SLLSFU1A December 2023 – July 2024 MCF8315C
PRODMIX
Dead time is inserted between the switching instants of high-side and low-side MOSFETs in a half-bridge leg to avoid shoot-through conditions. Due to dead time insertion, the expected voltage and applied voltage at the phase node differ based on the phase current direction. The phase node voltage distortion introduces undesired distortion in the phase current causing audible noise. MCF8315C integrates a proprietary dead time compensation technique to remove this phase current distortion and greatly reduce the audible noise, thereby significantly improving the acoustic performance of the FOC in MCF8315C. This dead time compensation can be enabled or disabled by configuring DEADTIME_COMP_EN. Even when DEADTIME_COMP_EN is set to 1b (compensation enabled), dead time compensation is disabled when the motor electrical frequency exceeds 135Hz and re-enabled when the motor electrical frequency drops below 127Hz.