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.
The LTC3300-1 from Linear Technology is a high efficiency bidirectional multicell battery balancer for equalizing cell state of charge (SoC) in a series-connected battery stack. With the LTC3300-1, applications such as electric vehicles (EVs), plug-in hybrid EVs and large energy storage systems using cells with mismatched capacities are no longer limited by the lowest capacity cell in the stack.
This active balancer goes beyond purely dissipative passive balancing solutions, enhancing battery performance by efficiently transferring charge to or from adjacent cells in order to bring mismatched cells into SoC balance within the stack. By redistributing charge throughout the stack, the LTC3300-1 compensates for lost capacity due to the weakest cells, enabling faster charging and extending the run time and usable lifetime of the battery stack.
The LTC3300-1 is a key component in a high performance battery management system (BMS) for series-connected Li-Ion or LiFePO4 batteries. The device operates as a fault-protected controller IC for transformer-based bidirectional active balancing. The part utilizes a non-isolated bidirectional synchronous flyback topology to balance up to 6 series-connected cells. Charge can be transferred between a selected cell and 12 or more adjacent cells.
All balancers can operate independently and simultaneously with charge/discharge currents up to 10A. Bidirectional operation and simultaneous balancing minimizes the time required to equalize stack SoC, and the parts’ high transfer efficiency (up to 92%) enables high current balancing with minimal power dissipation.
Control of each balancer is provided via a unique level-shifting SPI-compatible serial interface which enables multiple LTC3300-1 devices to be connected in series, without optocouplers or isolators. The part’s stackable architecture together with interleaved transformer connections enable efficient balancing of every cell in an arbitrarily tall string (>1000V) of series-connected batteries. All associated gate drive circuitry, precision current sensing, fault protection circuitry and a robust serial data interface with built-in watchdog timer and cyclic redundancy check (CRC) data error checking are integrated.
The LTC3300-1 is offered in thermally enhanced surface-mount compatible packages: a low profile (0.75mm) 48-lead 7mm x 7mm QFN and a 48-pin 7mm x 7mm LQFP package. The I-grade is specified for both packages, with operating junction temperature range of -40°C to +125°C. Devices are available from stock and 1,000-piece pricing starts at $5.95.
For more information on the LTC3300-1, visit www.linear.com/product/LTC3300-1.
Summary of Features of the LTC3300-1:
- Bidirectional Synchronous Flyback Balancing of up to 6 Li-Ion or LiFePO4 Cells in Series
- Up to 10A Balancing Current (Set by External Components)
- Bidirectional Architecture Minimizes Balancing Time & Power Dissipation
- Up to 92% Charge Transfer Efficiency
- Stackable Architecture Enables >1000V Systems
- Uses Simple 2-Winding Transformers
- 1MHz Daisy-Chainable Serial Interface with 4-Bit CRC Packet Error Checking
- High Noise Margin Serial Communication
- Numerous Fault Protection Features
- 48-Lead 7mm x 7mm Exposed Pad QFN & LQFP Packages
Typical Application
Applications
- Electric Vehicles/Plug-in HEVs
- High Power UPS/Grid Energy Storage Systems
- General Purpose Multicell Battery Stacks
About Linear Technology
Linear Technology Corporation, a manufacturer of high performance linear integrated circuits, was founded in 1981, became a public company in 1986 and joined the S&P 500 index of major public companies in 2000. Linear Technology products include high performance amplifiers, comparators, voltage references, monolithic filters, linear regulators, DC-DC converters, battery chargers, data converters, communications interface circuits, RF signal conditioning circuits, µModule products, and many other analog functions. Applications for Linear Technology’s high performance circuits include telecommunications, cellular telephones, networking products such as optical switches, notebook and desktop computers, computer peripherals, video/multimedia, industrial instrumentation, security monitoring devices, high-end consumer products such as digital cameras and MP3 players, complex medical devices, automotive electronics, factory automation, process control, and military and space systems.
Linear Technology (UK) Limited
Tel: +44 (0)1628 477066
E-mail: uksales@linear.com
Web site: www.linear.com
Website for product information: http://www.linear.com/product/LTC3300-1
