3-Pin Microprocessor Reset Circuits
The ACE809 microprocessor supervisory circuits can be used to monitor the power supplies in
microprocessor and digital systems. They provide s reset to the microprocessor during power-up,
power-down and brown-out conditions.
The function of the ACE809 is to monitor the VCC supply voltage, and assert a reset signal whenever this
voltage declines below the factory-programmed reset threshold. The reset signal remains asserted for
240ms after VCC rises above the threshold. The ACE809 has an active-low RESET output. The output of
the ACE809 is guaranteed valid down to VCC =1V. The device is available in a SOT-23-3L package.
The ACE809 is optimized to reject fast transient glitches on the VCC line. Low supply current of 25µA,
(VCC=3.3V) makes these devices suitable for battery powered applications.
• Precision Vcc Monitor for 3.0V,3.3V and 5.0V Supplies
• 140ms Guaranteed Minimum RESET Output Duration
• RESET Output Guaranteed to Vcc=1.0V
• Low 25μA Supply Current.
• Vcc Transient Immunity.
• No External Components.
• Embedded systems
• Critical μP Power Supply Monitoring
• Battery Powered equipment
Absolute Maximum Ratings
Symbol Max Unit
VCC 5.5 V
RESET -0.3 to (Vcc+0.3) V
IOUT 20 mA
PD Internally Limited
Thermal resistance junction to ambient
Operating junction temperature range TJ
0 to 125
Storage temperature range
-60 to 150 ℃
Note 1: Exceeding these rating could cause damage to the device. All voltages are with respect to Ground. Currents are positive
into, negative out of the specified terminal.
Note 2: Voltage values are with respect to the anode terminal unless otherwise noted.
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