A3935
3-Phase Power MOSFET Controller for Automotive Applications
Features and Benefits
Description
▪ 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
TheA3935isdesignedspecificallyforautomotiveapplications
thatrequirehigh-powermotors.Eachprovidessixhigh-current
gatedriveoutputscapableofdrivingawiderangeofN-channel
power MOSFETs.
Arequirement 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.
▪ 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 operation
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▪ Thermal shutdown
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.
Package 36-pin QSOP (LQ):
Diagnostic outputs can be continuously monitored to protect
the driver from short-to-battery, short-to-supply, bridge-open,
andbatteryunder/overvoltageconditions.Additionalprotection
features include dead-time, VDD undervoltage, and thermal
shutdown.
TheA3935issuppliedina36-lead0.8mmpitchQSOP(package
LQ, similar to SOICW).The lead (Pb) free variants (suffix –T)
have 100% matte tin leadframe plating.
Approximate scale 1:1
Typical Application
26301.102J