Allegro MicroSystems Inc. (Worcester, MA) announced the release of the A3940, a new power MOSFET pre-driver IC for large brush dc motors. Targeted at the automotive and industrial markets, the A3940 provides four high-current, gate-drive outputs capable of driving a wide range of power n-channel MOSFETs. Protection features include supply under-voltage and over-voltage, programmable dead time adjustment for cross-conduction protection, thermal shutdown, and motor lead short-to-supply and short-to-ground protection.
Bootstrap capacitors are utilized to provide the above-battery supply voltage required for n-channel FETs. An internal charge pump for the high side will allow for dc (100% duty cycle) operation of the bridge. PHASE and ENABLE input terminals are provided for use in controlling the speed and direction of a dc motor with externally applied pulse-width modulated control signals.
The A3940 is manufactured using Allegro’s ABCD3 (Allegro bipolar CMOS DMOS 3rd-generation) process, and is supplied in either a 28-lead, TSSOP, thermally enhanced package or in a standard 28-lead, SOIC package. The A3940 has an eight-week lead time and is priced at $2.46 per part for quantities of 1,000.