Cummins Inc.
Low drop real-time-clock battery voltage control circuit for application specific integrated circuit in an engine control module

Abstract:

Systems and apparatuses include a control circuit and a switching circuit. The control circuit is structured to communicate with a real-time-clock battery and to selectively communicate with a vehicle battery. The control circuit is structured in an OFF arrangement when a wake supply voltage is received from the vehicle battery and in an ON arrangement when no wake supply voltage is received. The switching circuit is structured to provide communication between the real-time-clock battery and a real-time-clock power pin of a controller with a voltage drop of about 0.1 volts or less when the control circuit is in the ON arrangement and to inhibit communication between the real-time-clock battery and the real-time-clock power pin when the control circuit is in the OFF arrangement.