X9251

Features:

• Four potentiometers in one package
• 256 resistor taps0.4% resolution
• SPI Serial Interface for write, read, and transfer operations of the potentiometer
• Wiper resistance: 100Ω typical @ VCC = 5V
• 4 Non-volatile data registers for each potentiometer
• Non-volatile storage of multiple wiper positions
• Standby current < 5µA max
• VCC: 2.7V to 5.5V Operation
• 50kΩ, 100kΩ versions of total resistance
• 100 yr. data retention
• Single supply version of X9250
• Endurance: 100,000 data changes per bit per register
• 24 Ld SOIC, 24 Ld TSSOP
• Low power CMOS
• Pb-free plus anneal available (RoHS compliant)




Application

• 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
• 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

Pinout






Specifications

Temperature under bias .............-65°C to +135°C
Storage temperature ..................-65°C to +150°C
Voltage on SCK, any address input, V_CC
with respect to VSS ............................... -1V to +7V
∆V = | (V_H - V_L) |...............................................5.5V
Lead temperature (soldering, 10s) .............300°C
IW (10s) .......................................................±6mA




Description

The X9251 integrates four digitally controlled potentiometers (XDCP) on a monolithic CMOS integrated circuit. The X9251 digitally controlled potentiometers are imple-mented with a combination of resistor elements and CMOS switches. The position of the wipers are controlled by the user through the SPI bus interface. Each potentiometer has associated with it a volatile Wiper Counter Register (WCR) and four non-volatile Data Registers that can be directly written to and read by the user. The content of the WCR controls the position of the wiper. At power-up, the X9251 recalls the content of the default Data Registers of each DCP (DR00, DR10, DR20, and DR30) to the corresponding 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.