3-Pin Microcontroller Power Supply Supervisor u Embedded controllers u Battery operated systems u Intelligent instruments u Wireless communication systems u PDAs and handheld equipment u Improved Maxim MAX809/MAX810 replacement — Lower supply current…6μA — 80% lower maximum supply current u Monitor 5V, 3.3V and 3V supplies u 140ms min. reset pulse width u Active-low reset valid with 1.1V supply (IMP809) u Small 3-pin SOT-23 package u No external components u Specified over full temperature range — –40°C to 105°C Block Diagrams IMP809 (IMP810) VCC VCC VCC GND GND RESET (RESET) 809/10_01.eps μP RESET Input The IMP809/IMP810 are 3.0V, 3.3V and 5.0V power supply supervisor circuits optimized for low-power microprocessor (μP), microcontroller (μC) and digital systems. The IMP809/810 are improved drop-in replacements for the Maxim MAX809/810 and feature 60% lower supply current. A reset signal is issued if the power supply voltage drops below a preset reset threshold and is asserted for at least 140ms after the supply has risen above the reset threshold. The IMP809 has an active-low RESET output that is guaranteed to be in the correct state for VCC down to 1.1V. The IMP810 has an active-high RESET output. The reset comparator is designed to ignore fast transients on VCC. Low supply current makes the IMP809/IMP810 ideal for use in portable and battery operated equipment. The IMP809/IMP810 are available in a compact 3-pin SOT23 package. Six voltage thresholds are available to support 3V to 5V systems: