An op-amp amplifier of gain 10 is used to amplify a sinusoidal signal with a peak amplitude of 0.5 V and frequency of 25kHz. What should be the minimum slew rate of the op-amp used ?

Concept:

When the input is a sinusoid given as:

Let, the gain of OPAMP is 'Av', the output is given as:

Vo(t) = Av Am sin(2πfmt)

The rate of change of output:

\(\frac{{d{V_o}}}{{dt}} = A_v A_m ~cos (2π f_m t)\)

The maximum rate of change = |Av A 2πfm cos(2πfmt)|max

\({\left. {\frac{{{d{V_o}}}}{{dt}}} \right|_{max}} = {A_v}A_m~2π {f_m} =Slew~Rate\)

Calculation:

Slew rate : 10 × 0.5 × 2π × 25 × 10³ = 785 × 10³ V/s 

= 0.785 V/μs