• 1.1: OPERATIONAL AMPLIFIER
 Ideal Op-Amp
– Block diagram and Characteristics
– Op-amp parameters CMRR
– Slew rate
 – Concept of Virtual ground

• 1.2: APPLICATIONS OF OP-AMP
• Inverting amplifier
• –Summing amplifier
• – Non inverting amplifier
• – Voltage follower
• - Comparator
• – Zero crossing detector
• – Integrator
• – Differentiator-waveform generation (Schmitt Trigger
only)–RC Low pass Active filter.

• 1.3: OP-AMP SPECIFICATIONS OP-amp 741 –
Symbol – Pin diagram – Specifications

Schmitt Trigger- Square wave form
generator
• also called a regenerative comparator circuit
• positive feedback
• Purpose:
• to convert any regular or irregular shaped
input waveform into a square wave output
voltage

Schmitt Trigger

• Upper Threshold Voltage,
• 𝑽𝑼𝑻= 𝑽𝑺𝑨𝑻 *
𝑹𝒅𝒊𝒗 𝟏
(𝑹𝒅𝒊𝒗 𝟏+𝑹𝒅𝒊𝒗 𝟐)
• Lower Threshold Voltage,
• 𝑽𝑳𝑻= - 𝑽𝑺𝑨𝑻 *
𝑹𝒅𝒊𝒗 𝟏
(𝑹𝒅𝒊𝒗 𝟏+𝑹𝒅𝒊𝒗 𝟐)
• When Vin > VUT, output moves from + Vsat to - Vsat
• When Vin > VLT, output moves from - Vsat to + Vsat

Example:
• 𝑹𝒅𝒊𝒗 𝟏 = 𝑹𝒅𝒊𝒗 𝟐 = 10 k ohm
• 𝑽𝑺𝑨𝑻 = 5 V
• Find VUT and VLT

RC Low pass Active Filter

Applications Of Active Low Pass
Filters
• as hiss filters in audio speakers to reduce the high
frequency hiss produced in the system
• as inputs for sub woofers.
• These are also used in equalizers and audio
amplifiers.
• In analog to digital conversion these are used as
anti-aliasing filters to control signals.

PART-A Questions

Ideal Op-Amp

Slew rate

Concept of Virtual ground