DIY Fast Charging with IP6518: 45W USB PD Solution

If you're interested in integrated Type-C PD protocol desktop fast charging PCBs, take a look at this article.

After testing, with a 30V input and 15V2A output, the efficiency is approximately 93%, supporting many fast charging protocols, including DCP, QC2.0, QC3.0, PE+1.1, PE2.0, FCP, AFC, SFCP, SCP, and USB PD.

The IP6518 is a buck converter with integrated synchronous switches, supporting 13 different output fast charging protocols. It also supports Type-C output and USB PD protocol, providing a complete solution for car chargers, fast charging adapters, and smart power strips. The IP6518 has an internal power MOS, an input voltage range of 10.5V to 32V, and an output voltage range of 3V to 20V. It can deliver up to 45W of output power and automatically adjusts the output voltage and current based on the detected fast charging protocol. Typical output voltages and currents include: 3V3.6A, 5V3.4A, 7V3A, 9V3A, 12V3A, 15V2.3A, and 20V2.3A. The buck converter efficiency of the IP6518 can be as high as 97%.

First, let's look at the finished product. For input, you can use a 35V 220uF Chemi-Con black diamond capacitor. If the input exceeds 30V, you need to switch to a capacitor rated for 50V. For auxiliary filtering, two Samsung 50V 10uF ceramic capacitors are used, and for the output, two Panasonic SEK series solid-state capacitors (25V 270uF) are used. On the bottom, there's a Samsung 50V 10uF ceramic capacitor. The output ripple should be minimal.

The image shows the board charging a Xiaomi 20Ah power bank with a 30V input. Theoretically, the maximum input for the power bank is 15V3A or 20V2.25A, but it only negotiated the 15V2A 30W setting. The reason is unclear.

Since the A-port and C-port are connected in parallel, special care must be taken to ensure only one device is connected to either port at a time.

On the back side, the C-port is soldered to the back of the A-port using a 16-pin terminal. The C-port supports PD and other fast charging protocols, but the A-port does not support PD protocol.

Schematic Diagram

The official simplified application schematic for the IP6518 is shown below, and you only need a few simple peripheral components to complete it.

Pin Description

The IP6518 comes in two models, so be sure to distinguish between them when using:

5IC Selection Guide:

· The IP6518 enables PD 15V and 20V output functions, ideal for smart power strip applications. When using the PD 20V function, the input must be 28V, and the output capacitor must be increased to 1000uF or more.

· The IP6518C enables the PD 12V function, ideal for car charger applications.

Finished.