A3938 isThree-phase brushless DC motor controller。 The A3938's high current gate drive capability allows driving a wide range of power MOSFETs and supports motor supply voltages up to 50 V. The A3938 integrates a bootstrap high-side driver to minimize driving N-channelsMOSFET driversThe number of external components required.
Internal fixed downtime PWM current control circuitry can be used to regulate the maximum load current to the desired value. The peak load current limit can be set by the user by selecting the input reference voltage and an external sense resistor. User-selected external RC timing network sets fixed downtime pulse duration. For additional flexibility, the PWM input provides speed/torque control, where internal current control circuitry sets a limit on the maximum current.
The A3938 has synchronous rectification. This shortens the current path through the power MOSFET reverse diode during PWM aperiodic current decay. This minimizes the power dissipation of the MOSFET, eliminates the need for external power clamping diodes, and provides a more economical option for MOSFET drivers.
The A3938 provides rectification logic for Hall sensor ICs configured with 120 degree pitch. The Hall input pin is pulled up to the endogenous 5 V reference. Power MOSFET protection features include bootstrap capacitor charge current monitoring, regulator undervoltage monitoring, motor pin short to ground, and thermal shutdown.
This LD package is lead (Pb) free with 100% matte tin leadframe plating.
- Drives a variety of N-channel MOSFETs
- Low-end synchronous rectification
- Power MOSFET protection
- Adjustable inductive time for cross-conduction protection
- Selectable free stop or dynamic braking on the power-off or "reset" input
- Fast/slow current attenuation mode
- Internal PWM current control
- Motor pin ground short-circuit protection
- Internal 5 V regulator
- Troubleshooting output
- Thermal shutdown function
- Undervoltage protection