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 gate drive current strength, IDRIVE, is selected based on the gate-to-drain charge of the external MOSFETs and the target rise and fall times at the outputs. If IDRIVE is selected to be too low for a given MOSFET, then the MOSFET may not turn on completely within the tDRIVE time and a gate drive fault may be asserted. Additionally, slow rise and fall times will lead to higher switching power losses. TI recommends adjusting these values in system with the required external MOSFETs and motor to determine the best possible setting for any application.
The IDRIVEP and IDRIVEN current for both the low-side and high-side MOSFETs are independently adjustable on the SPI device through the SPI registers. On hardware interface devices, both source and sink settings are selected simultaneously on the IDRIVE pin.
For MOSFETs with a known gate-to-drain charge (Qgd), desired rise time (tr), and a desired fall time (tf), use Equation 7 and Equation 8 to calculate the value of IDRIVEP and IDRIVEN (respectively).