Note: the bq78PL114 is not available anymore and is replaced by the BQ34Z100.
With the Li-Ion battery controller bq78PL114 from Texas Instruments, an advanced battery management system (BMS) can be built. The bq78PL114 is designed for driving high-side p-channel MOSFETs. Preferred however are n-channel MOSFETs, because of the lower on-resistance. N-channel MOSFETs on the high-side however require a gate voltage above the positive rail. Here we need so called high-side n-channel MOSFET driver, which contains a charge pump. There are several of these ICs available, but none of them are suitable for a maximum voltage of 75V, which was necessary for a particular application.
The LM5050-1 is a high side OR-ing FET controller for voltages up to 75V. I have developed a high-side n-channel MOSFET driver for battery management systems with the LM5050-1. Here, this IC has to be used in another way than it is designed for. The circuit is simulated with Multisim but it turned out that the LM5050-1 spice file and the datasheet is not completely correct. So I have further developed the circuit on a breadboard.
Download here the LM5050-1 datasheet.