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Saturday, November 12, 2016

Active Filter Design with OpAmps

This is yet another Application Note of Exar found in- "Applications Data Book" June 1981. The Seven Scanned Pages as attachments can be viewed and studied at …

The availability of low cost dual or quad operational amplifier IC's have made the operational amplifier based active filter techniques cost effective over conventional passive filters. The recent availability of programmable quad operational amplifiers such as the XR-4202 or the XR-346 have provided the active filter designer with the flexibility to externally program gain-bandwidth product, supply current, input bias current, input offset current, input noise and the slew rate.

Application Note - AN-03 - Active Filter Design with IC Op-Amps

Active Filter Design with OpAmps

This application note is intended to familiarize the filter designer with the fundamentals of active filter design, using monolithic IC op amps. It presents a table of transfer functions and network equations for high-pass, low-pass, band-pass and band-reject filters. Several design examples are given to illustrate the respective merits and limitations of various filter configurations. Particular emphasis is given to applications of programmable quad operational amplifiers, such as the XR-4202, as an active filter element in FSK Modems.

Thursday, November 10, 2016

CircuitLab - Online Schematic Editor and Simulator

Draw and print beautiful schematics for lab reports. In-browser simulations make it easy to quickly learn electronics concepts. No need to Install, it is a Online Web Application !

CircuitLab - Online Schematic Editor & Simulator

Test and Simulate circuit ideas before breadboarding. SPICE-like models with a mixed-mode simulation engine help you apply one tool to a wide range of design tasks, from digital to analog, DC to VHF and beyond.

CircuitLab - Online Schematic Editor and Simulator

BJT Cascoded Active-load Differential Amplifier with CMFB

Build non-op-amp Common-Mode Feedback (CMFB) - This kind of high-gain differential input stage might be useful as part of an op-amp, but it's a bit silly to include an op-amp within a stage another op-amp......

Some Examples
  • 555 Timer as Oscillator / PWM Generator
  • 7805 & Wall-wart Experiencing Voltage Drop-out
  • Digital 4-bit counter and DAC
  • Diode full-wave (bridge) rectifier
  • Laplace transform step response and Bode plot
  • LED with resistor biasing
  • MOSFET switching inductive load
  • Op-Amp inverting / non-inverting amplifier
  • RLC resonance
  • Zener diode voltage reference

Friday, November 04, 2016

Electromagnetic Spectrum - Wavelengths

"Some insects, like bees, can see light of shorter wavelengths than humans can see."

This is something to Buzz about. This chart is excellent, a Pictogram. A small image with a Graphical, Complete and Concise expression of a Scientific Truth.

Electromagnetic Spectrum - Berkeley Lab

Radiation is energy that travels and spreads out as it goes-- visible light that comes from a lamp in your house and radio waves that come from a radio station are two types of electromagnetic radiation. Other examples of EM radiation are microwaves, infrared and ultraviolet light, X-rays and gamma-rays.....

Electromagnetic Spectrum

Measuring the electromagnetic spectrum

Faraday cages are structures - as small as a shoebox or as big as a building - that protect what's inside from surrounding electromagnetic radiation (EM).

National High Magnetic Field Laboratory - Faraday Cage

Here is a Electromagnetic Spectrum Chart from Sura.org - Southeastern Universities Research Association.

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