The LTC3871 is available in a thermally enhanced 48-lead LQFP package. Three temperature grades are available, with operation from –40°C to 125°C for the extended and industrial grades and a high temp automotive range of –40°C to 150°C. Figure 1 below shows its typical applications schematic. The P-Channel MOSFET shown at the top of the schematic is for over current and short circuit protection.
The electronically controlled ISG replaces both the conventional starter and alternator with a single electric device for the following reasons:
- To eliminate the starter which is only a passive component during engine operation
- Replaces the present belt and pulley coupling between the alternator and the crankshaft
- To provide fast control of the generator voltage during load dumps
- To eliminate the slip rings and the brushes in some present wound rotor alternators