LTC1734 - Lithium-Ion Linear Battery Charger in ThinSOT

The LTC1734 is a low cost, single cell, constant-current/constant-voltage Li-Ion battery charger controller. When combined with a few external components, the SOT-23 package forms a very small, low cost charger for single cell lithium-ion batteries.

The LTC1734 is available in 4.1V and 4.2V versions with 1% accuracy. Constant current is programmed using a single external resistor between the PROG pin and ground. Manual shutdown is accomplished by floating the program resistor while removing input power automatically puts the LT1734 into sleep mode. Both the shutdown and sleep modes drain near zero current from battery.

Charge current can be monitored via the voltage on the PROG pin allowing a microcontroller or ADC to read the current and determine when to terminate the charge cycle. The output driver is both current limited and thermally protected to prevent the LTC1734 from operating outside of safe limits. No external blocking diode is required.

The LTC1734 can also function as a general purpose current source or as a current source for charging nickel-cadmium (NiCd) and nickel-metal-hydride (NiMH) batteries using external termination.

Features
  • Low Profile (1mm) ThinSOT
  • No Blocking Diode Required
  • No Sense Resistor Required
  • 1% Accurate Preset Voltages: 4.1V or 4.2V
  • Charge Current Monitor Output for Charge Termination
  • Programmable Charge Current: 200mA to 700mA
  • Automatic Sleep Mode with Input Supply Removal
  • Manual Shutdown
  • Negligible Battery Drain Current in Shutdown
  • Undervoltage Lockout
  • Self Protection for Overcurrent/Overtemperature
Typical Application

Applications
  • Cellular Telephones
  • Handheld Computers
  • Digital Cameras
  • Charging Docks and Cradles
  • Low Cost and Small Size Chargers
  • Programmable Current Source
Packaging
Order Information
Part NumberPackageTempPrice(1-99)Price (1k)*
LTC1734ES6-4.1#PBFSOT-23E$1.70
LTC1734ES6-4.1#TRMPBFSOT-23E$1.70$1.33
LTC1734ES6-4.1#TRPBFSOT-23E$1.70$1.31
LTC1734ES6-4.2#PBFSOT-23E$1.70
LTC1734ES6-4.2#TRMPBFSOT-23E$1.70$1.33
LTC1734ES6-4.2#TRPBFSOT-23E$1.70$1.31
Demo Boards
Part NumberDescriptionPrice
DC370A-ALTC1734ES6-4.1 | Li-Ion Battery Charger$75.00
DC370A-BLTC1734ES6-4.2 | Li-Ion Battery Charger$75.00
Datasheet
Reliability Data
Related Product
LTC1734 - Lithium-Ion Linear Battery Charger in ThinSOT
LTC1734 - Lithium-Ion Linear Battery Charger in ThinSOT
R402 Reliability Data
LTC1734 Footprints and Symbols