Electronics News
Archive : 9 October 2008 год
The device is designed to maintain regulation while delivering 330-mA typical peak current for systems with a high surge current upon turn-on. During start-up, an active pull-down circuit improves the output transient response and regulation. In shutdown mode, the output automatically discharges by connecting the output to ground through a 100-Ohm-n-channel MOSFET. For safe operation, the device offers thermal overload (+160°C typical) and built-in short circuit protection (500mA typical), with a 1-μA maximum shutdown current at +85°C. The SiP21110 operates over a junction temperature range of -40°C to +125°C.
The EFE-300 delivers 300W continuous power (400W peak for 10 seconds) with nominal outputs of 12V / 25A or 24V / 12.5A, and the EFE-400 delivers 400W continuous power (530W peak for 10 seconds) with nominal outputs of 12V / 33.3A or 24V / 16.7A. All models can be precisely factory programmed to accommodate non-standard system voltages. An additional 12V / 0.25A fan supply is also available and all models operate from 90 - 264VAC input with dual fusing as standard. Active power factor correction ensures EN61000-3-2 compliance. Other EMC improving design features, such as the use of SiC diodes, ensure curve B EMC performance with a significant margin.
All products in TDK-Lambda’s EFE Series are approved to IEC/EN/UL/CSA 60950-1 for general purpose applications and IEC/EN 61010-1 for laboratory and process control applications. In addition, the units carry the CE mark according to the LV Directive and come with a three-year warranty.
Texas Instruments introduced three smart battery management integrated circuits that improve measurement and protection of multi-cell, lithium-based battery packs. The controllers simplify design in multi-cell lithium-based rechargeable batteries used in uninterruptible power supplies and applications, such as cordless power tools, power-assisted bicycles, and portable medical and test equipment. TI’s bq78PL114 battery management controller provides complete lithium battery system control, monitoring and safety functions for 4-series cells.
The device integrates accurate battery fuel gauge technology with extremely efficient cell balancing, short-circuit detection and battery protection. The bq78PL114 is completely user-configurable with parametric tables set in Flash memory to support a variety of Li-Ion and Li-Polymer chemistries, operating conditions, safety control and data reporting design requirements. The device can be configured easily using TI’s bqWizard fully programmable graphical user interface and requires no algorithm or firmware development.
Dual-cell monitor provides scalability up to 12-cells In addition to the controller, TI introduced its bq76PL102 dual-cell battery monitor, which performs simultaneous voltage and temperature monitoring of each cell and reports those parameters over TI’s proprietary PowerLAN communications interface. By leveraging the PowerLAN interface, a designer can combine multiple bq76PL102 monitor devices with the bq78PL114 controller to create a smart battery solution for up to 12 rechargeable cells. Real-time communications is possible in all operating conditions, even during widely fluctuating load conditions. The scalable PowerLAN architecture also provides robust communications in tough electromagnetic and radio frequency interference situations, while avoiding excess power draw and a large number of discrete components.
PowerPump precise cell balancing technology
Partitioning of the battery monitoring function cell-by-cell enables a more accurate state of charge measurement. With this in mind, the bq78PL114-based system helps extend battery life and system runtime with TI’s patented PowerPump cell balancing technology. This technology uses a charge-transfer methodology that does not waste excess energy as heat, but moves energy dynamically from cell to cell with very high efficiency. Precise balancing occurs at every stage of operation – at charge, discharge and rest. With PowerPump technology, cell balancing is automatically coordinated between all cells in the system.
Additional battery protection for 5- to 10-cell systems
TI adds another degree of integration, safety and protection to multi-cell applications with a new lithium-based battery protector and analog front end for 5- to 10-cell battery systems. The bq77PL900, which includes an I2C interface for communication with a host controller, can also operate as a stand-alone battery protection circuit. The device integrates a 5-V and a 3.3-V LDO to help power the host controller or other circuits in the system. For more information on the bq77PL900. The low-power battery protection circuit includes a voltage translation system to measure temperature, system current and individual cell voltages. Cell balancing can be performed through bypassing current around selected cells. The bq77PL900 also provides full safety protection for overvoltage, undervoltage, overtemperature and overcurrent in discharge and short circuit during discharge conditions.
Pricing and Availability
The bq78PL114 battery management controller and the bqPL900 lithium-based battery protector are available in volume today from TI and its authorized distributors. The bq78PL114 comes in a 48-pin, 7 mm x 7 mm QFN package, with a suggested resale price of $5.65 in 100-piece quantities. The bq77PL900 comes in a 48-pin SSOP package, and has a suggested resale price of $3.70 in 100-piece quantities. The bq76PL102 is currently sampling with expected availability later in the fourth quarter. It comes in a 16-pin, 3 mm x 3 mm QFN package, with a suggested resale price of $1.90 in 100-unit quantities. Evaluation modules of all three devices and design application notes are available.