Power Management Battery Management Battery Charger IC Linear Battery Chargers

LTC1732-4 & 4.2 - Lithium-Ion Linear Battery Charger Controller

Features

  • Complete Linear Charger Controller for 1-Cell Lithium-Ion Batteries
  • Preset Charge Voltage with 1% Accuracy
  • 4.5V to 12V Input Voltage Range
  • Programmable Charge Current
  • C/10 Charge Current Detection Output
  • Programmable Charge Termination Timer
  • Small, Thin 10-Pin MSOP Package
  • Select Pin to Charge Either 4.1V or 4.2V Cells (LTC1732-4)
  • Automatic Sleep Mode When Input Supply is Removed (Only 7µA Battery Drain)
  • Automatic Trickle Charge of Low Voltage Cells
  • Programmable for Constant-Current-Only Mode
  • Battery Insertion Detect
  • Input Supply (Wall Adapter) Detection Output
  • 4.05V Recharge Threshold for 4.2V Cells (LTC1732-4.2)
  • 3.8V Recharge Threshold for 4.1V or 4.2V Cells (LTC1732-4)

Typical Application

LTC1732-4 Typical Application

Description

The LTC1732 is a complete constant-current/constant-voltage linear charge controller for lithium-ion (Li-Ion) batteries. Nickel-cadmium (NiCd) and nickel metal-hydride (NiMH) batteries can also be charged with constant current using external termination. Charge current can be programmed with 7% (max) accuracy using external sense and program resistors. An internal resistor divider and precision reference set the final float voltage with 1% accuracy. The SEL pin allows users to charge either 4.1V or 4.2V cells.

When the input supply is removed, the LTC1732 automatically enters a low current sleep mode, dropping the battery drain current to 7µA. An internal comparator detects the end-of-charge (C/10) condition while a programmable timer, using an external capacitor, sets the total charge time. Fully discharged cells are automatically trickle charged at 10% of the programmed current until cell voltage exceeds 2.457V.

The LTC1732 begins a new charge cycle when a discharged battery is connected to the charger or when the input power is applied. In addition, if the battery remains connected to the charger and the cell voltage drops below 3.8V for the LTC1732-4 or below 4.05V for the LTC1732-4.2, a new charge cycle will begin.

The LTC1732 is available in the 10-pin MSOP package.

 Float VoltageRecharge Voltage
LTC1732-4 4.1V or 4.2V (pin select) 3.8V
LTC1732-4.2 4.2V 4.05V
LTC1732-8.4 8.4V 8.05V

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
LTC1732EMS-4.2#PBF MS-10 MS E 05-08-1661 Yes
LTC1732EMS-4.2#TRPBF MS-10 MS E 05-08-1661 Yes
LTC1732EMS-4#PBF MS-10 MS E 05-08-1661 Yes
LTC1732EMS-4#TRPBF MS-10 MS E 05-08-1661 Yes


LTC1732-4 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
LTC1732EMS-4.2#PBF MS-10 E $2.52 $2.15 Yes
LTC1732EMS-4.2#TRPBF MS-10 E $2.21 Yes
LTC1732EMS-4#PBF MS-10 E $2.52 $2.15 Yes
LTC1732EMS-4#TRPBF MS-10 E $2.21 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.

Click here to view our complete list of demo boards

Applications

  • Cellular Phones
  • Handheld Computers
  • Charging Docks and Cradles

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