A4939 Datasheet, PDF (1/20 Pages) Allegro MicroSystems – Automotive Three Phase MOSFET Driver

A4939
Automotive Three Phase MOSFET Driver
Features and Benefits
• High current 3-phase gate drive for N-channel MOSFETs
• Cross-conduction protection
• 5.5 to 50 V supply voltage range
• Regulated logic supply voltage output option
• Motor phase short to supply and short to ground detection
• Undervoltage, overtemperature monitors
• Low current Sleep mode option
Applications
• Electronic power steering (EPS, EHPS, EAS)
• Hydraulic pumps
• Engine cooling fan
• Gearbox actuator
Package: 28-pin TSSOP with exposed
thermal pad (suffix LP)
Not to scale
Description
The A4939 is a three-phase controller for use with N-channel
external power MOSFETs and is specifically designed for
automotive applications.
A unique charge pump regulator provides full (>10 V) gate
drive at battery voltages down to 7 V and allows the A4939
to operate with reduced gate drive at battery voltages down
to 5.5 V. A bootstrap capacitor is used to provide the above
battery supply voltage required for N-channel MOSFETs.
One logic level input is provided for each of the six power
MOSFETs in the 3-phase bridge, allowing motors to be driven
with any commutation scheme defined by an external controller.
The power MOSFETs are protected from cross-conduction by
integrated crossover control.
Motor phase short-to-supply and short-to-ground detection
is provided by independent drain-source voltage monitors on
each MOSFET. Short faults, supply undervoltage, and chip
overtemperature conditions are indicated by a single open
drain fault output.
Product variants incorporating a low drop out (LDO) regulator
to source either 5.0 V or 3.3 V to external circuitry are available.
The A4939 is supplied in a 28-pin TSSOP power package with
an exposed thermal pad (package type LP). This package is lead
(Pb) free, with 100% matte-tin leadframe plating (suffix T).
Typical Application Diagram
VDD
VBAT
Micro-
controller
A4939
3-Phase
BLDC
Motor
A4939-DS, Rev. 1