SLVSD19A June 2015 – July 2015 DRV8881
PRODUCTION DATA.
An analog current limit circuit on each FET limits the current through the FET by removing the gate drive. If this analog current limit persists for longer than tOCP, all FETs in the H-bridge will be disabled and nFAULT will be driven low. In addition to this FET current limit, an overcurrent condition is also detected if the voltage at xISEN exceeds VOCP.
For the DRV8881E (PH/EN), both H-bridges are shut down when either bridge encounters an overcurrent fault. For the DRV8881P (PWM), only the H-bridge driver experiencing the overcurrent fault is shut down, and the other bridge will remain active.
The driver will be re-enabled after the OCP retry period (tRETRY) has passed. nFAULT becomes high again after the retry time. If the fault condition is still present, the cycle repeats. If the fault is no longer present, normal operation resumes and nFAULT remains deasserted.