DESCRIPTION

The DS1809 Dallastat is a nonvolatile digitally controlled potentiometer that provides 64 uniform wiper positions over the entire resistor range; including the high-end and low-end terminals of the device. The DS1809 is a low power, low voltage device capable of operating from power supplies of +2.7V to +5.5V. The device is ideal for low-power, portable, or battery powered applications.

Wiper position is maintained in the absence of power. This is accomplished via the use of an EEPROM cell array. The device provides for two storage methods, which include an auto-store capability and a command-initiated storage function. The EEPROM cell array is specified to accept greater than 50k writes. Storage of the wiper position is discussed in the Wiper Storage section of this datasheet.

Wiper positioning is controlled via a patented dual pushbutton (or contact closure) interface. For simple pushbutton-controlled applications or CPU-generated control signals, external debounce circuitry is not needed. The control interface will support both repetitive pulse inputs and continuous pulse (“push-and-hold”) inputs. Repetitive pulse and continuous pulse control as well as timing diagrams are discussed in the section entitled “OPERATION.”

The DS1809 is available in standard 10 kW , 50 kW, and 100 kW resistor versions. The DS1809 is provided as an industrial temperature grade part only. Available packaging for the DS1809 include an 8-lead (300-mil) DIP an 8-lead (150-mil) SOIC, and an 8-lead (118-mil) mSOP.

FEATURES

■ 64-position linear taper

■ Two nonvolatile wiper storage options

■ Operates from +2.7 to +5.5-volt supplies

■ Operating Temperature Range:

- Industrial: -40°C to +85°C

■ Electronic interface provides either digital or pushbutton control

■ Low-cost alternative to mechanical solutions

■ Standard Resistance Values

- DS1809-010 10 kW

- DS1809-050 50 kW

- DS1809-100 100 kW