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## 555 Astable Multivibrator calculator for frequency, duty cycle

This page covers 555 astable multivibrator calculator for frequency and duty cycle calculations. The formula or equations used for this 555 Astable Multivibrator calculator using two methods are also mentioned.

### 555 Astable Multivibrator Calculator #1

This calculator takes R1 resistor, R2 resistor and Capacitor C as inputs and provides frequency and duty cycle as outputs.

Resistance (R1) in K-Ohm (Input-1)   :

Resistance (R2) in K-Ohm (Input-2)   :

Capacitance (C) in µF (Input-3)   :

Frequency of AMV (output-1) :

Duty Cycle of AMV(output-2) :

Time High of AMV(output-3) :

Time Low of AMV(output-4) :

EXAMPLE 555 Astable multivibrator to calculate frequency/duty cycle:
INPUTS: R1 = 10 KOhm, R2 = 10 KOhm, C1 = 0.220 µF (i.e. 220 nF)
OUTPUT: Frequency = 218.1818 Hz, Duty cycle (%) = 0.66, tHIGH = 0.003049 Sec, tLOW = 0.001524

### 555 Astable Multivibrator calculator formula/equation The figure-1 depicts pin diagram of 555 IC used as astable multivibrator.

Following formula or equation is used for astable Multivibrator frequency and duty cycle calculator#1 as mentioned above. ### 555 Astable Multivibrator Calculator #2

This calculator takes Frequency, Duty Cycle and C as inputs and provides R1 and R2 as outputs.

Frequency in Hz, (Input-1)   :

Duty Cycle in % (Input-2)   :

Capacitance in µF (Input-3)    :

Resistance R1 in K-Ohm (output-1) :

Resistance R2 in K-Ohm (output-2) :

EXAMPLE 555 Astable multivibrator to calculate R1/R2:
INPUTS: Frequency = 218 Hz , Duty Cycle = 0.60 second , C = 0.220 µF
OUTPUT: R1 = 6 KOhm , R2 = 12 KOhm

Following formula or equation is used for astable Multivibrator frequency and duty cycle calculator. ### Astable Multivibrator Calculator #3

Inputs: Number of NOT gates, propagation delay of each Gate
Outputs: Time period, Frequency

Number of NOT gates (Input-1) :

Propagation delay in nsec (Input-2) :

Time period of square wave in sec (output-1) :

Frequency of square wave in Hz (output-2) :

EXAMPLE:
Inputs: number of gates = 3 , Propagation delay of each gate = 1 ns
Outputs: Time period of square wave = 6 nsec (6.0 x 10-9), Frequency of square wave = 166,666666Hz (166.666666 MHz)

### Astable multivibrator Calculator using NOT Gates or Inverter Gates The figure depicts bistable and astable multivibrator (AMV) made using NOT gates (i.e. inverter gates).

Following formula or equation is used to calculate frequency and time period of multivibrator made using NOT gates or inverter gates.

Time period of AMV, T = 2 *n * tpd
Where,
n = Number of inverter gates or NOT gates
tpd = Propagation delay time of each inverter
T = Time period of square wave generated by AMV or ring oscillator.

Frequency of AMV (f) = 1/T = 1/2 *n * tpd

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