MC33345

The MC33345 has the following features including Independently Programmable Charge and Discharge Limits for Both Voltage and Current;Charge and Discharge Current Limit Detection with Delayed Shutdown;Cell Voltage Balancing;On-Chip Balancing Resistors;Virtually Zero Current Sleepmode State when Cells are Discharged;Charge Pump for Reduced Losses with a Low Cell Voltage Battery Pack;Programmable for One, Two, Three or Four Cell Applications;Minimum External Components for Inclusion within the Battery Pack;Available in Low Profile Surface Mount Packages.

The MC33345 is a monolithic lithium battery protection circuit that is designed to enhance the useful operating life of one to four cell rechargeable battery packs.  Cell protection features consist of independently programmable charge and discharge limits for both voltage and current with a delayed current shutdown, cell voltage balancing with on-chip balancing resistors, and a virtually zero current sleepmode state when the cells are discharged. Additional features include an on-chip charge pump for reduced MOSFET losses while charging or discharging a low cell voltage battery pack, and the programmability for a one to four cell battery pack. This protection circuit requires a minimum number of external components and is targeted for inclusion within the battery pack. The MC33345 is available in standard and low profile 20 lead surface mount packages.

Rechargeable lithium-based cells require precise charge and discharge termination limits for both voltage and current in order to maximize cell capacity, cycle life, and to protect the end user from a catastrophic event. The termination limits are not as well defined as with older non-lithium chemistries.These limits are dependent upon a manufacturer's particular lithium  chemistry,  construction technique,  and  intended application. Battery pack assemblers may also choose to enhance cell capacity at the expense of cycle life. In order to address these requirements the MC33345 was developed.MC33345 features programmable voltage and current limits, cell voltage balancing, low operating current, a virtually zero current sleepmode state, and requires few external components to implement a complete one to four cell smart battery pack.