#mosfetdriver

The Allegro A4915 Three-Phase MOSFET Driver’s innovative speed input and fully integrated block commutation delivers simple speed control of a BLDC motor with a single analog voltage. Presented by Dan Jacques, Strategic Marketing Manager, Motor Driver ICs.

For our sixth discussion, we will be having Allegro's A4915: 3-phase MOSFET driver. But before we proceed, let us do some recap. First, we had Mouser's Micro-ElectroMechanical Systems. MEMS include accelerometers, gyros, inertial modules, and others alike. Second, we had IXYS' power electronics which drives various parts of heavy lifting machines. Third, we had IXYS' ultra-fast laser diode driver, the IXLD02. It is an ultra high-speed differential laser diode driver designed specifically to drive single junction laser diodes. Then, we discussed why Coilcraft Inductors' voltage ratings are not specified on datasheets. Lastly, we had Microchip's development platform with 2D multi-touch and 3D gestures. Allegro's A4915 is designed for PWM current control of 3-phase brushless DC motors. It is capable of high current gate drive for 6 all N-channel power MOSFETs. An internal charge pump ensures gate drive down to 7 V supply and provides limited gate drive down to 5 V. A bootstrap capacitor is used to generate a supply voltage greater than the source voltage of the high side MOSFET, required for N-channel MOSFETs.

Internal synchronous rectification control circuitry is provided to improve power dissipation in the external MOSFETs during PWM operation. Internal circuit protection includes latched thermal shutdown, dead time protection, and undervoltage lockout. Special power up sequencing is not required.