Battery Protection IC targets hybrid and electric vehicles.
Press Release Summary:
Designed for high-cell-count Li-Ion battery stacks, 12-channel Model MAX11080 provides redundant cell monitoring to prevent batteries from exploding. Up to 31 units can be daisy-chained together to monitor as many as 372 cells. Capacitor-based interface provides isolation from one bank of batteries to next, eliminating cascading electrical failures. Operating from 6-72 V, stackable fault monitor consumes 80 µA in operating mode and 2 µA in shutdown mode.
Original Press Release:
Battery-Protection IC Reduces BMS Cost by 80% in Hybrid and Electric Vehicles
12-channel battery-protection IC reduces BMS cost up to 80%.
SUNNYVALE, CA-July 22, 2009-Maxim Integrated Products (NASDAQ: MXIM) introduces the MAX11080, a high-voltage, 12-channel battery-protection IC for high-cell-count lithium-ion (Li+) battery stacks. The first stackable fault monitor on the market, this device provides redundant cell monitoring to prevent Li+ batteries from exploding (thermal runaway). Up to 31 MAX11080s can be daisy-chained together to monitor as many as 372 cells. This capability prevents cascading electrical failures and eliminates the expensive isolation components required by discrete solutions. In a typical hybrid car, Maxim's solution reduces the cost of the battery-management system (BMS) by up to 80%.
Offering world-class accuracy, ultra-low power consumption, built-in safety and self-diagnostic features, and plenty of configurability, the MAX11080 solves the problems associated with safely monitoring large battery stacks. It is well suited for a spectrum of battery applications including automotive, industrial, power line, and battery backup.
Clean Energy Trends Are Driving Unprecedented Growth in the Energy Storage Market
From transportation to smart grids, energy storage technologies are critical to enabling the transition from fossil fuels to clean energy. The energy storage market is thus poised for unprecedented growth as green initiatives gain traction among consumers and governments worldwide. Lux Research predicts that the overall energy storage market will grow by 55% to $64 billion in 2012. The transportation energy storage market, meanwhile, will benefit from increasing demand for hybrid electric vehicles (HEVs), growing from $12.9 billion in 2007 to $19.9 billion in 2012.*
Power Lithium-Ion Technologies-An Explosive Market
The fuel tank of the future, HEV battery packs are a critical part of the drive train for next-generation transportation systems.
Though nickel-metal hydride (NiMH) was the battery chemistry of choice in the first HEVs, Li+ batteries are expected to dominate the market by 2015, as they offer a higher energy density and, therefore, longer per-charge driving range. Lux Research predicts that Li+ battery sales will jump from $6.8 billion in 2007 sales to $16.9 billion in 2012.
Yet, Li+ batteries are particularly volatile, requiring careful design and sophisticated monitoring schemes to ensure safe operation. Cell overvoltages can cause a rapid increase in cell temperature, producing a thermal-runaway condition in which gases are vented. Since HEVs often require hundreds of cells in series, the consequences of a failure are substantial: a fault in one cell could cause the entire battery pack to burn or explode.
The Challenge: Bringing Down the Cost of Safety
Today battery pack designers invest a tremendous amount of time and resources to ensure the absolute safety of their stacks. Typical protection circuits employ multiple 3- or 4-channel fault monitors with costly galvanic isolators between the monitors and an assortment of analog and passive components (resistors, multiplexers, etc.). These circuits are bulky and costly, not to mention time intensive.
The MAX11080 greatly simplifies the design of high-cell-count battery packs. A 12-channel fault monitor, this device employs a proprietary capacitor-isolated daisy-chain interface to minimize component count and cost. This unique architecture allows up to 31 devices to be connected in a series stack to monitor as many as 372 cells. Meanwhile, the capacitor-based interface provides extremely low-cost isolation from one bank of batteries to the next, eliminating cascading electrical failures.
Dispatching of the need for costly isolation components, Maxim's solution consumes 75% less space than discrete designs. Altogether, it can reduce the expense of a typical battery-management system from $250 to a mere $50.
The MAX11080 Sets New Performance Benchmarks
Beyond cost savings, Maxim's solution delivers unparalleled performance.
The company's high-voltage, small-geometry BiCMOS process enables the industry's highest voltage tolerance (80V), excellent ESD performance (±2kV, Human Body Model), hot-swap capability, and reliable performance over a wide temperature range. To protect against battery thermal runaway, the MAX11080's ultra-accurate overvoltage detection guarantees less than ±25mV error over the full AEC-Q100 Type 2 temperature range (-40°C to +105°C).
Additionally, the MAX11080 offers a 10x reduction in power consumption (80µA, operating mode) to conserve battery life. A unique built-in shutdown feature reduces consumption to an ultra-low 2µA leakage, allowing the pack to be stored for many years with very little battery drain.
Flexible Features
The MAX11080 has 16 selectable overvoltage thresholds, as well as 8 selectable undervoltage thresholds. The undervoltage-detection feature can be disabled if desired. The device includes a programmable detection-delay feature that allows the user to filter out transient events in the battery pack to eliminate false overvoltage or undervoltage alarms. The alarm line operates using a 4kHz heartbeat signal, the absence of which indicates a valid overvoltage or undervoltage event. These features are critical for discriminating between legitimate and false alarms, preventing the application from shutting down unnecessarily.
Designed for Automotive
The MAX11080 has built-in self-configuration and self-diagnostic modes. On power-up the device automatically detects the presence of batteries and can be configured from 2 to 12 cells in any connection sequence or installation pattern. The device also self tests the internal comparator circuitry to ensure proper functionality on power-up. It is capable of detecting the open or short of any pin on the package and constantly monitors the pins for such a failure. FMEA reports are available upon request for the design and for the package I/Os.
Summary of MAX11080 Features
o 2-cell to 12-cell Li+ battery-fault detection
o Capacitor-isolated daisy-chain interface
- Eliminates costly isolation components
- Allows up to 31 MAX11080s to be connected in series for as many as 372 cells
o Pin-selectable overvoltage threshold from 3.3V to 4.8V in 100mV increments
- ±25mV detection accuracy
o Pin-selectable undervoltage threshold from 1.6V to 2.8V in 200mV increments
- ±100mV detection accuracy
o Ultra-low power consumption
- 80µA in operating mode
- 2µA in shutdown mode
o Operates from 6V to 72V; withstands spikes up to 80V
The MAX11080 is packaged in a 38-pin TSSOP and is fully specified for operation over the -40°C to +105°C temperature range. Prices start at $3.92 (100-up, FOB USA). For more information, please visit: www.maxim-ic.com/MAX11080-Battery.
Maxim Integrated Products is a publicly traded company that designs, manufactures, and sells high-performance semiconductor products. The Company reported revenue in excess of $2 billion for fiscal 2008. Maxim was founded over 25 years ago with the mission to deliver innovative analog and mixed-signal engineering solutions that add value to its customers' products. To date, it has developed over 6000 products serving the industrial, communications, consumer, and computing markets. For more information, go to www.maxim-ic.com.
*Lux Research, "Alternative Power and Energy Storage State of the Market Q2 2008: Making Sense of the Next Big Thing" (May 2008).
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