The A3946 is designed specifically for applications that require high power unidirectional DC motors, three-phase brushless DC motors, or other inductive loads. The A3946 provides two high-current gate drive outputs that are capable of driving a wide range of power N-channel MOSFETs. The high-side gate driver switches an N-channel MOSFET that controls current to the load, while the low-side gate driver switches an N-channel MOSFET as a synchronous rectifier.
A bootstrap capacitor provides the above-battery supply voltage required for N-channel MOSFETs. An internal top-off charge pump for the high side allows DC (100% duty cycle) operation of the half-bridge.
The A3946 is available in a choice of two power pack ages: a 16-lead SOIC with two internally-fused pins for enhanced power dissipation (part number suffix LB), and a 16-lead TSSOP with exposed thermal pad (suffix LP). Both packages have a lead (Pb) free version, with 100% matte tin plated leadframes (suffix -T).
Allegro’s products are not to be used in any devices or systems, including but not limited to life support devices or systems, in which a failure of Allegro’s product can reasonably be expected to cause bodily harm.