Implementing Programmable T-Networks Using Xicor Digitally Controlled Potentiometers (XDCPs)The Basics
A common topology found in many analog circuits is the T-network, so called because its schematic representation resembles the letter "T". T-networks are two port structures used as building blocks in amplifiers, filters, oscillators and conversion circuits.
Traditionally, T-networks networks have been constructed using discrete resistors and capacitors. When the discrete resistors are replaced with XDCPs, we have a new structure called a Programmable T-network.