ACE803ND

3-Pin Microprocessor Reset Circuits

VER 1.1

6

Interfacing to μPs with Bidirectional Reset Pins

Since the RESET output on the ACE803ND

directly to the microcontroller’s (μC’s) RESET pin with a single pull-up resistor allows either device to

assert reset (Figure 2)

ACE803ND Open-Drain RESET Output Allows Use with Multiple Supplies

Benefits of Highly Accurate Reset Threshold

Most µP supervisor circuits have reset threshold voltages between 5% and 10% below the value of

nominal supply voltages. This ensures a reset will not occur within 5% of the nominal supply, but will occur

when the supply is 10% below nominal.

When using ICs rated at only the nominal supply ±5%, this leaves a zone of uncertainty where the supply

is between 5% and 10% low, and where the reset may or may not be asserted.

The ACE803NDL/M/Z use highly accurate circuitry to ensure that reset is asserted close to the 5% limit,

and long before the supply has declined to 10% below nominal.

Figure 2. Interfacing to μPs with Bidirectional Reset I/O

Supplies