Golden Arduino

Goal

The main purpose of this lab is to design an Arduino board which shows significant reduction in switching noise and cross talks compared to commercial Arduino in the market. The Board is designed with all the best practices in reducing noise and Near Field Emissions.

Plan of Record

Features of the Board

1. At the input switch is added to get the input power either from the power jack or from the USB but not from both simultaneously.

2. 500mΩ sense resistor is used in the power path to measure inrush current in the circuit.

3. Low Drop Out (LDO) is used to generate 3.3V stable voltage supply from 5V supply.

4. TVS Diode is added for protection against ESD to the USB slot of the computer.

5. ICSP Pins are included for initial Boot loading of ATmega 328P.

6. A 16 MHz clock is used at ATmega 328.

7. CH340G is used for USB UART Communication.

8. A 12 MHz clock is used at CH340G.

9. Headers like Commercial Arduino along with extra GND headers pins for all the pins.

10. Ferrite filter on AVCC pin of ADC because of its sensitivity to noise.

11. All IC inputs have decoupling/bypass capacitor.

12. The Bottom layer of the PCB is poured with copper and used as a ground plane.

Schematic

Layout

Assembled PCB

Near Field Emission Comparison

I have measured all possible waveforms on commercial Arduino and did a comparison of all waveforms with Golden Arduino to prove there is 20 to 50% noise reduction in Golden Arduino. Below is a detailed report for your reference.