Applications Information

Interfacing to µPs with Bidirectional

Reset Pins

Microprocessors with bidirectional reset pins can inter-

face directly with the open-drain RST output options.

However, conditions might occur in which the push-pull

output versions experience logic contention with the

bidirectional reset pin of the µP. Connect a 10k

Ω resis-

tor between RST and the µP’s reset I/O port to prevent

logic contention (Figure 5).

The MAX6730–MAX6735 µP supervisors are relatively

MAX6730–MAX6735, preventing undesirable reset

pulses to the µP. The

Typical Operating Characteristics

show Maximum Transient Duration vs. Reset Threshold

Single-/Dual-/Triple-Voltage µP Supervisory

Circuits with Independent Watchdog Output

______________________________________________________________________________________

11

(MIN)

RSTIN

RST

WDO

WDI

MR

Figure 4. Watchdog Input/Output Timing Diagram (MR and WDO Connected)

MAX6731

MAX6733

MAX6735

RESET TO

OTHER

SYSTEM

COMPONENTS

GND

µP

RST

GND

10k

Ω

RESET

Figure 5. Interfacing to µPs with Bidirectional Reset I/O