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The AP43331N is a highly integrated secondary side constant voltage (CV) and constant current (CC) controller, which is compatible with Qualcomm Quick Charge 3.0 (QC 3.0) High Voltage Dedicated Charging Port (HVDCP) Class A specification.

The AP43331N allows for selection of the output voltage of an AC−DC USB charger based on commands from the Portable Device (PD) being powered. Selecting a higher charging voltage will reduce the charging current for a given power level resulting in reduced IR drops and increased system efficiency. The USB−bus voltage can be controlled in discreet steps (QC 3.0’s step is 0.2V). The output current is limited not to exceed maximum allowable power level.

The AP43331N resides at the secondary side of the charger. It includes voltage and current feedback regulation eliminating the need for a shunt regulator such as TL431.

The AP43331N has a current sense amplifier to amplify the detected output current signal for contribution to accomplishing CC feature and output cable voltage compensation function.

The AP43331N incorporates a decoder used to translate Qualcomm QC3.0 protocol into internal configuration indicator, according to which the CV/CC loops will regulate the output voltage and current.

The AP43331N integrates a safe−discharge circuitry to quickly and reliably discharge output capacitors when the output voltage is switched down.

The AP43331N automatically keeps 5V output voltage in case that the connected portable device is not compatible with the QC3.0.

The AP43331N is available in SO-8 package.


  • AC/DC Adapters
  • Battery Chargers
  • LED Drivers


  • Constant Voltage and Constant Current Regulation
  • Supporting Qualcomm QC 3.0 Class A (3.6V Up to 12V)
  • Output Cable Voltage Compensation
  • High Precision CV/CC References
  • Fast Dynamic Response
  • Removing the Need for a Shunt Regulator Such As TL431
  • Output Capacitor Safe−Discharge Circuitry At the Output Voltage Switched Down.
  • Output Over Voltage Protection (OVP)
  • Output Under Voltage Protection (UVP)
  • Operating Supply Voltage: 3.2V to 12V

Product Specifications

Product Parameters

VCC Max 20 V
Operating Current 770 µA
Protocol Compatible QC3.0
Voltage Sense Reference 0.5V/0.9V/1.2V
Current Sense Reference 75mV/50mV/37.5mV
UVLO 2.8 V

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Orderable Part Number Authorized Distributor Quantity Inventory Date Buy Online Region
AP43331NMTR-G1 Digi-Key Electronics 3960 8/21/2019 Buy Now United States
AP43331NMTR-G1 Mouser Electronics Inc. 3970 8/21/2019 Buy Now United States