amplifiers which do operations

1. Resources reminder

The Google Drive docs folder has a dedicated folder opamps for information. This includes AN-7 and:

2. Integrator

an 20 opamp integrator
Figure 1. Integrator structure

3. Logarithmic amplifier → multiplier

















4. Interesting multiplier

an 20 opamp multiplier

5. Op amp problems

5.1. Generic +gain

  • Draw circuit for a non-inverting amplifier with a gain of (close to) +4 V/V.

  • Use only E12-series resistor values.

5.2. Input resistance spec

  • Amplifier with a low-frequency gain of −12 V/V.

  • Input resistance between 10 kΩ and 50 kΩ.

5.3. Find bandwidth

What is the -3 dB frequency of a circuit using an NE5532A op amp configured for a low-frequency gain of 15 V/V.

5.4. Max bandwidth with DC coupling

(this is a hard problem!)

Requirements:

  • DC gain of 100 V/V ±1%

  • Output offset voltage Vos(out) ≤ |0.1 mV| (typical)

  • Maximize the -3 dB frequency bandwidth with response down to DC.

Some videos discussing this problem related to the μCurrent product:

6. Another set of op amp notes

day35 Google Doc

  • This has a large example about simulating op amp things using CircuitLab.

  • There is a companion video linked in the doc.

7. Mackie Onyx 80 Series analog audio mixer

Onyx 24

Schematics from Mackie