The MIC809 and MIC810 are inexpensive microprocessor supervisory circuits that monitor power supplies in microprocessor based systems. The function of these devices is to assert a reset if the power supply drops below a designated reset threshold level. Several different reset threshold levels are available to accommodate 3V, 3.3V or 5V powered systems. The MIC809 has an active-low /RESET output, while the MIC810 offers an active-high RESET output. The reset output is guaranteed to remain asserted for a minimum of 140ms after VCC has risen above the designated reset threshold level. Having a push-pull output stage, the MIC809/810 does not require a pull-up resistor at the output. The MIC809/810 comes in a 3-pin SOT-23 and SC-70 package. The MIC809 is also available with a shorter reset timeout (30ms min.). See the MIC809-5. All support documentation can be found on Micrel's web site at www.micrel.com.