DS3904 Datasheet, PDF (1/11 Pages) Dallas Semiconductor – Triple 128-Position Nonvolatile Digital Variable Resistor/Switch

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.
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
Features
♦ 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
Ordering Information
PART
TEMP RANGE
PIN-
(R0/R1/R2)
PACKAGE RESISTANCE (k
)
DS3904U-010 -40°C to +85°C 8 μSOP 20/10/20 + High-Z
DS3904U-020 -40°C to +85°C 8 μSOP 20/20/20 + High-Z
DS3905U-020 -40°C to +85°C 10 μSOP 20/20/20 + High-Z
Pin Configurations
TOP VEIW
SDA ₁
SCL ₂
V_CC 3
GND 4
DS3904
μSOP
8 A0
7 H0
6 H1
5 H2
A1 ₁
SDA ₂
SDL 3
V_CC 4
GND 5
DS3905
μSOP
10 A2
9 A0
8 H0
7 H1
6 H2
Typical Operating Circuit
0.1μF
VCC
DS3904/DS3905
VCC
4.7kΩ 4.7kΩ
RESISTOR 0
ADDR F8h
2-WIRE
MASTER
(DS3905 ONLY)
SCL
SDA
RESISTOR 1
A0
ADDR F9h
A1
A2
RESISTOR 2
ADDR FAh
GND
VCC
R10
RHIZ
H0
VCC
INTERFACE EXAMPLES
VARIABLE RESISTANCE
FOR ADJUSTABLE
CURRENT SOURCE
R11
RHIZ
H1
VIN
DIGITAL
LOGIC
2-WIRE
ADDRESSABLE
SWITCH (USING 00h
AND RHIZ SETTINGS)
RHIZ
H2
GAIN
CONTROL
R12
_____________________________________________ 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.