DS1804
NV Trimmer Potentiometer
www.dalsemi.com
FEATURES
Single 100-position taper potentiometer
Nonvolatile “on-demand” wiper storage
Operates from 3V or 5V supplies
Up/down, increment-controlled interface
Available in 8-pin (300-mil) DIP, 8-pin
(150-mil) SOIC, 8-pin (118-mil) µSOP, and
Flip Chip packages
Operating Temperature:
– Industrial:
-40ºC to +85ºC
Standard Resistance Values:
– DS1804-010 10 kΩ
– DS1804-050 50 kΩ
– DS1804-100 100 kΩ
PIN ASSIGNMENT
INC
U/D
H
GND
1
2
3
4
8
7
6
5
V
CC
CS
L
W
8-Pin DIP (300-mil)
8-Pin SOIC (150-mil)
8-Pin uSOP (118-mil)
8-Pin Flip Chip Package
See Mech. Drawings Section
PIN DESCIPTION
H
L
W
V
CC
CS
U/
D
INC
GND
-
-
-
-
-
-
-
-
High-Terminal of Potentiometer
Low-Terminal of Potentiometer
Wiper of Potentiometer
3V or 5V Power Supply
Chip Select
Up/Down Control
Increment/Decrement Wiper Control
Ground
DESCRIPTION
The DS1804 NV Trimmer Potentiometer is a nonvolatile digital potentiometer having 100 positions. The
device provides an ideal method for low-cost trimming applications using a CPU or manual control input
with minimal external circuitry. Wiper position of the DS1804 can be stored in EEPROM memory on
demand. The device’s wiper position is manipulated by a 3-terminal port that provides an increment/
decrement counter controlled interface. This port consists of the control inputs
CS
,
INC
, and U/
D
. The
DS1804 is available in three resistor grades, which include a 10 kΩ, 50 kΩ, and 100 kΩ. The device is
provided in an industrial temperature grade. Additionally, the DS1804 will operate from 3V or 5V
supplies and is ideal for portable application requirements. Three packaging options are available and
include the 8-pin (300-mil) DIP, 8-pin (150-mil) SOIC, 8-pin (118-mil) uSOP, and the Flip Chip
Package.
1 of 7
102699
DS1804
OPERATION
The DS1804 is a single nonvolatile potentiometer. The device has a total of 100 tap-points including the
L- and H- terminals. A total of 99 resistive segments exist between the L- and H- terminals. These tap-
points are accessible to the W-terminal, whose position is controlled via a 3-terminal control port. A
block diagram of the DS1804 is shown in Figure 1.
The 3-terminal port of the DS1804 provides an increment/decrement interface which is activated via a
chip select input. This interface consists of the input signals
CS
,
INC
, and U/
D
. These input signals
control a 7-bit up/down counter. The output of the 7-bit up/down counter controls a 1 of 100 decoder to
select wiper position. Additionally, this interface provides for a wiper storage operation using the
CS
and
INC
input control pins. The timing diagram for the 3-terminal interface control is shown in Figure 2.
PIN DESCRIPTIONS
V
CC
-
Power Supply. The DS1804 will support supply voltages ranging from +2.7 to +5.5 volts.
GND -
Ground.
H -
High-Terminal Potentiometer. This is the high terminal of the potentiometer. It is not required that
this terminal be connected to a potential greater than the L-terminal. Voltage applied to the H-terminal
can not exceed the power-supply voltage, V
CC
, or go below ground.
L -
Low-Terminal Potentiometer. This is the low terminal of the potentiometer. It is not required that this
terminal be connected to a potential less than the H-terminal. Voltage applied to the L-terminal cannot
exceed the power-supply voltage, V
CC
, or go below ground.
W
- Wiper of the Potentiometer. This pin is the wiper of the potentiometer. Its position on the resistor
array is controlled by the 3-terminal control port. Voltage applied to the wiper cannot exceed the power-
supply voltage, V
CC
, or go below ground.
-
Chip Select. The
CS
input is used to activate the control port of the DS1804. This input is active
low. When in a high-state, activity on the
INC
and U/
D
port pins will not affect or change wiper
position.
CS
-
Wiper Movement Control. This input provides for wiper position changes when the
CS
pin is low.
Wiper position changes of the W-terminal will occur one position per high-to-low transition of this input
signal. Position changes will not occur if the
CS
pin is in a high state.
INC
U/
D
-
Up/Down Control. This input sets the direction of wiper movement. When in a high state and
CS
is low, any high-to-low transition on
INC
will cause a one position movement of the wiper towards the
H-terminal. When in a low state and
CS
is low, any high-to-low transitions on
INC
will cause the
position of the wiper to move towards the L-terminal.
2 of 7
102699
DS1804
DS1804 BLOCK DIAGRAM
Figure 1
POWER-UP/POWER-DOWN CONDITIONS
On power-up the DS1804 will load the value of EEPROM memory into the wiper position register (or 1
of 100 decoder). The value of this register can then be set to another wiper position if desired, by using
the 3-terminal control port. On power-up, wiper position will be loaded within a maximum time period of
500
µs
once the power-supply is stable. Additionally, the 3-terminal interface port will be active after 50
ms.
