imp809 sp809 lm809 复位ic

 the imp809/imp810 are 3.0v, 3.3v and 5.0v power supply supervisor circuits
optimized for low-power microprocessor (μp), microcontroller (μc)
and digital systems. the imp809/810 are improved drop-in replacements
for the maxim max809/810 and feature 60% lower supply current.
a reset signal is issued if the power supply voltage drops below a preset
reset threshold and is asserted for at least 140ms after the supply has
risen above the reset threshold. the imp809 has an active-low reset
output that is guaranteed to be in the correct state for vcc down to 1.1v.
the imp810 has an active-high reset output. the reset comparator is
designed to ignore fast transients on vcc.
low supply current makes the imp809/imp810 ideal for use in portable
and battery operated equipment. the imp809/imp810 are available in a
compact 3-pin sot23 package.
six voltage thresholds are available to support 3v to 5v systems: