CAT853TTBI-T3 Datasheet, PDF (6/9 Pages) ON Semiconductor – 3-Pin Microprocessor Power Supply Supervisors

CAT853, CAT859, CAT863, CAT869
Bi−directional Reset Pin Interfacing
The CAT859 and CAT869 can interface with mP/mC bi−directional reset pins by connecting a 4.7 kW resistor in series with
the CAT859 and CAT869 reset output and the mP/mC bi−directional reset pin.
Power
Supply
BUF
Buffered
RESET
V_CC
CAT8x9
RESET
4.7 kW
V_CC
mP
RESET
INPUT
GND
Bi−directional
I/O Pin
GND
(For example:
68HC11)
Figure 9. Bi−directional Reset Pin Interfacing
CAT853 and CAT863 Open−Drain RESET Application
The CAT853 and CAT863 features an open−drain RESET
output and therefore need a pull−up resistor on the output for
proper operation, as shown on Figure 10. An advantage of
the open−drain output includes the ability to “wire AND”
several outputs together to form an inexpensive logic circuit.
It is also possible to have the pull−up resistor connected to
a different supply which can be higher than the CAT8x3 V_CC
pin. The value of the pull−up resistor is not critical in most
applications, typical values being between 5 kW and 10 kW.
Power
Supply
V_CC
CAT8x3
RESET
GND
5 kW
V_CC
mP
RESET
INPUT
GND
Figure 10. Typical CAT8x3 Open−Drain Circuit Configuration
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