IC 4047 Calculator (Frequency and PWM)

We know that IC 4047 is very popular chip for making square wave oscillator, mainly used in inverters and other frequency generator circuits. But many people get confused when they have to calculate the correct resistor (R) and capacitor (C) values to get exact frequency like 50 Hz or 60 Hz.

So we thought, why not make simple tool where you can just enter R in ohms (Ω) and C in microfarads (µF) and it will instantly calculate the output frequency for you using the correct formula:
 F = 1 / (4.4 × R × C × 1e-6)

That is very helpful because now you do not need to do any manual calculation or use a calculator yourself, or try guessing R and C values.

Working Explanation

This calculator helps us calculate the output frequency in astable mode and pulse duration in monostable mode without doing any manual calculation.

Astable Mode Calculation

In astable mode, the IC keeps producing square wave pulses continuously without any external trigger. The important formula that controls the frequency is:
 F = 1 / (4.4 × R × C)

Where:

• F = Frequency in Hz
• R = Resistor value in ohms (Ω)
• C = Capacitor value in microfarads (µF)

Now we know that capacitance in microfarads is easy for us to handle, but in the formula, capacitor must be in farads. So, we multiply C by 1e-6 to convert microfarads into farads.

Then when we enter R and C values in the input fields, for example:
 R = 100000 (100 kΩ)
 C = 10 (10 µF)

The calculator calculates:
 period tA = 4.4 × R × C × 1e-6 (in seconds)
Then frequency F = 1 / tA

So now we get frequency in Hz directly without any headache.

This is very useful for making inverters or square wave oscillators where we want precise frequency like 50 Hz or 60 Hz.

Monostable Mode Calculation

Then, if we want monostable mode calculation, where IC gives just a single pulse every time triggered, the correct formula is:
 tM = 2.48 × R × C

Again, same logic applies.

• R in ohms (Ω)
• C in microfarads (µF)

We multiply C by 1e-6 to convert it to farads.

When user enters:
 R = 100000 (100 kΩ)
 C = 10 (10 µF)

Calculator calculates:
 tM = 2.48 × R × C × 1e-6 (in seconds)

So, we get pulse duration in seconds directly.
That means output pulse will stay HIGH for tM seconds before returning to LOW.

This is very useful for timer applications where we want a precise time delay.

Why This Is Useful

We know that doing logarithm or remembering the formulas every time is difficult. So this tool makes everything easy.

We just enter R and C values → click calculate → and get correct frequency or pulse duration.

Since this is based on official TI datasheet formulas, it is 100% accurate and reliable.

That is why this tool helps hobbyists, engineers, and students design their circuits easily without any manual calculation error.

Now you can easily design any IC 4047 based oscillator or timer with confidence, because this tool gives correct frequency or pulse duration every time without headache.

How It Works (Crude Style)

1. Astable Mode Calculator
    - We enter R in ohms (Ω), C in microfarads (µF).
    - Then it uses correct formula:
     F = 1 / (4.4 × R × C × 1e-6)
    - This gives accurate frequency in Hz.
2. Monostable Mode Calculator
    - We enter R in ohms (Ω), C in microfarads (µF).
    - Then it uses correct formula:
     tM = 2.48 × R × C × 1e-6 (seconds)
    - This gives pulse duration in seconds.

Example:

If you want 50 Hz in astable mode, then:
 R × C = 1 / (4.4 × 50) ≈ 0.004545
So R = 100kΩ and C = 47 nF, gives frequency close to 50 Hz.

If you want monostable pulse of 1 second, then:
 tM = 1 = 2.48 × R × C × 1e-6
 R × C = 1 / (2.48 × 1e-6) ≈ 403225
So R = 1 MΩ and C = 470 nF, gives ~1.16 seconds pulse.