EMC FLEX BLOG A site dedicated to Automotive EMC Testing for Electronic Modules

Automotive 12V Battery - Voltage Drops

10. September 2015 12:18 by streng in
Simple simulation of preventing voltage drops issues for 9V to 16V operating voltage

Simple simulation to prevent voltage drop issues for 9V to 16V operating voltage range devices.

All DUT's functions are required to perform as designed during battery voltage drops of up to 1 ms.  For drops above 1 ms the functions are allowed to be temporarily disrupted or fail in a safe mode. Upon return to the operating voltage range the DUT is supposed to auto-recover and resume its operation. In the above example the DUT's functions should not be disrupted (dropout = 1.3 ms, B+ = 9.36 V).

In the above example (dropout = 1.67 ms, B+ = 8.65 V) a fail safe behavior is acceptable. The software will prevent the DUT from resuming its operation as long as B+ is detected below the voltage range. Once B+ line is above 9V the auto recover process should be initiated.