SY20743QCC - 3A, Single Cell Li-Ion DC/DC Switching Charger with I2C Control, USB Detection and OTG JEITA Compliant, Power Path Management


  • High Efficiency 3A 1.5MHz Buck Mode Charger
–Support 3.9V-13.5V Input Voltage Range
–Programmable IDPM/VDPM to Support the USB and Adapter
–3.856V-4.624V Adjustable Charge Voltage
–Support Narrow VDC Power Path Management
–JEITA Compliance
– ±0.5% Charge Voltage Regulation
–Charge Status Outputs for LED or Host Processor
  • Maximum 1.2A 1.5MHz Boost OTG Current
–4.85V-5.3V Adjustable OTG Output Voltage
–Selectable OTG Output Current Limit
– ±1.5% Output Regulation in Boost Mode
–Soft-Start up to 500μF Capacitive Load
–Constant Current (CC) Limit
  • Full BATFET Control to Support Shipping Mode, Wake up, and  System Reset
  • Safety
–Battery Temperature Sensing for Charge and Boost Mode
–Battery Charging Safety Timer
–Thermal Regulation and Thermal Shutdown
–Input/System over-Voltage Protection
–MOSFET over-Current Protection
  • Low Battery Leakage Current and Support Shipping Mode
  • 4mm x 4mm QFN-24 Package

Typical Application


The SY20743 is a fully-integrated switching battery charger with system power path management devices for single cell Li-ion and Li-polymer battery in a wide range of tablet and other portable devices. Its low impedance power path optimizes switching conversion efficiency, reduces battery charging time and extends battery life during the discharging mode. The I2C serial interface with charging and system settings makes the device a truly flexible solution.
The device supports a wide range of input sources, including standard USB port and high power DC adapter. The SY20743 takes the result from detection circuit in the system, such as USB PHY device. The SY20743 meets USB On-the-Go operation power rating specification by supplying 5.15V (programmable) on BUS with current limit up to 1.2A (programmable).
The power path management regulates the system voltage slightly above battery voltage but does not drop below 3.5V minimum system voltage (programmable). With this feature, the switching converter will keep working to support the system load even when the battery is completely depleted or removed. When the input current limit or voltage limit is reached, the power path management will reduce the charging current to zero firstly. If the system load continues to increase, the power path will discharge the battery to provide the power required by system. This supplement mode operation prevents overloading the input source.
The device initiates and completes a charging cycle without software control. It automatically detects the battery voltage and charges the battery in five phases: battery short, preconditioning, constant current and constant voltage and top-off charging (optional). At the end of the charging cycle, the charger automatically will terminate when the charge current is below a preset limit in the constant voltage phase. When the full battery falls below the recharge threshold, the charger will automatically start another charging cycle. The SY20743 can be compliant with JEITA spec for the 4.2V Li-ion battery.
The device provides various safety features for battery charging and system operation, including negative thermistor monitoring, charging safety timer and over-voltage / over-current protections. The thermal regulation will reduce charge current when the junction temperature exceeds 110°C (programmable).
The STAT output reports the charging status and any fault conditions. The /PG output in the SY20743 indicates if a good power source is present. The INT immediately will notify the host when a fault occurs.
The SY20743 are available in QFN4x4-24 package.


  • Smart Phone
  • Tablet PC
  • Power Bank
  • Portable Internet Devices