TCM809/TCM810

DS21661C-page 6

 2004 Microchip Technology Inc.

3.3

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 k

Ω resistor in series with the output of the TCM809/

TCM810 (Figure 3-3). 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.

FIGURE 3-3:

Interfacing the TCM809 to a

Bidirectional RESET I/O.

TCM809

V

DD

RESET

GND

RESET

GND

Buffered RESET

To Other System

Components

Micro-

4.7 k

Ω

controller

Buffer