The MAX7408/MAX7411/MAX7412/MAX7415 5th-order,
lowpass, elliptic, switched-capacitor filters (SCFs) operate
from a single +5V (MAX7408/MAX7411) or +3V
(MAX7412/MAX7415) supply. The devices draw only
1.2mA of supply current and allow corner frequencies
from 1Hz to 15kHz, making them ideal for low-power
post-DAC filtering and anti-aliasing applications. They
can be put into a low-power mode, reducing supply
current to 0.2?A.
Two clocking options are available: self-clocking (through
the use of an external capacitor) or external clocking for
tighter cutoff-frequency control. An offset-adjust pin
allows for adjustment of the DC output level.
The MAX7408/MAX7412 deliver 53dB of stopband
rejection and a sharp rolloff with a transition ratio of 1.6.
The MAX7411/MAX7415 achieve a sharper rolloff with a
transition ratio of 1.25 while still providing 37dB of stopband
rejection. Their fixed response limits the design
task to selecting a clock frequency.
See also