A DESIGN FRAMEWORK FOR LOW-POWER ANALOG FILTER BANKS

We detail the design of multiresolution analog filter banks, linear mo dels of cochlear function, with power dissipation being a prime engine ering constraint, We propose that a reasonable goodness criterion is t he information rate through the system, per watt of power dissipated. Speech applications requiring filter banks with a wide frequency tunin g range, from 20 Hz to 20 kHz, and low power consumption make the tran sconductance-C integrator in subthreshold CMOS the preferable integrat or structure. As a way of example, the dynamic range of a lowpass filt er is computed and subsequently used to design a filter bank that mode ls faithfully cochlear micro-mechanics. The power consumption of the e ntire filter bank is computed from analytical expressions and is estim ated as 355 nW, at 68 kb/s overall information rate at the output of t he system.