Features and Benefits
- 22V Maximum Voltage for Wall Adapter and USB Inputs
- Charge Single-Cell Li-Ion Batteries from Wall Adapter and USB Inputs
- Automatic Input Power Detection and Selection
- Charge Current Programmable Up to 950mA from Wall Adapter Inputs
- Overvoltage Lockout for Wall Adapter and USB Inputs
- Battery Detection Input Disables Charger When No Battery is Present
- No External MOSFET, Sense Resistor or Blocking Diode Needed
- Thermal Regulation Maximizes Charge Rate Without Risk of Overheating*
- Preset Charge Voltage with ±0.6% Accuracy
- Programmable Charge Current Termination
- 40µA USB Suspend Current in Shutdown
- Charge Status Output
- Automatic Recharge
- Available Without Trickle Charge (LTC4078X)
- Available in a Thermally Enhanced, Low Profile (0.75mm) 10-Lead (3mm × 3mm) DFN Package
The LTC4078/LTC4078X are standalone linear chargers that are capable of charging a single-cell Li-Ion/Polymer battery from both wall adapter and USB inputs. The chargers can detect power at the inputs and automatically select the appropriate power source for charging.
No external sense resistor or blocking diode is required for charging due to the internal MOSFET architecture. The LTC4078/LTC4078X feature a maximum 22V rating for both wall adapter and USB inputs, although charging stops if the selected power source exceeds the overvoltage limit. Internal thermal feedback regulates the battery charge current to maintain a constant die temperature during high power operation or high ambient temperature conditions. The float voltage is fixed at 4.2V and the charge current is programmed with an external resistor. The LTC4078/LTC4078X terminate the charge cycle when the charge current drops below the programmed termination threshold after the final float voltage is reached.
Other features include battery present detection, automatic recharge, undervoltage lockout, charge status outputs, and “power present” status outputs to indicate the presence of wall adapter or USB power. The device is offered in a low profile (0.75mm) 3mm × 3mm 10-lead DFN package.
- Cellular Telephones
- Handheld Computers
- Portable MP3 Players
- Digital Cameras
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.
LTC4078 Companion Parts
Recommended Related Parts
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.