Product category:
Power Supply ICs and Controllers
News Release from: Summit Microelectronics | Subject: SMB139
Edited by the Electronicstalk Editorial
Team on 18 June 2007
Li-cell charger reduces power real
estate
Single-cell Li-ion and Li-polymer linear battery charger chip is ideal for portable applications that require the smallest possible charging footprint.
Summit Microelectronics has further expanded its family of programmable battery charger ICs with the introduction of the SMB139 single-cell, Li-ion and Li-polymer linear battery charger The device's battery charging profile can be configured to adapt easily to new system designs and battery types
This article was originally published on Electronicstalk on 23 Apr 2001 at 8.00am (UK)
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Furthermore, the SMB139's tiny size makes it ideal for portable applications that require the smallest possible charging footprint.
The SMB139 integrates many protection features, thereby ensuring the highest level of safety and eliminating the need for additional external components.
The SMB139's tiny 1.3 x 2.1mm chip-scale package delivers a charging solution that occupies significantly smaller board space than traditional implementations.
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The flexible programmability with the I2C interface allows convenient parametric and functional control and provides unlimited design flexibility, both in-system and during the development stage.
Unlike other linear chargers offered in packages with a limited number of pins, the SMB139's chip-scale package allows the integration of a higher number of features, including critical charging protection functionality.
Overall, the SMB139 enables new standards for performance, mobility and safety in portable consumer electronics.
"Reducing footprint requirements while maintaining high performance and design flexibility allows the SMB139 to set new standards for charging small- and medium- capacity Li-ion and Li-polymer batteries", says George Paparrizos, Summit Marketing Director.
"The SMB139 offers the highest number of advanced safety functions, further reducing the number of components and the board space required to safely charge the new generation of portable electronic devices".
The SMB139 comprises a highly integrated, 210mA linear charging solution that uses a fully programmable algorithm for single-cell Li-ion and Li-polymer cells.
All charging parameters - precharge/fast-charge/charge termination current, cell float/precharge voltage, battery temperature/timer safety limits - are configurable via the I2C/SMBus interface, enabling a wide variety of algorithms without hardware changes.
Real-time adjustment of the charging profile also minimises charging time and maximises safety.
The SMB139 can be programmed either dynamically (real-time using volatile registers), by a microcontroller and software via the I2C/SMBus port, or statically (preprogrammed using nonvolatile registers).
If the static programming mode is used there is no need for software to access the I2C/SMBus interface and the SMB139 functions independently as a customised, but parametrically fixed solution.
Static configurability allows the same product to be used in different system designs and/or with different battery types and technologies, resulting in significantly lower qualification/inventory costs and sourcing risks.
The SMB139 operates from a +4.35 to +6.5V input making it ideally suited for either USB or AC adapter power sources.
However, for applications where the AC adapter may be poorly regulated and/or an aftermarket or counterfeit product is used, the SMB139 will tolerate +10V inputs without damage.
Ensuring long battery life when not connected to a DC power source, the reverse leakage current is less than 2uA.
In addition, when the I2C/SMBus port is not utilised for charge control/monitoring, the SMB139 provides a control pin for real-time, two-level charge current configuration, as well as a status output to drive an LED for indicating charge status and fault conditions.
Enhancing system reliability, the SMB139 integrates input/output over-voltage, short-circuit and thermal protection circuits.
A variety of fault and status registers are also available for real-time monitoring charging and system operation.
The SMB139 also protects the battery pack with a programmable battery temperature monitor and charge safety timers to prevent dangerous charging conditions.
Furthermore, to protect deeply discharged cells, the SMB139 has a 3mA "trickle charge" mode below 2.0V.
This mode allows safe, controlled recovery of the deeply discharged cell until it can accept normal charging currents.
All these protection features allow designs to meet strict industry safety standards without the need for additional external components and cost.
The SMB139 is well suited for a wide range of space-constrained handheld consumer devices such as Bluetooth headsets, stereo headsets, flash-based portable music players, noise-cancellation headphones, robotic toys and wristwatches/PDAs.
In particular, it is the ideal battery charging solution for applications that use small-capacity Li+ batteries and/or use a single USB connector to provide both data and power.
The SMB139 has an operating temperature range of -30 to +85C and is available in the 1.3 x 2.1mm 15-ball chip-scale package that is lead-free and RoHS-standards compliant.
Available now in production quantities, the device is priced at US $0.85 each in quantities of 10,000 units.
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