PLEASE REVIEW MY FIRST PCB. EEG, analog/digital.

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tdengineer
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Joined: 21 Oct 2025, 13:27

PLEASE REVIEW MY FIRST PCB. EEG, analog/digital.

#1 Post by tdengineer » 21 Oct 2025, 13:31

Left side = electrode input, that goes into an electro discharge protection ic then into the resistor arrays then into the capacitor arrays then into the ads 1299.



Right side = Female input pins that connect to the spi lines of the ads1299 and dvdd power. I will plug in an esp32 dev board with short jumper wires. the esp will be powered off of the same power as the ads1299 pcb power. (3.3v regulator).



Top side (power) = I will plug in an external battery that will go into 3.3v regulator then into the charge pump. The dvdd power will come off of a parallel branch of the 3.3v regulator output. The ads1299 analog power 2.5 and -2.5v will come from the charge pump.



I got it as good as I can, I am kind of confused about the return paths.



PCB BOARD SPECS = 4 layers. SIGNALS/GND/POWER/SIGNALS. POWER PLANES ARE ON POWER LAYER. RED TRACES ARE TOP LAYER. BLUE LAYER IS BOTTOM LAYER





ADS1299 = ADC CONVERTER

LDL1117S33R = 3.3V REGULATOR

LM27762DSSR = CHARGE PUMP WITH 2.5V AND -2.5 REGULATED OUTPUT

ESD PROTECTION IC'S = TPD4E1B06DCKR

RESISTOR ARRAYS = CAY16-2201F4LF

CAPACITOR ARRAYS = CKCL44X7R1H102M085AA

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