So I’m designing a pcb with mostly smd components and I need help verifying it. This will be my first
ever pcb altough i do already have some experience with breadboards. The goal of this pcb is to power [ 2 servos, 1 rgb led, 1 teensy 4.0, 4 pyro channels, 1 imu, 1 barometer,1 buzzer and a DC motor], in order to control a rocket model thrust vectoring and reaction wheel. I'd be glad if you could point out errors in my design, best practices when designing the pcb board or anything sub-optimal. Thanks a lot
The L28x driver is really just about the worst driver to use for your project. It will dissipate 2V to over 4V of your motor supply as wasted heat. Pololu, among others, have much more efficient MOSFET output drivers, Choose a driver that will handle the motor stall current (see motor data sheet) and rated motor supply voltage.
Avoid linear voltage regulators. They are less efficient than swiching regulators (boost, buck).
What are the MOSFETS for the igniters? Are they logic level inputs?
As I previously said this is one of my first projects and i planned on using DMN305 mosfets since i've seen them used in similar projects to mine, but I lack the knowledge to choose it myself. All i know is that it should be fast, esd protected, well documented and low resistance.
A main thing to look for is the voltage at which Rds(on) is specified. That is the voltage on the gate that will turn the MOSFET on and the current (Ids) that pass at that gate voltage. In this case, Rds(on is speced at 4.5V which means that it is logic level (Rds(on) <= 5V or so). If it were only speced at 10V, it would not be logic level.
