DS1855
Dual Nonvolatile Digital Potentiometer
and Secure Memory
www.maxim-ic.com
FEATURES
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Two linear taper potentiometers
-
DS1855-010 (one 10k, 100 position and
one 10k, 256 position)
-
DS1855-020 (one 10k, 100 position and
one 20k, 256 position)
-
DS1855-050 (one 10k, 100 position and
one 50k, 256 position)
-
DS1855-100 (one 10k, 100 position and
one 100k, 256 position)
256 bytes of EEPROM memory
Access to data and potentiometer control via
a 2-wire interface
External write-protect pin to protect data and
potentiometer settings
Data and potentiometer settings also can be
write-protected through software control
Nonvolatile wiper storage
Operates from 3V or 5V supplies
Packaging: 14-pin TSSOP, 16-ball STPBGA,
flip-chip package
Industrial operating temperature:
-40ºC to +85ºC
Programming temperature: 0ºC to +85ºC
SDA
SCL
A0
A1
A2
WP
GND
1
2
3
4
5
6
14
13
12
11
10
9
Vcc
H0
W1
H1
L1
W0
L0
7
8
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§
§
§
§
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14-Pin TSSOP (173-mil)
Top View
A
B
C
D
1
2
3
4
16-Ball STPBGA (4mm x 4mm)
14-Pin Flip Chip (100-mil x 100-mil)
(Not
Shown)
DESCRIPTION
The DS1855 dual nonvolatile (NV) digital potentiometer and secure memory consists of one 100-position
linear taper potentiometer, one 256-position linear taper potentiometer, 256 bytes of EEPROM memory,
and a 2-wire interface. The DS1855, which features a new software write protect, is an upgrade of the
DS1845. The DS1855 provides an ideal method for setting bias voltages and currents in control
applications using a minimum of circuitry. The EEPROM memory allows a user to store configuration or
calibration data for a specific system or device as well as provide control of the potentiometer wiper
settings. Any type of user information may reside in the first 248 bytes of this memory. The next two
addresses of EEPROM memory are for potentiometer settings and the remaining 6 bytes of memory are
reserved. These reserved and potentiometer registers should not be used for data storage. Access to this
EEPROM is via an industry-standard 2-wire bus. The interface I/O pins consist of SDA and SCL. The
wiper position of the DS1855, as well as EEPROM data, can be write-protected through hardware using
the
write-protect
input
pin
(WP)
or
software
using
the
2-wire
interface.
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