1. SNS COLLEGE OF TECHNOLOGY COIMBATORE -35
WAVEFORM GENERATION USING OP AMP
R.PRABHA
AP/ECE

2. Op-amp square wave generator

3. SQUARE WAVE GENERATOR:-
Square wave output are generated when the op-amp is forced to operate in saturated region that is. The op-amp is forced to swing between +Vsat and –Vsat there by resulting in square wave output.
Initially capacitor is equal to zero at the instant when dc supply voltage is +Vcc.+
This means that the voltage at the inverting terminal is zero. Voltage V1 at the non inverting terminal is due to offset output voltage (VOOT) and values of R1,R2 resistors.
Thus Vid = V1 (due to inverting terminal)
The output (Vo) is feedback to the circuit and will charge to the capacitor connected at the inverting terminal as soon as V2 is greater than V1 the output of the op-amp is switched to negative saturation

4. TRIANGULAR WAVE GENERATOR

5. TRIANGULAR WAVE GENERATOR:-
Triangular wave generator can be form by connecting an integrator to the square wave generator.
This circuit requires dual op-amp,two capacitor and five resistors. For fix R1,R2,C be frequency of triangular wave depends on R
As value of R is increase or decrease the frequency of triangular wave is increase or decrease.
All though the amplitude of square wave form is constant the amplitude of triangular wave will increase or decrease with its frequency.
The output of A1 is square wave which is given as an input to A2 as A2 act as an integrator. Its output is triangular wave form.

6. RAMP GENERATOR CIRCUIT USING OP-AMP

7. RAMP GENERATOR CIRCUIT USING OP-AMP:-
The ramp generator obtain from the figure.
The only modification is inclusion of a potentiometer R7 in the non inverting(+) terminal of the integrator op-amp.
Due to the additional potentiometer R7,it is possible to adjust the voltage at non inverting terminal of the integrator op-amp anywhere between +Vcc snd –Vee .
Due to this, an additional dc level will be added to the integrator output.
This added dc level in the integrator output will alter the duty cycle of the comparator output. Either ON time is longer than OFF time or vice versa.

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