I need to use an ADC to convert analog signals from pressure and temperature sensors to a microcontroller (Teensy 4.0). I'm confused if I should use an ADC with Parallel or SPI interface. I'm currently designing the data processing unit for a rocket and I am worried that if I need 8 inputs from an ADC, It'll take 8 clock cycles to read from 8 registers, but if I read from an ADC with a parallel interface then I can read all the values at the same time. I am confused about how to go about this.
ADC I am thinking of using with SPI interface: http://www.ti.com/lit/ds/symlink/ads8168.pdf?HQS=TI-null-null-mousermode-df-pf-null-wwe&DCM=yes&ref_url=https%3A%2F%2Fwww.mouser.com%2F
This is the ADC with a parallel interface: https://www.mouser.com/datasheet/2/256/MAX11047-MAX11059-1514141.pdf
Edit: More on the application, I need to read the inputs from pressure transducers and temperature sensors in the rocket fuel pipeline. Using the information from the sensors I need to send an output from the MCU to MOSFET relays which will then open the solenoid valves on the pipeline.
Best Answer
In your application it doesn't matter much, whether it's serial or parallel. Your bottleneck is going to be solenoid/physical movement of the fuel anyway (order of magnitude ms for solenoids, even less for fuel itself). That would put your attitude determination frequency in range of couple kHz max. 8 clock cycles at 600MHz is much less than that, I would worry about your control software implementation more. Just go with whatever is easier to implement, I suggest using SPI over DMA - just set it up to read all your ADC channel values sequentially, process them once all have arrived.