A4918: Automotive Three-Phase MOSFET Driver

Description

The A4918 is an N-channel power MOSFET driver capable of controlling MOSFETs connected in a 3-phase bridge arrangement and is specifically designed for automotive applications with high-power inductive loads, such as BLDC motors. A unique charge pump regulator provides the supply for the MOSFET gate drive for battery voltages down to 7 V and allows the A4918 to operate with a reduced gate drive down to 4.5 V. Gate drive voltage and strength are programmable to help reduce EMC issues. A bootstrap capacitor is used to provide the above-battery supply voltage required for N-channel MOSFETs with an additional above-battery charge pump to ensure that the bootstrap capacitors remain charged when held in the on state. Full control is provided over all six power MOSFETs in the 3-phase bridge, allowing motors to be driven with block commutation or sinusoidal excitation.

The power MOSFETs are protected from shoot-through by integrated crossover control and optional programmable dead time. Integrated diagnostics provide indication of multiple internal faults, system faults, and power bridge faults, and can be configured to protect the power MOSFETs under most short circuit conditions. For safety-critical systems, the integrated diagnostic operation can be verified under control of the serial interface. The serial interface is provided to alter programmable settings and read back detailed diagnostic information.

Allegro recommended automotive-qualified Hall latches: APS122x5 and APS122x0

The A4918 is supplied in a 48-lead QFP package with exposed thermal pad as well as a in a new 7x7 48L QFN package with exposed thermal pad (reducing the PCB footprint by ~40%). These packages are lead (Pb) free with 100% matte tin leadframe plating.

ASIL Logo

A4918 was developed in accordance with ISO 26262:2011 as a hardware safety element out of context with ASIL D capability (pending assessment) for use in automotive safety-related systems when integrated and used in the manner prescribed in the applicable safety manual and datasheet.

Top Features

  • 3-phase bridge MOSFET driver
  • Bootstrap gate drive for N-channel MOSFET bridge
  • Cross-conduction protection with adjustable dead time
  • Charge pump for low supply voltage operation
  • Programmable gate drive voltage and strength
  • 4.5 to 50 V supply voltage operating range
  • Integrated logic supply
  • Three programmable current sense amplifiers
  • SPI-compatible serial interface
  • Bridge control by direct logic inputs or serial interface
  • Extensive programmable diagnostics
  • Diagnostic verification
  • Safety assist features
  • Automotive AEC-Q100 qualified

Part Number Specifications and Availability

Part Number Package Type Temperature RoHS
Compliant
Part Composition /
RoHS Data
Comments Samples Check Stock
APEK4918KEV-01-T DEMO BOARD -20°C to 85°C No -- Contact your
local sales rep
Check
Distributor Stock
A4918KEVSR-3-T 48-lead QFN/MLP -40°C to 125°C Yes View Data Contact your
local sales rep
Check
Distributor Stock
A4918KEVSR-5-T 48-lead QFN/MLP -40°C to 125°C Yes View Data Contact your
local sales rep
Check
Distributor Stock
A4918KJPTR-3-T 48-lead LQFP -40°C to 150°C Yes View Data Contact your
local sales rep
Check
Distributor Stock
A4918KJPTR-5-T 48-lead LQFP -40°C to 150°C Yes View Data Contact your
local sales rep
Check
Distributor Stock
APEK4918KJP-01-T DEMO BOARD -40°C to 150°C No -- Contact your
local sales rep
Check
Distributor Stock

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.

Packaging

A4918 Packages