A new design approach of current-mode ( CM) filters is presented. The proposed method is based on simulating the RLC ladder networks using coupled-biquad structures. The loop and branch currents are used as variables to generate coupled-biquad transfer functions that are realized by CM circuits implementing OTAs with multiple outputs. Design of low-pass, band-pass, and high-pass filters with all-pole and elliptic responses are presented. The resulting CM structures only use grounded capacitors making it suitable for VLSI. To illustrate this approach, the implementation of a OTA-based 5th-order all-pole low-pass current-mode filter is designed and simulated in HSPICE.
展开▼
