Log-domain low pass high pass first-order filter

A new first-order log-domain filter topology implementing simultaneously low-pass (LP) and high-pass (HP) filter functions has been presented. The circuit employs log-domain cells, current sources and grounded capacitor. The circuit has simple architecture, wider dynamic range at low power supply and higher frequency operation as it is based on log-exponential relation of a transistor. The electronic tunability of the proposed filter and grounded capacitor make it suitable for construction in IC technology. The PSPICE simulations results are found to be in close conformity with the theoretical results.