC OF +25°C TO -40°C
900
TEMPERATURE COEFFICIENT (ppm/°C)
800
700
600
500
TC OF +25°C TO +85°C
400
300
200
100
0
0
20
40
60
80
100
120
RESISTOR SETTING (DEC)
TC OF +25°C TO -40°C
10kΩ RESISTOR
1.0
0.8
0.6
20kΩ RESISTOR
0.4
0.2
0
-0.2
-0.4
-40
-20
0
20
40
60
80
TEMPERATURE (°C)
10kΩ RESISTOR
POSITION 00h RESISTANCE PERCENT CHANGE
FROM +25°C vs. TEMPERATURE
DS3904/5 toc07
RESISTANCE vs. POWER-UP VOLTAGE
DS3904/5 toc08
RESISTANCE vs. POWER-DOWN VOLTAGE
90
80
RESISTANCE (kΩ)
70
60
50
40
30
20
10
0
PROGRAMMED RESISTANCE
EEPROM RECALL
>5.5MΩ
DS3904/5 toc09
RESISTANCE % CHANGE (FROM +25°C)
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0
-0.5
-1.0
-1.5
-2.0
-2.5
-40
-20
0
20
10kΩ RESISTOR
100
90
80
RESISTANCE (kΩ)
70
60
50
40
30
20
10
0
PROGRAMMED RESISTANCE
EEPROM RECALL
>5.5MΩ
100
20kΩ RESISTOR
40
60
80
0
1
2
3
4
5
6
0
1
2
3
4
5
6
TEMPERATURE (°C)
POWER-UP VOLTAGE (V)
POWER-DOWN VOLTAGE (V)
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5
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