SLVSE39B November 2017 – July 2018 DRV8304
UNLESS OTHERWISE NOTED, this document contains PRODUCTION DATA.
Refer to the PDF data sheet for device specific package drawings
The IDRIVE component implements adjustable gate-drive current to control the MOSFET VDS slew rates. The MOSFET VDS slew rates are a critical factor for optimizing radiated emissions, energy and duration of diode recovery spikes, dV/dt gate turnon leading to shoot-through, and switching voltage transients related to parasitics in the external half-bridge. IDRIVE operates on the principal that the MOSFET VDS slew rates are predominately determined by the rate of gate charge (or gate current) delivered during the MOSFET Qgd or Miller charging region. By allowing the gate driver to adjust the gate current, it can effectively control the slew rate of the external power MOSFETs.
IDRIVE allows the DRV8304 device to dynamically switch between gate drive currents either through a register setting on the SPI device or the IDRIVE pin on hardware interface device. The SPI and hardware devices provide 7 IDRIVE settings ranging from 15-mA to 150-mA source and 30-mA to 300-mA sink. The gate-drive current setting is delivered to the gate during the turnon and turnoff of the external power MOSFET for the tDRIVE duration. After the MOSFET turnon or turnoff, the gate driver switches to a smaller hold current (IHOLD) to improve the gate driver efficiency. Additional details on the IDRIVE settings are described in the Register Maps section for the SPI device and in the Pin Diagrams section for the hardware interface device.