SY20761BQDC - High Efficiency, 2A Two-cell Boost Li-Ion Battery Charger


  • Low Profile QFN3×3 Package
  • Integrated Synchronous Boost with 18V Rating Low RDSON FETs for High Charge Efficiency
  • Trickle Current / Constant Current / Constant Voltage Charge Mode
  • Programmable Input Voltage Threshold for Adaptive Current Limit.
  • Maximum 2A Constant Charge Current
  • Charge Current Information Indication.
  • Programmable Charge Timeout
  • Programmable Constant Charge Current
  • Selectable Constant Voltage
  • ±0.5% Battery Voltage Accuracy
  • Thermal Foldback Protection
  • External Shutdown Function
  • Input Voltage UVLO and OVP
  • Over Temperature Protection
  • Output Short Circuit Protection
  • Charge Status Indication
  • Normal Synchronous Boost Operation When Battery is Removed

Typical Application


The SY20761B is a synchronous Boost Li-ion battery charger for 2-cell with 3.6V-5.5V input, which integrates the power MOSFETs working with 1MHz switching frequency and the full protection functions. The charge current is up to 2A which can be programmed by using an external resistor for different portable applications. The IC can indicate the charge current information simultaneously. It also has a programmable charge timeout for safe battery charge operation and a programmable input voltage threshold for adaptive input current limit. The SY20761B can disconnect output when there is an output short circuit or shutdown. The IC consists of 18V rating FETs with extremely low ON resistance to achieve high charge efficiency and simple peripheral circuit design.

The SY20761B is available in QFN3×3 package to minimize the PCB layout size for wide portable application.


  • Cellular Telephones, PDA, MP3/MP4 Players
  • Digital Cameras
  • Bluetooth Applications
  • PSP Game Players, NDS Game Players