The Tuofeng Era 100W 1A1C dual port car charger has USB-A and USB-C interfaces, with the USB-C interface supporting 65W fast charging and the USB-A interface supporting 35W fast charging. The total output power is 100W, and the USB-C port is equipped with a built-in voltage regulator circuit that supports 20V output and 12V battery for cars. This car charger can also be used to charge laptops, making it more practical.

• Input: DC12-24V

• USB-C output: 5V3A, 9V3A, 12V3A, 15V3A, 20V3.25A

• USB-A output: 5V3A, 9V2A, 12V2.92A

• Total output: 100W

CX8838B Applied to Tuofeng Era 100W 1A1C Car Charging Solution

The Tuofeng Era 100W 1A1C dual port car charger uses a CX8838B synchronous four switch voltage regulator internally, supporting a Z-high 32V wide input voltage to meet the wide voltage application of car charging. The continuous load current can reach 20A, and the output voltage can be stably adjusted when the input voltage is higher or lower than the output voltage to support various voltage regulation applications, providing a Z-optimal solution for high-power Type-C PD car chargers.

The CX8838B controller adopts constant time control in step-down, step-down, and step-up operation modes to achieve excellent load and voltage adjustment. The programmable switching frequency can be set to 150kHz, 300kHz, 600kHz, or 1.2MHz.

The chip also has programmable soft start function and provides various protection functions, including cycle by cycle current limiting, input undervoltage lockout (UVLO), output overvoltage protection (OVP), input overvoltage protection, over temperature protection, and output short circuit protection. At the same time, the CX8838B controller comes with frequency jitter function to improve EMI performance and easily pass EMC radiation certification, perfectly solving the problem of engineers rectifying EMC.

Under simulated 24V DC input, the USB-C port supports FCP, SCP, AFC, QC3.0, PD3.0, PPS, QC4+, and Samsung 5V2A charging protocols.

In addition, the PDO message shows that the USB-C port has five fixed voltage ranges of 5V3A, 9V3A, 12V3A, 15V3A, and 20V3.25A, as well as one PPS voltage range of 3.3-11V5A.

It was measured that the USB-A port supports FCP, SCP, AFC, QC3.0, and Samsung 5V2A charging protocols. In addition, the output performance of the two interfaces is also exactly the same when measuring 14V DC input.

The two voltage rise and fall switch tubes use a CX4040, which is a 40V withstand NMOS with a conductivity of 5.5m Ω and is packaged in a DFN3.3 * 3.3 package.

Both MOS transistors on the output side are a 40V withstand NMOS with a conductivity of 4.3m Ω and are packaged in PPAK5 * 6.

The built-in protocol chip of the charger is a highly integrated Type-C/Type-A fast charging protocol chip, which supports mainstream fast charging protocols such as PD, QC, FCP, high and low voltage SCP, AFC, SFCP, and PE, and supports two working modes: optocoupler feedback and FB feedback. The protocol chip integrates CV/CC control loop, Type-C interface logic, fast charging protocol controller, and various security protection functions. By combining ACDC or DCDC with a small amount of peripheral components, a complete high-performance Type-C/Type-A fast charging solution can be formed.

The output VBUS switch tube is a 30V withstand PMOS with a conductivity of 8.5m Ω.

At the back of the USB-A interface board, a synchronous step-down chip is welded, with current detection resistors and fuses. The components are very streamlined.

The USB-A port's step-down chip adopts a synchronous step-down converter with built-in protocol function. The chip integrates a 3.5A high-efficiency synchronous rectification step-down converter internally, supporting charging protocols such as PPS, PD, QC, AFC, FCP, SCP, PE, SFCP, and low-voltage direct charging. It supports CC/CV mode, and requires only a small amount of external devices to form a complete high-performance multi fast charging protocol charging solution.

The Tuofeng era car supports a total output power of 100W when charging, with the USB-C port supporting 65W charging, the USB-A port supporting 35W charging, the USB-C port using voltage conversion, supporting 20V output, and supporting 3.3-11V 5A PPS fast charging output. It also supports laptop charging, and has good compatibility with Android phone fast charging, meeting daily usage needs.

This car has two independent circuits inside the charging system. The USB-C interface uses a voltage drop circuit, the USB-A interface uses a voltage drop circuit, the USB-C interface uses a protocol chip paired with a CX8838B voltage drop controller, and the USB-A interface uses a synchronous voltage drop chip with comprehensive protocol support.