X9421
Single Digitally Controlled (XDCP™) Potentiometer
Not Recommended for New Designs.
Recommended Replacement Parts ISL22416, ISL22419.
Typical Diagram
Key Features
- Single Voltage Potentiometer
- 64 Resistor Taps
- SPI Serial Interface for Write, Read, and Transfer Operations of the Potentiometer
- Wiper Resistance, 150Ω Typical at 5V
- 4 Non-Volatile Data Registers
- Non-Volatile Storage of Multiple Wiper Positions
- Power-on Recall. Loads Saved Wiper Position on Power-up.
- Standby Current < 5µA Max
- VCC: 2.7V to 5.5V Operation
- 2.5kΩ, 10kΩ End to End Resistance
- 100 yr. Data Retention
- Endurance: 100, 000 Data Changes per Bit per Register
- 14 Ld TSSOP, 16 Ld SOIC
- Low Power CMOS
- Pb-Free Available (RoHS Compliant)
Description
The X9421 integrates a single digitally controlled potentiometer (XDCP) on a monolithic CMOS integrated circuit.
The digital controlled potentiometer is implemented using 63 resistive elements in a series array. Between each element are tap points connected to the wiper terminal through switches. The position of the wiper on the array is controlled by the user through the SPI bus interface. The potentiometer has associated with it a volatile Wiper Counter Register (WCR) and a four non-volatile Data Registers that can be directly written to and read by the user. The contents of the WCR controls the position of the wiper on the resistor array though the switches. Power-up recalls the contents of the default data register (DR0) to the WCR.
The XDCP 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.
Applications
- CIRCUIT LEVEL APPLICATIONS
- Vary the gain of a voltage amplifier
- Provide programmable dc reference voltages for comparators and detectors
- Control the volume in audio circuits
- Trim out the offset voltage error in a voltage amplifier circuit
- Set the output voltage of a voltage regulator
- Trim the resistance in Wheatstone bridge circuits
- Control the gain, characteristic frequency and Q-factor in filter circuits
- Set the scale factor and zero point in sensor signal conditioning circuits
- Vary the frequency and duty cycle of timer ICs
- Vary the dc biasing of a pin diode attenuator in RF circuits
- Provide a control variable (I, V, or R) in feedback circuits
SYSTEM LEVEL APPLICATIONS
- Adjust the contrast in LCD displays
- Control the power level of LED transmitters in communication systems
- Set and regulate the DC biasing point in an RF power amplifier in wireless systems
- Control the gain in audio and home entertainment systems
- Provide the variable DC bias for tuners in RF wireless systems
- Set the operating points in temperature control systems
- Control the operating point for sensors in industrial systems
- Trim offset and gain errors in artificial intelligent systems
