DS1841 Datasheet, PDF (1/16 Pages) Maxim Integrated Products – Temperature-Controlled, NV, I2C, Logarithmic Resistor

Rev 0; 11/07
Temperature-Controlled, NV, I²C,
Logarithmic Resistor
General Description
The DS1841 is a 7-bit, logarithmic, nonvolatile (NV) digi-
tal resistor that features an on-chip temperature sensor
and associated analog-to-digital converter (ADC). The
integrated temperature sensor indexes a 72-byte NV
lookup table (LUT) encompassing a temperature range
from -40°C to +100°C. The LUT output can drive the
resistor directly or be added to an NV initial-value regis-
ter (IVR) to drive the resistor. This flexible LUT-based
architecture allows the DS1841 to provide a tempera-
ture-compensated resistor output with arbitrary slope.
Programming is accomplished by an I²C-compatible
interface, which can operate at speeds of up to 400kHz.
Applications
Optical Transceivers
Linear and Nonlinear Compensation
Instrumentation and Industrial Controls
Mechanical Potentiometer Replacement
Registers and Modes are capitalized for clarity.
Features
♦ 22kΩ to 3.7kΩ Adjustable Logarithmic Resistor
with a 3.6kΩ Fixed Resistor
♦ 128 Wiper Tap Points
♦ On-Chip Temperature Sensor and ADC
♦ 72-Byte Lookup Table (LUT)
♦ I²C-Compatible Serial Interface
♦ Address Pins Allow Up to Four DS1841s to Share
the Same I²C Bus
♦ Digital Supply of 2.7V to 5.5V
♦ -40°C to +100°C Operating Range
♦ 3mm x 3mm, 10-Pin TDFN Package
Ordering Information
PART
TEMP RANGE
DS1841T+
-40°C to +100°C
DS1841T+T&R
-40°C to +100°C
+Denotes a lead-free package.
T&R = Tape and reel.
PIN-PACKAGE
10 TDFN
10 TDFN
Typical Operating Circuit
3.3V
4.7kΩ ^4.7kΩ
SDA
V_CC
SCL
GND
DS1841 _RH
RW
A1
A0
RGND
V_APD
V_OUT
0.1μF _DC-DC
CONVERTER
FB
100pF
APD BIAS CONTROL APPLICATION
Pin Configuration
TOP VIEW
SCL N.C. RH RW RGND
10 9 8 7 6
DS1841
*EP
12345
SDA GND V_CC A1 A0
TDFN
3.0mm × 3.0mm × 0.8mm
*EXPOSED PAD
________________________________________________________________ Maxim Integrated Products 1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.