ISL9208

Description

The ISL9208 is an overcurrent protection device and analog front end for a microcontroller in a multi-cell Li-ion battery pack. The ISL9208 supports battery pack configurations consisting of 5-cells to 7-cells in series and 1 or more cells in parallel. The ISL9208 provides integral overcurrent protection circuitry, short circuit protection, an internal 3.3V voltage regulator, internal cell balancing switches, cell voltage monitor level shifters, and drive circuitry for external FET devices for control of pack charge and discharge. Selectable overcurrent and short circuit thresholds reside in internal RAM registers. An external microcontroller sets the thresholds by setting register values through an I2C serial interface. Internal registers also contain the detection delays for overcurrent and short circuit conditions. Using an internal analog multiplexer the ISL9208 provides monitoring of each cell voltage plus internal and external temperature by a separate microcontroller with an A/D converter. Software on this microcontroller implements all battery pack control functionality, except for overcurrent and short circuit shutdown.