On power-down, the wiper position register data will be lost. On the next device power-up, the value of
EEPROM memory will be loaded into the wiper position register.
On shipment from the factory, Dallas Semiconductor does not guarantee a specified EEPROM memory
value. This value should be set by the customer as needed.
NONVOLATILE WIPER STORAGE
Wiper position of the DS1804 can be stored using the
INC
and
CS
inputs. Storage of the wiper position
takes place, whenever the
CS
input transitions from low-to-high while the
INC
is high. Once this
condition has occurred the value of the current wiper position will be written to EEPROM memory.
The DS1804 is specified to accept 50,000 writes to EEPROM before a wear-out condition. After wear-out
the DS1804 will still function and wiper position can be changed during powered conditions using the 3-
terminal control port. However, on power-up the wiper-position will be indeterminate.
ONE TIME PROGRAMMABILITY (OTP)
The DS1804 can be easily used as an OTP device. The user of the DS1804 can trim the desired value of
the wiper position and set this position for storage as described above. Any activity through the 3-
terminal port can then be prevented by connecting the
CS
input pin to V
CC
. Also, an OTP application
does not adversely affect the number of times EEPROM is written, since EEPROM will only be loaded
and
not written
during a power-up or power-down condition.
On power-up the DS1804 will load the current value of EEPROM memory into the wiper position
register.
3 of 7
102699
DS1804
ABSOLUTE MAXIMUM RATINGS*
Voltage on Any Pin Relative to Ground
Operating Temperature
Storage Temperature
Soldering Temperature
-1.0V to +7.0V
-40°C to +85°C
-55°C to +125°C
260°C for 10 seconds
* This is a stress rating only and functional operation of the device at these or any other conditions above
those indicated in the operation sections of this specification is not implied. Exposure to absolute
maximum rating conditions for extended periods of time may affect reliability.
1. Insert A (Burn-in Disclaimer)
The Dallas Semiconductor DS1804 is built to the highest quality standards and manufactured for long
term reliability. All Dallas Semiconductor devices are made using the same quality materials and
manufacturing methods. However, the Flip Chip Package version of the DS1804 is not exposed to
environmental stresses, such as burn-in, that some industrial applications require. For specific reliability
information on this product, please contact the factory in Dallas at (972) 371-4448.
RECOMMENDED DC OPERATING CONDITIONS
PARAMETER
Supply Voltage
Input Logic 1
Input Logic 0
Resistor Inputs
SYMBOL
V
CC
V
IH
V
IL
L,H,W
MIN
+2.7
2.0
-0.5
GND-0.5
TYP
MAX
5.5
V
CC
+0.5
+0.8
+0.6
V
CC
+0.5
(-40°C to +85°C)
UNITS
V
V
V
V
NOTES
1
1,2
1,15
1,3
DC ELECTRICAL CHARACTERISTICS
PARAMETER
Supply Current
Input Leakage
Wiper Resistance
Wiper Current
Standby Current:
3 Volts
5 Volts
Wiper Load Time
Power-Up Time
SYMBOL
I
CC
I
LI
R
W
I
W
I
STBY
t
WLT
t
PU
-1
MIN
(-40°C to +85°C; V
CC
=2.7V to 5.5V)
TYP
MAX
400
+1
400
1000
1
10
20
500
50
40
UNITS
µA
µA
Ω
NOTES
4
mA
µA
µA
µs
ms
5
6
14
4 of 7
102699
DS1804
ANALOG RESISTOR CHARACTERISTICS
PARAMETER
End-to-End Resistor Tolerance
Absolute Linearity
Relative Linearity
-3 dB Cutoff Frequency
Temperature Coefficient
f
cutoff
SYMBOL
MIN
-20
(-40°C to +85°C;V
CC
=2.7V to 5.5V)
TYP
MAX
+20
±0.6
±0.25
UNITS
%
LSB
LSB
MHz
750
ppm/°C
NOTES
8
9
10
11
CAPACITANCE
PARAMETER
Input Capacitance
Output Capacitance
SYMBOL
C
IN
C
OUT
MIN
TYP
(25°C; V
CC
=2.7V to 5.5V)
MAX
5
7
UNITS
pF
pF
NOTES
12
12
AC ELECTRICAL CHARACTERISTICS
PARAMETER
CS
to
INC
(-40°C to +85°C; V
CC
=2.7V to 5.5V)
TYP
MAX
UNITS
ns
ns
ns
ns
ns
ns
200
500
ns
µs
ns
10
ms
NOTES
13
13
13
13
13
13
13
13
16
13,17
SYMBOL
t
CI
t
DI
t
IL
t
IH
t
IC
t
CPH
t
IW
t
R
, t
F
t
IK
t
WST
MIN
50
100
50
100
500
100
Setup
U/
D
to
INC
Setup
INC
INC
INC
CS
Low Period
High Period
inactive to
CS
Inactive
Deselect Time
Wiper Change to
INC
Low
INC
INC
Rise and Fall Times
Low to
CS
Inactive
50
Wiper Storage Time
5 of 7
102699
京公网安备 11010802033920号
EEWORLD
