here's the start of my pcb layout for a fuel injector driver project i am working on. this is about actual size. i have to fit about 70 components onto the board, and it is a challenge. so what is it? its a board that drives auxilliary fuel injects using a PWM signal from another source. i designed in injector monitoring by way of op-amp, some 4bit clocks, and quad OR gates. op-amp output should go high when known current passes through a precision current sense resistor. this output is fed to the master reset of each clock. the clocks advance with every PWM pulse, so hence if two PWM pulses are seen but no master reset (no current through resistor) then the clock's 2nd bit goes high which triggers OR gate to drive a LED. driver stage is using 3 IRF1404 nFET's so it can handle lots of current (which is also a challenge on pcb). so far i have down the op-amps and current sense resistor, and unwired clocks and OR gates. any questions please post, comments welcomed.

 

just showing the progress (pic below). i am using my licensed version of DipTrace to build 2 layer pcb. i'm kinda going about it the wrong way. DipTrace allows me to 1st build a schematic and then import that schematic into pcb layout and it auto routes and auto places components onto the board. however, DipTrace is not smart enough to know everything, such as having huge trace areas to carry current, etc.