The MCT8315A provides a single-chip, code-free sensorless trapezoidal solution for customers requiring high speed operation (up to 3 kHz electrical speed) or very fast start-up time (< 50ms) for 12- to 24-V brushless-DC motors requiring up to 4-A peak phase currents.

The MCT8315A integrates three ½-bridges with 40-V absolute maximum capability and a low R_DS(ON) of 240-mΩ (high-side + low-side FETs) to enable high power drive capability. Current is sensed using integrated current sensing circuits which eliminate the need for external current sense resistors. Power management features including an output voltage-adjustable buck regulator and 3.3-V LDO generate the necessary voltage rails for the device and can also be used to power external circuits.

Sensorless trapezoidal control 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. MCT8315A allows for a high level of monitoring; variables like duty cycle, motor speed, DC bus power can be displayed and observed as an analog output via two 12-bit DACs. This feature provides an effective method to tune speed loops as well as motor acceleration. The device can receive a speed command through a PWM signal, analog voltage, frequency input or I²C instruction.

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 MCT8315A 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.