The CA3277 is a Dual 5V Voltage Regulator IC intended for microprocessorand logic controller applications. It is supplied with featuresthat are commonly specified for sequentially controlledshutdown and startup requirements of microcontrollers. Over-voltageshutdown, short circuit current limiting and thermal shutdownfeatures are provided for protection in the harsh environmental applicationsof industrial and automotive systems. The CA3277 functionsare complementary to the needs of microcontroller and memory circuits,providing for sustained memory with a 5V standby output.The Ignition Comparator senses the voltage level at the IGN IN inputand provides a 5V logic switched output (supply sourced fromOUT1). The Ignition Output, IGN OUT can be used to signal a systemmicrocontroller which can respond with a logic switched outputto the CA3277 ENABLE input control for OUT2. The OUT1 +5VStandby Supply of the regulator is normally used as a power supplyfor microcontroller/memory circuits to preserve stored data when inthe standby mode.To allow for maximum heat transfer from the chip,the four center leads are directly connected to the die mounting pad.Refer to AN9302 for further information on CA3277 circuit Applications.