ACE809N datasheet(6/8 Pages) ACE

6 / 8 page

ACE803N/ACE809N/ACE810N

Ultra Low Power Microprocessor Reset IC

VER 1.2

Ensuring a Valid Reset Output Down to VCC = 0

When VCC falls below 1.15V, the ACE809N RESET output no longer sinks current—it becomes an open

circuit. Therefore, high-impedance CMOS logic inputs connected to RESET can drift to undetermined

voltages. This presents no problem in most applications, since most

μP and other circuitry is inoperative

with VCC below 1.15V. However, in applications where RESET must be valid down to 0V, a pull-down

resistor is needed from RESET pin to GND as shown in Figure 4, then RESET output will be held at low

state. The resistor’s value is not critical, it should be about 100KΩ, large enough not to load RESET, small

enough to pull RESET to ground.

A 100KΩ pull-up resistor to V

CC is also recommended for the ACE810N if active high RESET is required

to remain valid for VCC < 1.15V.

ACE809N

Fig. 3 RESET Valid to Ground Circuit

ACE809N Datasheet(PDF) 6 Page - ACE Technology Co., LTD.