LTC1730 - Lithium-Ion Battery Pulse Chargers with Overcurrent Protection

Features

  • 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 0.35 Ohm 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

Typical Application

LTC1730 Typical Application

Description

The LTC®1730 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.

Packaging

CAD Symbols and Footprints: The downloadable Zip file below contains the schematic symbol and PCB footprints.

For complete and up to date package information and drawings, please refer to our packaging page

Part Number Package Code Temp Package
Drawing
RoHS
LTC1730EGN-4#PBF SSOP-16 GN E 05-08-1641 (GN16) Yes
LTC1730EGN-4#TRPBF SSOP-16 GN E 05-08-1641 (GN16) Yes
LTC1730ES8-4.2#PBF SO-8 S8 E 05-08-1610 (S8) Yes
LTC1730ES8-4.2#TRPBF SO-8 S8 E 05-08-1610 (S8) Yes


LTC1730 Package Drawing
LTC1730 Package Drawing

Order Info

  • Part numbers ending in PBF are lead free. Solder plated terminal finish (SnPb) versions are non-standard and special terms and conditions and pricing applies if available. Please contact LTC marketing for information.
  • Part numbers containing TR or TRM are shipped in tape and reel or 500 unit mini tape and reel, respectively
  • Please refer to our general ordering information or the product datasheet for more details

Package Variations and Pricing

Part Number Package Temp Price
(1-99)
Price
(1k)*
RoHS
LTC1730EGN-4#PBF SSOP-16 E $2.33 $2.05 Yes
LTC1730EGN-4#TRPBF SSOP-16 E $2.11 Yes
LTC1730ES8-4.2#PBF SO-8 E $2.07 $1.85 Yes
LTC1730ES8-4.2#TRPBF SO-8 E $1.91 Yes
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* 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 Linear Technology sales office or authorized distributor.

Demo Boards

Linear Technology offers many demo boards free of charge to qualified customers. Contact your local sales office or distributor to inquire about a demo board. Certain demo boards are also available for sale via credit card on this website. Demo boards are for evaluation purposes only. It remains the customer’s responsibility to verify proper and reliable operation in the actual end application.

Part Number Description Price Documentation
DC384A LTC1730EGN-4 | Li-Ion Battery Pulse Charger, Single Cell, 4.1V/4.2V, Requires 1A Current Limited Input Power Source, Vin=5V to 10V Contact Factory
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Click here to view our complete list of demo boards

Applications

  • Standalone Lithium-Ion Battery Charger
  • Handheld Computers
  • Cellular Telephones

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Design Tools

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