The X9409 integrates 4 digitally controlled potentiometers
(XDCP) on a monolithic CMOS integrated microcircuit.
The digitally 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 2-wire bus interface. Each potentiometer
has associated with it a volatile Wiper Counter Register (WCR)
and 4 nonvolatile Data Registers (DR0:DR3) 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
through the switches. Power-up recalls the contents of 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.

Features
• Four potentiometers per package
• 64 resistor taps
• 2-wire serial interface for write, read and transfer operations
of the potentiometer
• 50Ω wiper resistance, typical at 5V
• Four nonvolatile data registers for each potentiometer
• Nonvolatile storage of multiple wiper position
• Power-on recall. Loads saved wiper position on power-up
standby current < 1µA typical
• System VCC: 2.7V operation
• 10kΩ end-to-end resistance
• 100 year data retention
• Endurance: 100,000 data changes per bit per register
• Low power CMOS
• 24 Ld TSSOP
• Pb-free (RoHS compliant)