Features and Benefits
- Complete Pulse Charger for 1-Cell Lithium-Ion Batteries
- Sense Resistor Limits Maximum Current for Safety
- 1% Float Voltage Accuracy
- End-of-Charge (C/10) Detection Output
- Programmable Charge Termination Timer
- Internal 0.35Ω NMOS Switch
- No Blocking Diode Required
- SEL Pin to Set Either 4.1V or 4.2V/Cell (LTC1730-4)
- Low-Battery Drain (1µA Max) when Input Supply Is Removed
- Battery Temperature Sensing and Charge Qualification
- Automatic Trickle Charge for Low-Battery Cell
- Automatic Battery Refresh
The LTC1730 is a complete pulse charger for 1-cell lithium-ion batteries. When charging a depleted cell, the internal MOSFET is fully on allowing the current limited input power source to provide charge current to the battery, virtually eliminating heat generation in the charger.
As the battery accepts charge and approaches the programmed voltage, the internal MOSFET begins switching off and on with the duty cycle gradually decreasing as the battery approaches a fully charged condition. A programmable timer ends the charge cycle. The end-of-charge condition is indicated at the CHRG pin when the average charge current falls to C/10. Removing the input voltage puts the LTC1730 into a sleep mode, dropping the battery current drain to less than 1µA (maximum).
An external sense resistor limits the maximum charge current as a safety precaution against a user connecting a wall adapter with the incorrect or no current limit. The internal MOSFET prevents reverse battery current from flowing if the input voltage is shorted to ground, eliminating the need for a blocking diode.
The LTC1730-4 is available in the 16-pin SSOP package and the LTC1730-4.2 is available in the 8-pin SO package.
- Standalone Lithium-Ion Battery Charger
- Handheld Computers
- Cellular Telephones
Product Lifecycle Production
At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.
ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal.
Sample & Buy
The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.