Method to Extend Shelf Life of Computer Motherboard Battery Using Isolation Circuit
Original Publication Date: 2004-May-28
Included in the Prior Art Database: 2004-May-28
A simple FET load switch circuit is placed between the system board's coin battery and the battery backed-up loads. The P-Channel FET switch is enabled during system board manufacturing by using the Manufacturing Bypass jumper shown in the figure to test the battery backed-up load circuits. The FET load switch disconnects the battery from the load circuits when it's on the "shelf" prior to chassis installation. When the system board is installed in to a system chassis, the mounting screw then re-connects the battery to the circuit.