Single-coil driver simplifies design of 30 W server fans
The MLX90418 from Melexis provides a complete code-free solution for driving a single 30 W fan or dual 15 W fans without the need for an MCU, and supports various server-specific fan functions.
Melexis has released the MLX90418, a complete motor driver IC for single-coil brushless dc (BLDC) fans used in servers.
Today, a single-coil system is the normal choice for server cooling fans rated for up to 15 W. Higher-power fans typically adopt either a single-coil topology controlled by a microcontroller, or a three-phase BLDC motor system.
The MLX90418 now extends the scope of single-coil systems up to 30 W in 4 cm or 6 cm server fans, without the need for software control implemented in an MCU. By using the MLX90418 in a single-coil fan motor, OEMs can reduce bill-of-materials cost by up to 25% compared to existing three-phase BLDC fans. By providing code-free plug-and-play functionality, the MLX90418 also enables the OEM to avoid the need for validation of the software in MCU-based solutions, freeing design engineering resources.
A dedicated solution for server fans, the MLX90418 includes valuable server-specific functions such as ac power loss management. In addition, the power loss braking, handling an 8 A braking current, allows for fast and safe servicing. It also avoids the reduction in thermal efficiency caused by pressure bleeding when a fan malfunctions.
The latest 30 W 4028 single-fan systems offer similar pressure and flow performance as legacy 4056 twin fans of a similar power rating, reducing footprint and system cost.