Multi-channel matching in CMOS filters

This paper describes two chips designed respectively for narrow and wide band filter applications in the frequency range 1 kHz-100 kHz. The designs are general purpose, in that the resistor and capacitor values may be adjusted, through mask changes. The filters have been demonstrated on a 1.2 micron foundry CMOS process. A key element of the designs was in provision of channel to channel matching in the three channels per chip designs. This was approached through a modular approach to layout, and Monte Carlo predictions of results based on foundry data spread. An essential requirement in the design was for all, or almost all, components to be on chip, even at the lowest frequencies