The LTC3550EDHC-1 is a standalone linear charger with a 600mA monolithic synchronous buck converter. It is capable of charging a single-cell Li-Ion battery from both wall adapter and USB inputs. The charger automatically selects the appropriate power source for charging.
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 currents are programmed with external resistors. The LTC3550EDHC-1 terminates the charge cycle when the charge current drops below the programmed termination threshold after the final float voltage is reached. With power applied to both inputs, the LTC3550EDHC-1 can be put into shutdown mode reducing the DCIN supply current to 20μA, the USBIN supply current to 10μA, and the battery drain current to less than 2μA.
The DC/DC converter switching frequency is internally set at 1.5MHz, allowing the use of small surface mount inductors and capacitors.
VoutLTC3550AdjustableLTC3550-1 1.875VFeature
- Charges Single-Cell Li-Ion Battery from Wall Adapter and USB Inputs
- Automatic Input Power Detection and Selection
- Charge Current Programmable Up to 950mA from Wall Adapter Input
- Adjustable Output, High Efficiency 600mA Synchronous DC/DC Converter
- 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
- 1.5MHz Constant Frequency Operation (Step-Down Converter)
- 18μA USB Suspend Current in Shutdown
- “Power Present” Status Output
- Charge Status Output
- Automatic Recharge
- Available in a Thermally Enhanced, Low Profile (0.75mm) 16-Lead (5mm × 3mm) DFN Package
Applications
- Cellular Telephones
(Picture: Pinout)
