A 4th-order 100μA diode-C-based filter with 5dBm-IIP3 at the 24MHz cut-off frequency

Abstract

This paper presents a 4th-order low-pass continuous-time filter with 24MHz bandwidth. Using cross-coupled MOS transistors combined with capacitors and resistors, this architecture synthesizes two complex-conjugate-poles pairs. The filter is designed and optimized to feature high-linearity along all filter passband, and, in particular, at the cut-off frequency edge. The filter consumes 100μA with 1.8V voltage supply, and achieves 45μW/pole power consumption, 150μVRMS input-referred noise, 16dBm IIP3 with 2-3MHz input tones and 5dBm IIP3 near the cut frequency.