Power down circuit for data protection in a microprocessor-based system

摘要: An apparatus for use in a stand alone microcomputer controlled system having digital memory device and microprocessor unit includes small battery supply circuitry sensing the power applied at terminals of to control initial application failure manner prevent loss volatile data. The requirements off or standby mode are approximately 1000 times less than operating thereby permit data be stored random access substantial time independent power. monitoring detecting levels, switching power, disabling microprocessor, restarting once has been restored. Specifically, comprises first second comparators coupled cascade, one which senses voltage level other acting as portion switch device, timing capacitors diodes decoupling from backup supply.