ISL23318_14 Datasheet, PDF (1/19 Pages) Intersil Corporation – Single, 128-taps Low Voltage Digitally Controlled Potentiometer (XDCP™)

Single, 128-taps Low Voltage Digitally Controlled
Potentiometer (XDCP™)
ISL23318
The ISL23318 is a volatile, low voltage, low noise, low power,
I²C Bus™, 128 Taps, single digitally controlled potentiometer
(DCP), which integrates DCP core, wiper switches and control
logic on a monolithic CMOS integrated circuit.
The digitally controlled potentiometer is implemented with a
combination of resistor elements and CMOS switches. The
position of the wipers are controlled by the user through the
I²C bus interface. The potentiometer has an associated
volatile Wiper Register (WR) that can be directly written to and
read by the user. The contents of the WR controls the position
of the wiper. When powered on, the ISL23318’s wiper will
always commence at mid-scale (64 tap position).
The low voltage, low power consumption, and small package
of the ISL23318 make it an ideal choice for use in battery
operated equipment. In addition, the ISL23318 has a V_LOGIC
pin allowing down to 1.2V bus operation, independent from the
V_CC value. This allows for low logic levels to be connected
directly to the ISL23318 without passing through a voltage
level shifter.
The DCP can be used as a three-terminal potentiometer or as a
two-terminal variable resistor in a wide variety of applications
including control, parameter adjustments, and signal
processing.
Features
• 128 resistor taps
• I²C serial interface
- No additional level translator for low bus supply
- Two address pins allow up to four devices per bus
• Power supply
- V_CC = 1.7V to 5.5V analog power supply
- V_LOGIC = 1.2V to 5.5V I²C bus/logic power supply
• Wiper resistance: 70Ω typical @ V_CC = 3.3V
• Shutdown Mode - forces the DCP into an end-to-end open
circuit and R_W is shorted to R_L internally
• Power-on preset to mid-scale (64 tap position)
• Shutdown and standby current <2.8µA max
• DCP terminal voltage from 0V to V_CC
• 10kΩ, 50kΩ or 100kΩ total resistance
• Extended industrial temperature range: -40°C to +125°C
• 10 Ld MSOP or 10 Ld UTQFN packages
• Pb-free (RoHS compliant)
Applications
• Gain adjustment in battery powered instruments
• Trimming sensor circuits
• Power supply margining
• RF power amplifier bias compensation
10000
8000
6000
4000
2000
0
0
32
64
96
128
TAP POSITION (DECIMAL)
FIGURE 1. FORWARD AND BACKWARD RESISTANCE vs TAP
POSITION, 10k DCP
VREF
RH
RW
ISL23318
RL
-
+
ISL28114
VREF_M
FIGURE 2. V_REF ADJUSTMENT
July 26, 2011
1
FN7887.0
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
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