26301.102J
Description
The A3935 is designed specifically for automotive applications
that require high-power motors. Each provides six high-current
gate drive outputs capable of driving a wide range of N-channel
power MOSFETs.
A requirement of automotive systems is steady operation over
a varying battery input range. The A3935 integrates a pulse-
frequency modulated boost converter to create a constant
supply voltage for driving the external MOSFETs. Bootstrap
capacitors are utilized to provide the above battery supply
voltage required for N-channel FETs.
Direct control of each gate output is possible via six TTL-
compatible inputs. A differential amplifier is integrated to
allow accurate measurement of the current in the three-phase
bridge.
Diagnostic outputs can be continuously monitored to protect
the driver from short-to-battery, short-to-supply, bridge-open,
and battery under/overvoltage conditions. Additional protection
features include dead-time, VDD undervoltage, and thermal
shutdown.
The A3935 is supplied in a 36-lead 0.8 mm pitch QSOP (package
LQ, similar to SOICW). The lead (Pb) free variants (suffix –T )
have 100% matte tin leadframe plating.
Features and Benefits
▪ Drives wide range of N-channel MOSFETs in 3-phase bridges
▪ PFM boost converter for use with low-voltage battery supplies
▪ Internal LDO regulator for gate-driver supply
▪ Bootstrap circuits for high-side gate drivers
▪ Current monitor output
▪ Adjustable battery overvoltage detection
▪ Diagnostic outputs
▪ Motor lead short-to-battery, short-to-ground, and bridge-
open protection
▪ Undervoltage protection
▪ –40°C to 150°C T
J
operation
▪ Thermal shutdown
3-Phase Power MOSFET Controller for Automotive Applications
Package 36-pin QSOP (LQ):
Typical Application
Approximate scale 1:1
A3935
