Direct Fuel Injection Diver Diagnostic with Complementing Shunt

摘要

The present invention provides a circuit topology and component selection methodology to reduce over-current detection threshold variance and reduce maximum over-current detection threshold for a Direct Injection Fuel System Driver. The system utilizes MOSFET and diode components to steer current through the solenoid load. Injector driver comparators monitor the voltage drop across each MOSFET's drain-source path relative to voltage thresholds. Over-current is detected when the drain-source path voltage drop exceeds the corresponding threshold voltage while the path's MOSFET is switched ON and conducting current. Large tolerance of MOSFET on-stale resistance results in a large variation of overcurrent threshold over the operating temperature range.