Monolithic Power Systems — MP6540 & MP6540A Driver ICs

The MP6540 and MP6540A driver ICs from Monolithic Power Systems implement the complete power stage of a three-phase, Brushless DC (BLDC) motor.

These motor drivers include three half-bridges composed of six N-channel power MOSFETs, pre-drivers, gate-drive power supplies, and bidirectional current-sense amplifiers.

The two parts are identical except for the provision of inputs: the MP6540 has enable and PWM inputs for each half-bridge, while the MP6540A has separate high- and low-side inputs.

The MP6540 and MP6540A can typically supply up to 10A of peak current for one second, and 3A continuously, and the driver’s maximum power capability depends on thermal conditions and the construction of the board. The devices use an internal charge pump to generate the gate-drive supply for the high-side MOSFETs. A trickle-charge circuit maintains sufficient gate-drive voltage to operate at 100% duty cycle.

Internal safety features include thermal shut-down, under-voltage lock-out, and over-current protection.