ISL23418 Datasheet, PDF (1/20 Pages) Intersil Corporation – Single, 128-Tap, Low Voltage Digitally Controlled Potentiometer (XDCP™)

Single, 128-Tap, Low Voltage Digitally Controlled
Potentiometer (XDCP™)
ISL23418
The ISL23418 is a volatile, low voltage, low noise, low power,
SPI™ 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 wiper is controlled by the user through the SPI
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 ISL23418 wiper always
commences at mid-scale (64-tap position).
The low voltage, low power consumption, and small package
size of the ISL23418 make it an ideal choice for use in battery
operated equipment. The ISL23418 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
ISL23418 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.
Related Literature
• See ISL23415, “Single, Low Voltage Digitally Controlled
Potentiometer (XDCP™)”
Features
• 128 Resistor Taps
• SPI Serial Interface
- No Additional Level Translator for Low Bus Supply
- Daisy Chaining of Multiple DCP
• Wiper Resistance: 70Ω Typical @ V_CC = 3.3V
• Shutdown Mode: Forces DCP into End-to-end Open Circuit;
RW Shorted to RL Internally
• Power-on Preset to Mid-scale (64-tap Position)
• Shutdown and Standby Current <2.8µA Max
• Power Supply
- V_CC = 1.7V to 5.5V Analog Power Supply
- V_LOGIC = 1.2V to 5.5V SPI Bus/Logic Power Supply
• 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 µTQFN Packages
• Pb-free (RoHS compliant)
Applications
• Power Supply Margining
• RF Power Amplifier Bias Compensation
• LCD Bias Compensation
• Gain Adjustment in Battery Powered Instruments
• Portable Medical Equipment Calibration
10000
8000
6000
4000
2000
0
0
25
50
75
100
125
TAP POSITION (DECIMAL)
FIGURE 1. FORWARD AND BACKWARD RESISTANCE vs TAP
POSITION, 10k
VREF
RH1
ISL23418
RW1
RL1
-
+
ISL28114
VREF_M
FIGURE 2. V_REF ADJUSTMENT
August 3, 2011
1
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
FN7901.0
1-888-INTERSIL or 1-888-468-3774 |Copyright Intersil Americas Inc. 2011. All Rights Reserved
XDCP is a trademark of Intersil Americas Inc. Intersil (and design) is a trademark owned by Intersil Corporation
or one of its subsidiaries .All other trademarks mentioned are the property of their respective owners.