A3922 Datasheet, PDF (1/53 Pages) Allegro MicroSystems – Automotive, Full-Bridge MOSFET Driver

A3922
Automotive, Full-Bridge MOSFET Driver
FEATURES AND BENEFITS
• Full-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
• 5.5 to 50 V supply voltage operating range
• Integrated current sense amplifier
• SPI compatible serial interface
• Bridge control by direct logic inputs or serial interface
• TTL-compatible logic inputs
• Open-load detection
• Extensive programmable diagnostics
• Diagnostic verification
• Safety-assist features
Package: 28-Pin eTSSOP (suffix LP)
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DESCRIPTION
The A3922 is an N-channel power MOSFET driver capable of
controlling MOSFETs connected in a full-bridge (H-bridge)
arrangement and is specifically designed for automotive
applications with high-power inductive loads, such as brush
DC motors solenoids and actuators.
Aunique charge pump regulator provides a programmable gate
drive voltage for battery voltages down to 7 V and allows the
A3922 to operate with a reduced gate drive, down to 5.5 V.
A bootstrap capacitor is used to provide the above-battery
supply voltage required for N-channel MOSFETs.
The full bridge can be controlled by independent logic level
inputs or through the SPI-compatible serial interface. The
external power MOSFETs are protected from shoot-through
by 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.
In addition to providing full access to the bridge control, the
serial interface is also used to alter programmable settings such
as dead time, V_DS threshold, and fault blank time. Detailed
diagnostic information can be read through the serial interface.
The A3922 is supplied in a 28-pin eTSSOP (suffix ‘LP’). This
package is available in lead (Pb) free versions, with 100%
matte-tin leadframe plating (suffix –T).
A3922-DS
VBAT
ECU
A3922
SPI
GND
Typical Application – Functional Block Diagram