STEVAL-L99MH98

The STEVAL-L99MH98 is a low-cost tool designed to evaluate the L99MH98, a smart power device designed by STMicroelectronics in a VFQFN48L package with an exposed pad. The L99MH98 is an integrated octal half-bridge pre-driver dedicated to controlling up to sixteen N-channel MOSFETs. It is intended for DC motor control applications such as automotive power seat control or other applications.

A 24-bit serial peripheral interface (SPI) is used for configuring and controlling the eight half-bridges or four H-bridges. SPI status registers provide high-level diagnostic information such as supply voltage monitoring, charge pump voltage monitoring, temperature warning, and overtemperature shutdown. Each gate driver independently monitors its external MOSFET drain-source voltage for fault conditions. The L99MH98 supports indirect current measurement on external MOSFETs, allowing cost savings and lower system complexity, avoiding the usage of shunt resistors.

A more efficient gate current control of the external MOSFETs, called “three stages gate current,” decreases and optimizes electromagnetic interference (EMI). Protection features (drain-source monitoring for short circuit detection, overtemperature warning and shutdown, timeout watchdog for MCU control, detailed off-state diagnostic via SPI) ensure the ASIL-B achievement according to the ISO 26262 standard. Thanks to the expansion connectors, the STEVAL-L99MH98 allows the complete control of the L99MH98 communication interface (SPI) and parallel input/output. The evaluation board can also be controlled using a graphical user interface.