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 MAX6730A–MAX6735A µP supervisors are relative-

MAX6730A–MAX6735A, preventing undesirable reset

pulses to the µP. The Typical Operating Characteristics

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)

MAX6731A

MAX6733A

MAX6735A

RESET TO

OTHER

SYSTEM

COMPONENTS

GND

µP

RST

GND

10k

Ω

RESET

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