DIY 5V 3A USB Charger for Car or Solar Panel (4-30V Input)

In this project, we will build a DIY 5V 3A USB Charger designed specifically for cars or solar panels using the NS6326B IC. This versatile charger is engineered to accept a wide input voltage range of 4-30V, making it highly adaptable to various power sources, from automotive batteries to solar-generated electricity. The NS6326B IC at its core ensures efficient voltage regulation and stable power delivery, ensuring your devices receive a consistent 5V output.

The charger boasts features like over-voltage protection, current sampling, and a robust power switch output mechanism, ensuring safety and reliability in diverse environments. Its 3A output capability ensures rapid charging for most USB-powered devices, from smartphones to tablets. Given its flexibility in input voltage and compact design, this charger is ideal for on-the-go applications, be it in cars, RVs, or remote locations powered by solar panels.

Supplies

NS6326 IC

100uF/35V electrolytic capacitor

470uF/16V electrolytic capacitor

0.1uF Capacitor 0805

47uH Inductor

USB Type A Port Female

LED 0805 (Red)

Resistor 0805 (220-ohm)

Step 1: NS6326B 4-30V Input 5V/3A Output Synchronous Buck Regulator

The NS6326B is a synchronous buck power management chip that supports high-voltage inputs. It can achieve a continuous current output of 3A within a wide input voltage range of 4~30V.

The NS6326B has excellent constant voltage/constant current (CC/CV) characteristics. It uses a current mode loop control principle to achieve a fast dynamic response. The NS6326B operating switching frequency is 130kHz, which has good EMI characteristics. Additionally, the chip includes multiple protection functions: over-temperature protection, output short circuit protection, and input under-voltage/over-voltage protection. The NS6326B uses a standard SOP8 package.

Step 2: Features of NS6326B

Wide input voltage range: 4V to 30V
Efficiency up to 92% and above
High constant current accuracy: ±5%
Constant voltage accuracy: ±5%
No external compensation required
Switching frequency: 130kHz
Input under-voltage/over-voltage, output short circuit, and overheat protection
SOP-8 package
Output current: 3A

Step 3: Pin Configuration

The SOP-8 pin diagram is shown, detailing the functions of each pin.

Step 4: NS6326B Typical Application Circuit

Step 5: Application Range

Car chargers/adapters
Linear regulator pre-regulators
Distributed power systems
Battery chargers

Step 6: 5V 3A USB Charger Circuit

Let us take a look at the 5V 3A USB Charger Circuit for a Car or Solar Panel. The schematic is modified from the NS6326B Typical Application Circuit.

In this schematic, the terminal J1 can be used for power input which can range from 4-30V. The input source could be a 12V Battery or a DC Adapter Supply. The input could also be a 24V Solar Panel.

The output can be taken from a pair of Male USB A ports. A terminal J2 is also provided so that a header or a jumper wire can be soldered to take power input.

Using the above schematic, you can design your own custom PCB. I used PCB for my project and soldered all the necessary components on it.

All the components on the front side and back side are soldered as per the circuit diagram.