Atmel Announces First Fully-Configurable Single-Chip Smart Battery Solution

Lithium Ion (Li-ion) is the battery chemistry of choice for high-end portable applications such as laptop PCs, cell phones and digital cameras, due to its high energy per weight and volume ratio, combined with a high load current. A Li-ion based battery control system must control the chemical reaction and protect the system from harmful environmental conditions. Furthermore, the end-user expects the battery control system to deliver a reliable and accurate estimate of charge left. Atmel's ATmega406 single-chip smart battery device is the only product with everything needed to meet these challenges with highest accuracy and reliability at the lowest system cost.

To enable the ATmega406 to be powered directly from a 2-, 3- or 4-cell Li- ion configuration, the device includes an on-chip voltage regulator allowing the device to be powered from 4 - 25V. It also features three 25V-tolerant FET drivers for charge, discharge, and pre-charge, as well as on-chip FETs for cell balancing. To provide the most accurate estimate of charge left, the device has a Coulomb Counter ADC with an 18-bit output for battery current monitoring as well as a 12-bit ADC for individual cell voltage and temperature monitoring. Both ADCs use high-accuracy on-chip voltage reference. Battery protection is autonomous, providing the end-user with the best safety, as MCU- related issues such as a code runaway or a software bug do not affect it. Adding communication periphery and an efficient MCU architecture, ATmega406 is the first fully configurable single-chip smart battery solution in the market.

"The ATmega406 is a result of Atmel's smart battery R&D program since early 2001," said Morten Reintz, Marketing Manager for Atmel's Smart Battery technology. "Long-term development in cooperation with battery manufacturers has resulted in this device integrating all battery management features on one chip. Additionally, this second generation smart battery chip from Atmel enables battery manufacturers to get longer battery life and significantly more accurate estimate of charge left at a lower cost than earlier solutions.

Battery protection is implemented as independent circuitry, not requiring the MCU to operate. If the device is exposed to an over-current or short- circuit condition, the autonomous battery protection will shut off the affected FET. Likewise, if any cell voltage drops to a potentially damaging voltage level, ATmega406 will automatically prevent further battery discharge by shutting down the discharge FET and going to a power-off mode. Independent battery protection ensures the safest solution for the end user. The trigger levels for the different battery protection modes are programmable, and for safety reasons they are also lockable against software updates. If no battery protection is triggered, the MCU is allowed direct FET control, which enables battery- charging algorithms to be implemented inside the battery itself.

A reliable estimate of charge left can be used to extend battery life by allowing the battery to use all its power. The ATmega406's Coulomb Counter and Voltage ADC are custom made for optimal current and voltage tracking, essential for an accurate and reliable estimate of charge left. The current resolution of the Coulomb Counter over the recommended 5 mOhm sense resistor is 0.67 mA, allowing measurements of more than +/-30A. Both ADCs benefit from a very accurate internal voltage reference, with less than +/-0.1% error over temperature after calibration.

Balancing cell voltages effectively increases the amount of charge that can be drawn from the battery pack by aligning the lowest safe voltage of all battery cells. Individual battery cell monitoring combined with the ATmega406's integrated cell balancing FETs allow cell- balancing algorithms implemented in software to improve battery capacity.

With 40 Kbytes of Flash program memory, 512 Bytes of EEPROM for data parameter storage, and 2 Kbytes of internal SRAM for program data, ATmega406 packs the algorithm processing power necessary to implement battery monitoring and management for a full 4-cell laptop PC battery pack configuration. The device includes the SM-bus interface for communication with the host application, and Atmel's self-programming Flash allows battery firmware upgrading through this or any other interface, providing the most flexible design solution in the market.

All parts of the ATmega406 are optimized for extremely low power consumption, drawing less than 1.2 mA in active mode and less than 2 uA in power-off mode.

A full suite of development tools supports ATmega406, including the JTAGICE mkII emulator, and a smart battery development kit. The ATmega406 is available today in LQFP 48-pin package and pricing starts at $2.75 for volumes above 100K.

About Atmel

Atmel is a worldwide leader in the design and manufacture of microcontrollers, advanced logic, mixed-signal, nonvolatile memory and radio frequency (RF) components. Leveraging one of the industry's broadest intellectual property (IP) portfolios, Atmel is able to provide the electronics industry with complete system solutions. Focused on consumer, industrial, security, communications, computing and automotive markets, Atmel ICs can be found Everywhere You Are(SM).

NOTE: Atmel(R), logo and combinations thereof, AVR(R), are registered trademarks, and Everywhere You Are(SM) and others are the trademarks of Atmel Corporation or its subsidiaries. Other terms and product names may be trademarks of others.

Information:

Information on Atmel's ATmega406 microcontroller can be retrieved at: http://www.atmel.com/dyn/products/product_card.asp?PN=ATmega406

  Press Contacts :

   Philippe Faure, Marketing Communication Manager - Microcontrollers
   Tel: +33 2 40 18 18 87, Email: philippe.faure@nto.atmel.com
   Veronique Sablereau, Corporate Communications Manager - Europe
   Tel: +33 1 30 60 70 68, Fax: +49 71 31 67 24 23
   Email: veronique.sablereau@atmel.com
   Clive Over, Director of Press Relations - USA and Asia
   Tel: +1 408 451 2855, Email: cliveover@atmel.com

CONTACT: Philippe Faure, Marketing Communication Manager -
Microcontrollers, +33 2 40 18 18 87, or philippe.faure@nto.atmel.com, or
Veronique Sablereau, Corporate Communications Manager - Europe,
+33 1 30 60 70 68, or fax, +49 71 31 67 24 23, or
veronique.sablereau@atmel.com, or Clive Over, Director of Press Relations -
USA and Asia, +1-408-451-2855, or cliveover@atmel.com

Web site: http://www.atmel.com/