The DS3908 contains two nonvolatile digital poten-
tiometers with programmable-gain amplifiers buffering
the wiper outputs. The potentiometer position and
amplifier gain are controlled through an I
2
C-compatible
serial bus. The DS3908 operates in both 3.3V and 5V
systems and features a write-protect pin that locks the
position of the potentiometers and gain registers. Up to
eight DS3908s can be placed on a single I
2
C bus.
Features
♦
Two 64-Position Linear Taper Potentiometers
♦
Integral Wiper Buffering Amplifiers with
Selectable Gains of 1V/V, 2V/V, or 4V/V
♦
100kΩ Potentiometer End-to-End Resistance
♦
Low Potentiometer Temperature Coefficient
♦
Nonvolatile Wiper and Gain Storage
♦
I
2
C-Compatible Interface
♦
Write-Protect Pin Prevents Accidental Field
Reprogramming
♦
3V to 5.5V Supply Voltage Range
♦
-40°C to +85°C Operating Temperature Range
♦
14-Pin TDFN Package
DS3908
Applications
Pin-Diode Biasing
Power-Supply Calibration
Cell Phones and PDAs
Portable Electronics
PART
DS3908N+
Ordering Information
TEMP RANGE
-40°C to +85°C
PIN-PACKAGE
14 TDFN
+Denotes
lead-free package.
Typical Operating Circuit
TOP VIEW
V
CC
POT0
H0
PGA0
V0
L0
I
2
C
INTERFACE
POT1
PGA1
H1
VOLTAGE
REFERENCE
NV ADJUSTABLE
REFERENCE
VOLTAGE
Pin Configuration
SDA
SCL
A0
A1
A2
1
2
3
4
14 V
CC
13 H1
12 V1
11 L1
+
DS3908
SDA
SCL
A0
A1
A2
WP
DS3908
5
6
7
10 H0
9
8
V0
L0
V1
L1
NV ADJUSTABLE
REFERENCE
VOLTAGE
WP
GND
TDFN (3mm x 3mm)
______________________________________________
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.
Dual, 64-Position Nonvolatile Digital
Potentiometer with Buffered Outputs
DS3908
ABSOLUTE MAXIMUM RATINGS
Voltage on V
CC
, SDA, and SCL Relative to GND .....-0.5V to +6.0V
Voltage on A0, A1, A2, L0, L1, H0, H1, and WP Relative
to GND................-0.5V to (V
CC
+ 0.5V) (not to exceed +6.0V)
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 ............Refer to J-STD-020 Specification
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.