DS1800

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.

The DS1800 has two control interfaces (see Figure 1). The first is a 3-wire serial CPU interface  consisting of RST , CLK, and D. The second interface is a contact-closure interface, allowing easy pushbutton control without the need for external debounce or timing circuitry. The device also provides for software muting (via CPU) or hardware muting (MUTE control input). The hardware mute is a toggle type which returns the wiper positions to their prior states. Additional information on CPU and pushbutton control is described under the section entitled "OPERATION."

The DS1800 is available in 20-pin DIPs, SOICs, and TSSOPs. One standard resistance grade of 53 kΩ=is available for the device.