IMP1232LP Datasheet, PDF (14/36 Pages) IMP, Inc – 5V μP Power Suppl er Supply Monit y Monitor and or and Reset Cir eset Circuit

IMP1812
Application Information
Operation – Power Monitor
The IMP1812 detects out-of-tolerance power supply conditions. It
resets a processor during power-up, power-down and issues a
reset to the system processor when the monitored power supply
voltage is below the reset threshold. When an out-of-tolerance V_CC
voltage is detected, the RESET signal is asserted. On power-up,
RESET is kept active (HIGH) for approximately 150ms after the
power supply voltage has reached the selected tolerance. This
allows the power supply and microprocessor to stabilize before
RESET is released.
V_CCTP (MIN)
t_R
V_CCTP (MAX)
V_CCTP
V_CC
V_CCTP (MAX)
V_CCTP
t_F
V_CCTP (MIN)
t_RPD
RESET
V_OH
RESET Slews with V_CC
1812_07.eps
Figure 2. Timing Diagram: Power-Down
V_IN
t_RPU
RESET
V_OL
1812_06.eps
Figure 1. Timing Diagram: Power-Up
4
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