Features
- 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 TJ operation
- Thermal shutdown
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.
Functional Block Diagram
