The LTC3300-1 is a fault-protected controller IC for transformer-based bidirectional active balancing of multicell battery stacks. All associated gate drive circuitry, precision current sensing, fault detection circuitry and a robust serial interface with built-in watchdog timer are integrated.Each LTC3300-1 can balance up to 6 series-connected battery cells with an input common mode voltage up to 36V. Charge from any selected cell can be transferred at high efficiency to or from 12 or more adjacent cells. A unique level-shifting SPI-compatible serial interface enables multiple LTC3300-1 devices to be connected in series, without opto-couplers or isolators, allowing for balancing of every cell in a long string of series-connected batteries.When multiple LTC3300-1 devices are connected in series they can operate simultaneously, permitting all cells in the stack to be balanced concurrently and independently. Fault protection features include readback capability, cyclic redundancy check (CRC) error detection, maximum on-time volt-second clamps, and overvoltage shutoffs.FeaturesLTC3300-1SPI-compatible serial interface in which each chip in the stack communicates bidirectionally to the chips of the same type above and below it via currents. There is no limit to the stack height. Large common mode voltage differences are handled by each LTC3300-1. The microprocessor in the BMS system communicates ONLY with the bottom chip in the stack and subsequently all of the chips use the same fixed internal address.LTC3300-2SPI-compatible serial interface in which each chip has a unique 5-bit pin-strapped address. The microprocessor in the BMS system communicates directly with every chip in the stack with common mode voltage differences handled by digital isolators or opto-couplers. Because of the 5-bit address, the stack height is limited to 32 LTC3300-2 ICs or 192 cells (~800V). There are 5 pins which have a different assignment, all of them serial interface related.ApplicationsElectric Vehicles/Plug-in HEVsHigh Power UPS/Grid Energy Storage SystemsGeneral Purpose Multicell Battery Stacks