Multifunction IC has battery charger and buck converter.

Press Release Summary:




Supplied in 3mm x 3mm DFN package, LTC4080 integrates USB-compatible battery charger that can charge single-cell Li-Ion battery up to 500 mA without overheating device or surrounding components. IC also incorporates 300 mA standalone linear buck converter that features selectable mode operation and synchronous rectification to achieve efficiencies up to 96%. It operates from 2.7-5.5 V input and has corresponding output range of 0.8 V to VBAT.



Original Press Release:



500mA Standalone Li-Ion Battery Charger plus Synchronous Buck Converter in 3mm x 3mm DFN



MILPITAS, CA - June 15, 2006 - Linear Technology Corporation introduces the LTC4080, a multi-function IC featuring a standalone linear battery charger and a highly-efficient synchronous buck converter. The USB-compatible battery charger can charge a single-cell Li-Ion battery up to 500mA without overheating the device or surrounding components. The 300mA buck converter features selectable mode operation and synchronous rectification to achieve efficiencies up to 96%. The device is designed to work with supplies up to 5.5V, including those within USB specifications and from 5V wall adapters. Its 3mm x 3mm DFN package ensures a tiny solution footprint for space-constrained, smaller battery capacity powered handheld applications such as wireless headsets, Bluetooth devices, portable MP3 players, and multi-function wristwatches.

The LTC4080's battery charger requires no external MOSFET, sense resistor or blocking diode. A patented thermal regulation scheme prevents the junction temperature of the IC from exceeding 115°C by reducing charge current during high power or high ambient temperature operation. This fully-featured charger offers timer termination, recharge, and C/10 detection. Other features of the LTC4080 include a charge status indicator, a 4.2V 0.5% accurate float voltage, 5% charge accuracy, and an open drain AC Present status pin to indicate the presence of an input supply such as a wall adapter. Charge current is adjustable with a standard off-the-shelf resistor. During shutdown, the supply current is only 5uA and battery drain current is less than 1uA.

The highly-efficient synchronous step-down converter features a 2.7V to 5.5V input operating voltage range (powered from the BAT pin) with corresponding output voltage range from 0.8V to VBAT. Burst Mode® operation reduces supply current to only 23uA to maximize light load efficiency, but can be disabled via an external pin in favor of fixed constant frequency (2.25MHz) operation if very low switching noise is required.

The LTC4080 is housed in a tiny 10-lead 3mm x 3mm DFN package and is rated for operation from -40°C to 85°C. Pricing starts at $1.90 each in 1,000-piece quantities.

Summary of Features: LTC4080
Standalone Linear Charger with Integrated Buck Converter in 3mm x 3mm DFN Package
Programmable Charge Current up to 500mA with ± 5% Accuracy
Safety Timer Termination with C/10 Charge Current Detection Output
Thermal Regulation Maximizes Charge Rate without Risk of Overheating
Charge Status and AC Present Indicators
No External MOSFET, Sense Resistor or Blocking Diode Required

High Efficiency Synchronous Buck Converter: up to 96%

Buck Converter Output Current: 300mA
Buck Converter Input Voltage Range: 2.7V to 5.5V (powered from BAT pin)

Buck Converter Output Voltage Range: 0.8V to VBAT
Buck Mode Selection: Low Quiescent Current Burst Mode or Constant Frequency

Tiny Low-Profile (0.75mm) 10-Lead 3mm x 3mm DFN Package
Standalone Li-Ion Charger with Synchronous Buck Converter

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, 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. For more information, visit www.linear.com.

LT, LTC, LTM and Burst Mode are registered trademarks of Linear Technology Corp.

Contacts

North America and General Information
John Hamburger
Tel: (408) 432-1900 ext. 2419
jhamburger@linear.com

Doug Dickinson
Tel: (408) 432 1900 ext. 2233
ddickinson@linear.com

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