Li-Ion Battery Charger requires no external components.
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Press Release Summary:
Model LTC4058 charges single-cell 4.2 V Li-Ion batteries from 4.25-6.5V input sources in constant-current and constant-voltage modes. It operates autonomously, independent of firmware for battery monitoring, charge termination, and protection. Thermal regulator guarantees maximum charge current regardless of ambient temperature. By combining voltage reference with remote battery sensing, unit provides ±1% accurate battery float voltage.
Original Press Release:
800mA Single-Cell, Li-Ion Battery Charger Allows Maximum Charge Rates with 9mm² Footprint
MILPITAS, CA - August 27, 2003 - Linear Technology Corporation introduces the LTC4058, a linear 1-cell Li-Ion battery charger that requires no external power components and operates autonomously, independent of firmware for battery monitoring, charge termination and protection. A patented thermal regulator guarantees maximum charge current regardless of ambient temperature without additional heat sinking. This feature eliminates the need for worst-case heat management precautions and requires smaller PCB area than conventional linear chargers. Moreover, the LTC4058 includes three pins for reporting the value of charge current used for gas gauging, the presence of input power supply, and charge status. Applications include digital still cameras, portable POS and diagnostic equipment as well as cell phones, PDAs and USB equipped handheld devices.
The LTC4058 charges single-cell 4.2V Li-Ion batteries from 4.25V to 6.5V (10V max.) input sources in two operating modes, constant-current and constant-voltage. The charger terminates the charging process during constant-voltage mode when the charge current decreases to one-tenth the value of the fast charge current. By eliminating the need for a sense resistor, the designer can adjust the fast charge current with an inexpensive programming resistor and still obtain ±5% charge accuracy. By combining a precision voltage reference with remote battery sensing, the LTC4058 provides a ±1% accurate battery float voltage. The LTC4058 includes protection features such as overvoltage, soft-start, overheating and reverse current protection, as well as battery care features such as pre-conditioning and automatic recharge.
The LTC4058 is rated for -40°C to 85°C operation. Pricing for 1,000-piece quantities begin at $1.70 each.
Summary of Features: LTC4058
o Programmable Charge Current up to 800mA
o Complete Linear Charger in DFN Package
o No MOSFET, Sense Resistor or Blocking Diode Required
o Thermal Regulation Maximizes Charge Rate without Risk of Overheating
o Battery Kelvin Sensing Improves Float Charging
o Charges directly from USB
Company Background
Linear Technology Corporation was founded in 1981 as a manufacturer of high performance linear integrated circuits. Linear Technology products include operational, instrumentation and audio amplifiers; voltage regulators, power management devices, DC-DC converters and voltage references; comparators; monolithic filters; communications interface circuits; one-chip data acquisition sub-systems; pulse-width modulators and sample-and-hold devices; and high frequency devices. Applications for Linear Technology's high performance circuits include wireless and broadband telecommunications infrastructure, cellular telephones, networking products and satellite systems, notebook and desk top computers, computer peripherals, video/multimedia, industrial and medical instrumentation, automotive electronics, factory automation, process control, military and space systems, and high-end consumer products including digital cameras, MP3 players and other electronic products.
