Standard ICs replace mechanical potentiometers

Designated LS7190, LS7191, LS7192, LS7193, LS7194 and LS7195, these new devices are versions of a three-terminal digital potentiometer to replace mechanical potentiometers.

The clocks drive an internal 6-bit up/down counter with a count N ranging between 0 and 63 to correspond to 64 wiper-tap positions of a resistor chain consisting of 64 equal resistors.

The LS7190 and LS7193 interfaces with quadrature clocks from incremental encoders.

The LS7191/92 and LS7194/95 interfaces with non-quadrature up (A) and down (B) clocks. A and B inputs for LS7190/91 and LS7193/94 are debounced allowing these signals to be sourced from mechanical encoders or push-button switches.

A and B inputs for the LS7192 and LS7195 are not debounced so that fast clocks from electronic clock sources can be used.

They supply 3 to 5 volts and are available in 20K, 50K and 100K versions.

The LSI/CSI Digital Potentiometers are used as replacements for mechanical potentiometers and for potentiometer adjustments.

They can also be used for remote adjustments of instrumentation for gain, offset, time constant, line impedance matching, audio equipment volume control and more.

The devices feature an SPI interface for host MCU controllers. Supply voltage is 3V to 5V. They qualify for automotive temperature range and are available in SOIC-8, SOIC-14 and TSSOP-14 packages.

Applications:

• Replacement for mechanical potentiometer
• Potentiometer adjustment with mechanical Incremental Encoder
• Remote adjustment of instrumentation for gain, offset, time constant, line impedance matching, audio equipment volume control etc.