The invention discloses a reconfigurable
filter design method based on a
numerical control adjustable zero point technology, an MOS switch array is directly driven by using a
digital control signal, an external DAC is not needed to generate an
analog control voltage, the problems that an analog circuit is complex, the precision is limited and the
system size is increased are avoided, a
mode switching module adopts a programmable multi-switch structure, and the design efficiency is improved. By changing the connection mode of the high-pass filter and the reconfigurable low-pass filter, flexible switching among all-pass, low-pass, high-pass and band-pass
modes can be realized, and various filtering functions can be completed by a
single chip. The whole filter structure is realized based on a standard
CMOS (Complementary
Metal-
Oxide-
Semiconductor Transistor) process, an external
transmission line or a variable
capacitance element is not needed, the area occupation and the parasitic effect under a low-
frequency band are reduced, the
system integration level and the
reconfigurability are remarkably improved, and the filter realizes the effects of small size, simple control, stable
frequency response and easy integration; the defects that in the prior art, the size is large, DAC control is relied on, and
frequency band application is limited by a
transmission line structure are comprehensively overcome.