Abstract:

In order to design a current mode filter which has the property of current controllability, the linear transformation filters by employing current mirrors as the elementary active elements are proposed. Based on the linear transformation, a simple and systematic design table is given to realize currentmode filters using current mirror. Using the proposed design table, all pole and elliptic filters can be designed easily. As an example, a new thirdorder elliptic lowpass filter is realized using only current mirrors and grounded capacitors. PSPICE simulations have been carried out using 0.18 μm CMOS technology. The simulation results that comply with the theoretical analysis are obtained. The circuit has several advantages, such as low voltage（0.9 V）, simple circuit, low filter sensitivities, adjustable cutoff frequency, which is suitable for full integration.

Key words: current mirror (CM), current-mode filters, linear transformation (LT)