DESCRIPTION
The DS1800 is a dual audio-taper potentiometer designed specifically for use in the feedback path of the inverting configuration of an operational amplifier (see Figure 2). In this configuration, the DS1800 provides a VO /VI relationship of -20log(RF/RI), giving a gain/attenuation range covering +20 dB to -63 dB. Each potentiometer has a total of 129 positions including mute. The DS1800 provides five areas of resolution, which include: 0.25 dB per step from +20 dB to +3 dB; 0.5 dB per step from +3 dB to -12 dB; 1 dB from -12 dB to -27 dB; 2 dB per step from -27 dB to -47 dB; and 4 dB per step from -47 dB to -63 dB. The mute position provides 100 dB of attenuation.

FEATURES
■ Ultra-low power consumption
■ Operates from 3V or 5V supplies
■ Two digitally controlled, 128-position potentiometers including mute
■ Logarithmic gain characteristics
■ Zero-crossing detection eliminates noise caused by discrete wiper changes
■ Two control interfaces
   - 3-wire serial CPU control
   - Pushbutton control
■ 20-pin DIP (300-mil), 20-pin SOIV (300-mil), and 20-pin (173-mil) TSSOP packaging available
■ Operating Temperature Range:
   - Industrial: -40°C to +85°C
■ Software and hardware mute
■ Standard Resistance Available: 53KΩ