The MCF8315A provides a single-chip, code-free sensorless FOC solution for customers driving speed-controlled 12- to 24-V brushless-DC motors requiring up to 4-A peak phase currents.

The MCF8315A integrates three ½-bridges with 40-V absolute maximum capability and a low R_DS(ON) of 240-mΩ (high-side + low-side) to enable high power drive capability. Current is sensed using an integrated current sensing circuit which eliminates the need for external sense resistors. Power management features of an adjustable buck regulator and LDO generate the necessary voltage rails for the device and can also be used to power external circuits.

MCF8315A implements Sensorless FOC, and so an external microcontroller is not required to spin the brushless-DC motor. The algorithm is implemented in a fixed-function state machine, so no coding is needed. The algorithm is highly configurable through register settings ranging from motor start-up behavior to closed loop operation. Register settings can be stored in non-volatile EEPROM, which allows the device to operate stand-alone once it has been configured. The device receives a speed command through a PWM input, analog voltage, frequency input or I²C command.

In-built protection features include power-supply under voltage lockout (UVLO), charge-pump under voltage lockout (CPUV), over current protection (OCP), AVDD under voltage lockout (AVDD_UV), buck regulator UVLO, motor lock detection and over temperature warning and shutdown (OTW and TSD). Fault events are indicated by the nFAULT pin with detailed fault information available in the registers.

The MCF8315A device is available in a 0.5-mm pin pitch, VQFN surface-mount package. The VQFN package size is 7 mm × 5 mm with a height of 1 mm.