Articles - Analogue Design - 3

There are two basic filter topologies that everyone recommends when they start to design their signal chain: multiple-feedback (MFB) or Sallen-Key topologies. But what are the differences and why would you choose one over the other? MFB filtering ...

Sometimes, the need arises for a low-distortion buffer amplifier capable of handling bipolar signals. You can use an op amp or integrated buffer for these applications, but for more flexibility, a discrete design may prove useful. Applications ...

A Zobel network is useful in making a reactive load appear as a pure resistance to a driving source prone to stability problems ( Reference 1 ). A typical situation is an audio power amplifier driving a loudspeaker, modeled at first approximation ...

A bi-directional current source for a grounded load will always have some complication in its construction. The improved Howland Current Pump as shown in Figure 1 is the most frequent choice for this function. The Howland requires carefully matched ...

The analog priority amplifier shown in Figure 1 was originally conceived as part of a multiple output power supply where the voltage regulation was based on the level of the highest channel. Another application was an engine control system with an ...

Most designers consider slowness in diodes to be an imperfection or a limitation. Why not take a more positive view of the situation? After all, a zener or an avalanche diode is no more than a diode with a limited breakdown voltage, and you can ...

The editors of EDN will tell you that the Design Ideas section is the most popular section of the website, this goes back to the print editions, where that was the first section that most if not all readers turned to first upon getting a new issue. ...

The design of a standard inverting integrator is simple when bipolar supplies are available, but it's cumbersome with a unipolar supply. To allow adequate headroom for the output, the circuit must be biased away from ground, often at half the ...

Known devices for taking the square root contain an operational amplifier and a multiplier connected in a feedback loop. The accuracy of these devices depends on the method of building the multiplier, with the most accurate using logarithm and ...

Every PWM DAC design needs analog filtering to separate the desired PWM duty-cycle-proportional DC component from unwanted AC ripple. The simplest of these is the basic RC low-pass filter, which gives a peak-to-peak ripple amplitude (for the worst ...