Power supplies play a very important role in testing electronic circuits. Power supplies are used to get a constant voltage or constant current out of them. Most modern power supplies come with a lot of features, such as temperature monitoring, constant current and constant voltage mode. We can set a desirable range of potential and current by adjusting the potentiometer knob. But these power supplies cost a lot and are very bulky in nature. On the other hand in basic to advanced electronics most of the circuit works at voltage less than 20V. That’s why I am in search of a power supply module, which can deliver power in this range. And to get rid of this bulky power supply, I found the best method to be USB power delivery.

With USB-C chargers, now we can get different voltages which helps to fast charge the batteries. Lithium polymer batteries inside the mobile phone can now be charged with higher current to implement fast charging. All this happens with a buck converter circuit at the battery interface. But it is not easy to get a desirable output from a USB-C fast charger.

All this depends upon the interfacing circuit we are using. The best method to use a dedicated power delivery IC, I found the CH224k is a single-chip solution that integrates USB PD and various fast-charging protocols, supporting PD3.0/2.0, BC1.2, and other boost fast-charging standards. It features automatic VCONN detection, analog E-Mark chip compatibility, and supports power delivery up to 100W.

Power Supply Making approach from Fast Charger:

With this CH224k multiple voltages like 5,9,12,15,20V are possible with different settings of input jumpers. It can provide a max of 20V at 5A of constant current, hence a max power of 100W can be delivered. But we need a variable power supply, to implement this LM2576 buck converter is the best option to go with. First the power delivery voltage is selected then this voltage given to the buck converter circuit, a potentiometer is used to tune the voltage according to the one's need. Moreover here we have onboard voltage and current monitoring options.

With a built-in PD communication module, high integration level, and simplified peripherals, it ensures efficient functionality. The chip includes integrated output voltage detection and offers protections such as over-temperature and over-voltage safeguards. I have integrated all that things on a PCB from PCBWAY, PCBWAY can be a one stop solution to all your circuit DIY needs from PCB to stencil, from Assembly to 3D printing. With over 10 years of experience and remarkable work in this field PCBWAY becomes the number one choice among hobbyists. Sign-up now from here and get free coupons for your first PCB order.

Features:

• Supports input voltage range from 4V to 22V.
• Compatible with PD3.0/2.0, BC1.2, and various fast-charging protocols.
• Offers USB Type-C PD support with positive and negative plug detection and automatic switching.
• Includes E-Mark simulation, automatic VCONN detection, and supports up to 100W PD power requests.
• Allows dynamic adjustment of requested voltage through multiple methods.
• Features high integration in a single chip, simplified peripherals, and cost-effective design.
• Equipped with built-in overvoltage protection (OVA) and over-temperature protection (OTA) modules.

Components Required:

• WCH224K IC
• 10K multi turn potentiometer
• LM2596 Buck boost conversion Kit
• 10K, 1K resistor 0603
• SMD LED 0603
• LM358 op amp
• Shunt 0.1OHM
• DIP switches
• Push ON/OFF switch
• USB type C jack
• 5V Zener diode
• 3 wire voltmeter
• 1uf, 100nf, 10nf, 10uf capacitors 0603
• PCB from PCBWAY

Circuit Diagram:

I divided the schematics into 3 main sections and subsections to each unit according to the input output. The first section carries power delivery output, second has buck conversion, 3rd has power monitoring.

First section:

The main input type C, which takes input from the fast charging unit. CH224K is supplied from here, having some decoupling...