I made the following photo-transistor circuit to sense light with the exact parts shown. Resistors are 5% tolerance 1/4 watt. The circuit does work, but what I would like to know is how do I calculate the bandwidth of the circuit as it is now? By bandwidth, I mean the baud rate (bits per second).
From what I understand from the internet, transistors exhibit miller effect capacitance and logic gates experience propagation delays so is it as simple as multiplying the total miller capacitance by the total resistance of all resistors then adding the nand gate propagation delay? or am I missing something?
VCC here is +5VDC fed from a regulated power supply.
And if my theory is correct, then could I convert the 2.2K base resistor to 100 ohms safely and gain better speed without anything overheating? The reason why I want the resistor in the first place is because in the actual project, the photo-transistor will be manually plugged in after the rest of the circuit is complete and if some goof connects a pin to VCC and its not the ground pin, then the base resistor will be connected to VCC which to me is better than a direct connection from base to VCC.
Sorry, but the people I work with are newbies.