TCM809_05 Datasheet, PDF (6/16 Pages) Microchip Technology – 3-Pin Microcontroller Reset Monitors

TCM809/TCM810
4.3 Controllers and Processors With
Bidirectional I/O Pins
Some microcontrollers have bidirectional reset pins.
Depending on the current drive capability of the control-
ler pin, an indeterminate logic level may result if there
is a logic conflict. This can be avoided by adding a
4.7 kΩ resistor in series with the output of the TCM809/
TCM810 (Figure 4-3). If there are other components in
the system that require a reset signal, they should be
buffered so as not to load the reset line. If the other
components are required to follow the reset I/O of the
microcontroller, the buffer should be connected as
shown with the solid line.
Buffer
Buffered RESET
To Other System
Components
V_DD
TCM809
RESET
4.7 kΩ
PICmicro^®
Micro-
controller
RESET
GND
GND
FIGURE 4-3:
Interfacing the TCM809 to a
Bidirectional RESET I/O.
DS21661D-page 6
© 2005 Microchip Technology Inc.