Standalone 1.2A Li-Ion Battery Chargers Automatically Select Between USB and Wall Adapter Inputs
Linear Technology Corporation introduces the LTC4096/X standalone dual-input linear battery chargers. These devices charge single-cell Li-Ion/Polymer batteries from wall adapter or USB power sources. The LTC4096/X use a constant-current/constant-voltage algorithm for charging, with programmable charge current up to 1.2A from a wall adapter supply or up to 1A from a USB supply while automatically sensing the presence of voltage at each input. Applications include PDAs, MP3 players, digital cameras, lightweight portable medical and test equipment and large color screen cell phones.
The LTC4096/X feature a final float voltage accuracy of ±0.6% and are equipped with a patented thermal regulation scheme that maximizes the charging rate without the risk of overheating. The devices are extremely flexible with the following features programmable via a single resistor: wall adapter charge current, USB charge current and charge termination current. As standalone chargers, they do not require an external microcontroller to terminate charge, simplifying design. Other features include trickle charge for battery pre-conditioning ("X" versions disable trickle charge), undervoltage lockout, automatic recharge, charge status indicators and an input power present output (PWR) pin with 120mA drive capability. To preserve battery energy, the LTC4096/X draws <50uA from the battery terminal in standby and <20uA in shutdown mode.
The LTC4096/X are offered in a low profile (0.75mm) 10-lead 3mm × 3mm DFN package. The total solution footprint is very compact since no external MOSFET, sense resistors or blocking diodes are required. They are rated for operation from –40°C to 85°C. 1,000-piece pricing begins at $1.50 each.
Summary of Features: LTC4096/X
- Charges Single Cell Li-Ion/Polymer Batteries from Wall Adapter & USB Inputs
- Standalone Operation: No External Controller Required to Terminate Charge
- Automatic Input Power Detection
- Programmable Charge Current up to 1.2A from Wall Adapter Input via Resistor
- Programmable USB Charge Current up to 1A via Resistor
- Thermal Regulation Maximizes Charge Rate without Risk of Overheating
- No MOSFET, Sense Resistor or Blocking Diode Required
- "X" Version Disables Trickle Charge
- Low-Profile (0.75mm) 3mm × 3mm DFN-10 Package
Dual Input Standalone Li Battery Chargers
Editor's Contact Information
- Doug Dickinson