Part $3-$ DTMF Keypad Design

You will build a DTMF based keypad $($see Figure $4)$ utilizing the signal generators in the lab. Note that you must make appointments to be able to use them.

Investigate what is a DTMF$.$ You will generate the corresponding sounds when you push any of the buttons of the keypad. Do not forget to use a speaker or a buzzer. You do not have to build the entire keypad. You need to build a circuit for one button only. Though, the row frequency and the column frequency will be adjusted through the signal generator during the demonstration. So$,$ with a single button and the corresponding circuitry, you will be able to mimic sounds for each button during the demonstration.

$-$ Propose the schematic of the corresponding button and the circuit.

$-$ Do a comprehensive theoretical analysis of the circuit.

$-$ Implement it in LTSpice.

$-$ Implement it in a physical circuit.

$-$ Do necessary measurements or analysis to completely validate the circuit and the desired behavior.

Figure $4.$ A representative keypad utilizing DTMF$.$

i need the shematic part and implement it to LTspice