IMP809, IMP810
Application Information
Negative V
CC
Transients
The IMP809/810 protect µPs from brownouts and low V
CC
. Short
duration transients of 100mV amplitude and 20µs or less duration
typically do not cause a false RESET.
Valid Reset with V
CC
under 1.1V
To ensure logic inputs connected to the IMP809 RESET pin are in
a known state when V
CC
is under 1.1V, a 100kΩ pull-down
resistor at RESET is needed. The value is not critical. A pull-up
resistor to V
CC
is needed with the IMP810.
VCC
VCC
100kΩ
Power
Supply
IMP809
RESET
GND
100kΩ
Power
Supply
IMP810
RESET
GND
809/10_04.eps
809/10_05.eps
Figure 2. RESET Valid with V
CC
Under 1.1V
Figure 3. RESET Valid with V
CC
Under 1.1V
Bi-directional Reset Pin Interfacing
The IMP809/810 can interface with µP/µC bi-directional reset
pins by connecting a 4.7kΩ resistor in series with the
IMP809/810 reset output and the µP/µC bi-directional reset pin.
BUF
Buffered
RESET
VCC
Power
Supply
IMP809
4.7kΩ
RESET
GND
Bi-directional I/O Pin
(Example: 68HC11)
µC
or
µP
RESET
Input
GND
809/10_06.eps
Figure 4. Bi-directional Reset Pin Interfacing
5
A1PROS [ A1 PROS CO., LTD. ]
