TPL8002-25,pdf(Tandem 64 Tap D

The TPL8002-25 is a programmable resistor device implementing two digital potentiometers with 64 wiper positions each that are tandem controlled through a 6-bit parallel interface. The device has fixed wiper resistances at the respective wiper contacts that tap the potentiometer resistors at a point determined by the binary code present at its digital inputs.

The resistive wiper tap terminals, RSW, of the TPL8002-25 are typically connected to the inverting inputs (¨C) of an external differential path inverting operational amplifier configuration, with the non-inverting inputs (+) connected through to ground. The application¡¯s differential input to the configuration is the device¡¯s RG terminals. The differential output of the external operational amplifiers is connected to the device¡¯s RF terminals, and thus becomes the differential output of the application configuration.

The resistance between the wiper contacts and the end points RG and RF of the TPL8002-25 provides a logarithmic gain/attenuation response of the configuration. With a digital code of decimal 0 (b000000) the configuration has an inverting maximum attenuation of ¨C24 dB. With a digital code of decimal 32 (b100000) the configuration has inverting unity gain of 0.00 dB. With a digital code of decimal 63 (b111111) the configuration has an inverting maximum gain of +23.25 dB. The response of the configuration with respect to the digital code varies in fixed steps of 0.75 dB.