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

Overview:
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.
Bill of Materials
The following are the components required to make a 5A 3A USB Charger Circuit.
S.N.
Components
Quantity
Purchase Link

NS6326 IC

AliExpress

100uF/35V electrolytic capacitor

AliExpress

470uF/16V electrolytic capacitor

AliExpress

0.1uF Capacitor 0805

AliExpress

47uH Inductor

AliExpress

USB Type A Port Female

AliExpress

LED 0805 (Red)

AliExpress

Resistor 0805 (220-ohm)

AliExpress
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
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
Pin Configuration
The SOP-8 pin diagram is shown, detailing the functions of each pin.
Pin Number
Pin Name
Description
Function

NC
Floating Pin
–

CSN
Output Voltage
Output voltage pin

CSP
Current Sampling Pin
This pin is used to detect and set the output constant current value; the size of the output constant current value is set by R3: ICC-Mode = Vcs/R3
​

VIN
Power Supply
Power supply pin, this pin should be connected to at least a 100uF/35V electrolytic capacitor to the ground to avoid large voltage fluctuations at the input during operation
5,6
SW
Power Switch Output
This pin is the switch node, connected to the inductor, used for power output to the load
7,8
GND
Ground
Ground pin
NS6326B Typical Application Circuit
Application Range
Car chargers/adapters
Linear regulator pre-regulators
Distributed power systems
Battery chargers
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.
Testing & Operations
After assembling the hardware, you can start testing the PCB Board. You may connect a 12V Lead-Acid Battery at Input terminal.
The on-board LED on the board will turn on indicating the board is powered on. You may use a multimeter to check the input and the output voltage.
Similarly, instead of 12V DC Battery, you may connect a 24V Solar Panel.
You can charge your mobile phone using the USB Port.
The 5V 3A USB Charger can be useful is so many other applications that requires constant power source.