Features
- On-chip charge pump for 7 V minimum input supply voltage
- High-current gate drive for driving a wide range of N-channel MOSFETs
- Bootstrapped gate drive with charge pump for 100% duty cycle
- Overtemperature protection
- Undervoltage protection
- -40°C to 135°C ambient operation
Description
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).
Functional Block Diagram
