I know that bits per second and hertz are two different units. This question will help me in designing an oscilloscope with proper ADC sampling frequency for viewing communication protocols.
Just imagine a communication protocol(eg: I2C) which has a data rate of 1Mbps. As per the protocol, there are different fields where we can keep data, address etc. But I am currently assuming that each bits in this protocol is toggling one after the other. Then this looks like a square wave.
In a square wave, the fist half will high(Logic 1) and the second half will be low(Logic 0) or vice versa. So in one cycle we have two bits. As per this visualisation 1Hz i.e 1 cycle/sec is equivalent to 2bits/sec(or 2bps).
Similarly for 1Mbps data rate, there will be 1000000 bits per second. If we assume each bit is inverse of the other(i.e they toggle like a square wave) and as per our calculation, 2bits will be present in one cycle of square wave, then 1000000 bits per second = 500000Hz (1000000bps /2 bits in one cycle). So 1Mbps is equivalent to 500kHz square wave.
Is my visualisation correct(I converted bits per second to hertz)?
I want to make a USB oscilloscope in which I want to select a proper sampling frequency for the ADC. So in this case if I assume 1Mbps as 500kHz, then for a good signal display(signal reconstruction based on the ADC samples), sampling should be done at 10 times the signal frequency i.e 5Mega samples per second (500kHz *10 = 5MHz)
Is this calculation correct ?
Also does this mean that I can view this communication protocol's voltage levels clearly on a oscilloscope having bandwidth of 5MHz (500kHz *10)?