Introduction: USB TO 12-V CONVERTER (Part-1)

Hello peeps! I am back again with an interesting instructable.

This project provides 12V output from any USB power source, like a PC USB port, USB adapter or power banks.LM2577ADJ boost converter IC is the heart of the project. The IC can handle load up to 800mA, it’s advisable to use the only 200mA load on the output to be on the safe side. The LM2577 are monolithic integrated circuits that provide all of the power and control functions for step-up (boost), fly back, and forward converter switching regulators.


  3. 200uF/ 16 V SMD 1210
  4. 470uF/16V
  5. 0.1uF SMD 0805
  6. 330nF SMD 08056
  7. MUR240 DIODE
  8. 100 uH 12MM*12MM SMD
  9. 2.2 K 0805 SMD
  10. 18 K SMD 0805
  11. 2 K SMD 0805
  12. LM2577 IC


The device is available in three different output voltage versions: 12V, 15V, and adjustable. Requiring a minimum number of external components, these regulators are cost-effective, and simple to use. Listed in this data sheet are a family of standard inductors and flyback transformers designed to work with these switching regulators. Included in the chip is a 3.0A NPN switch and its associated protection circuitry, consisting of current and thermal limiting, and under-voltage lockout. Other features include a 52 kHz fixed-frequency oscillator that requires no external components, a soft start mode to reduce in-rush current during start-up, and current mode control for improved rejection of input voltage and output load transients.

Default the output is set to 12V output, however, Output Voltage is adjustable using R2 and R3. Refer to datasheet of LM2577ADJ for more info. Output Voltage Formula VOut=1.23V (1+R2/R3) (Read Data Sheet for more information about Inductor value, Capacitor, Feedback resistors, Output current, and voltage)

Step 3: Manufacturing of PCB

I have designed my schematic using EAGLE CAD tool. The Gerber is attached here. I have uploaded the Gerber files onto LionCircuits.

They provide good quality PCBs at cheap prices and their Low-cost prototyping service is the best service for college and DIY projects.

2nd part of this instructable will be released soon.