USB Type-C Power Density Controller from Diodes Incorporated Built for Quick Chargers

February 03, 2020 by Gary Elinoff

The AP43771 features low standby power and an embedded MCU with one-time programmable memory.

Diodes Incorporated has unveiled the AP43771, a USB Type-C power delivery (PD) controller that is designed to work with other Diodes Incorporated products. Together, they can form the nucleus of offline chargers supporting Qualcomm’s Quick Charge (QC) 2.0, 3.0, and 4/4+ technology. Both 18 W and 33 W implementations are supported.



The AP43771. Image used courtesy of Diodes Incorporated


The AP43771 is Diodes Incorporated’s second-generation power delivery (PD) controller. The AP43771, used in combination with other Diodes Incorporated parts, is aimed at applications in rapid charging, AC/DC adaptors, and USB power delivery.

The unit features both one-time-programmable (OTP) ROM for main firmware and multi-time-programmable ROM for user configuration data.


Operating Characteristics

The AP43771 supports an operating voltage range of 3.3 V to 16 V. In its deep sleep mode, the device draws a maximum of 700 µA.

The new programmable power supply (PPS) feature, part of the latest iteration of the USB PD specification, is supportable by the AP43771.

The device adjusts the constant current in 50 mA and steps up to 6 A. Constant voltage can land anywhere between 3 V and 16 V in 20 mV steps.


Block diagram of the AP43771

Block diagram of the AP43771. Image used courtesy of Diodes Incorporated


The AP43771 supports constant voltage (CV) and constant current (CC) modes. 

In CV mode, output voltage will be fixed at the requested voltage so long as the output current is below the maximum allowed current.

In CC mode, the output voltage drops, and whenever the output current exceeds the allowed maximum, the source current is limited within 150 mA.


Built-in Protection

The AP43771 provides built-in defenses against overvoltage (OVP), overcurrent (OCP), short circuit (SCP), and overtemperature (OTP).

The OCP value is programmable.


18-watt and 33-watt Implementations

When designers are looking for an 18-W solution, they can use the APR43771 in combination with Diodes Incorporated’s APR34709 synchronous rectification (SR) switcher and the company’s AP39303 PWM switcher.


Typical USB PD 3.0 Solution

Typical USB PD 3.0 solution for AP43771, AP39303, and APR34709. Image (modified) used courtesy of Diodes Incorporated


If a 33-W charger solution is required, OEM’s can combine the AP43771 with Diode’s APR347 SR controller and the AP3303 PWM controller.


Typical USB PD 3.0 Solution

Typical USB PD 3.0 solution for AP3303, APR347, and AP43771. Image (modified) used courtesy of Diodes Incorporated


The APR347 and APR34709 are noted by Diodes Incorporated as integrating pulse linear regulators. They both support operating at a constant current mode, allowing output voltages as low as 2 V.

The AP3303 and the AP39303 are described by Diodes as quasi-resonant controllers and switchers, respectively. Both devices feature 120-V low dropout regulators (LDO) to regulate VCC.



The AP43771 is compliant with:

  • USB Type-C, specification Rev 1.2 
  • USB power delivery (PD), specification Rev 3.0 V 1.1
  • QC 4/4+ Compliance Certification by GRL (Report Number QC2019040851)


Physical Considerations

The AP43771 is lead-free and is fully RoHS Compliant. It is also a halogen- and antimony-free "green” device. For automotive applications, AEC-Q100, and PPAP compliance is available, as is manufacturing in an IATF 16949 certified facility.

The operating junction temperature range for the AP43771 is from -40℃ to +150℃ with a recommended operating range of -40℃ to +85℃.

The AP43771 is available in a 3 mm x 3 mm DFN30303-14 package.