Articles Signal Processing, Filters

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 ...

Simplicity and low cost sustain the popularity of passive PWM DAC ripple filters despite their limitations. One of these limitations is a high output impedance caused by the series sum of filter resistance(s) (R F in Figure 1, one resistor for each ...

Several years ago I wrote an article in Design Ideas called “Double µC’s PWM frequency resolution” ( Reference 1 ) where I mentioned how one can decrease the output ripple of a PWM-based DAC using two PWM signals having ...

When someone notices that two 8-bit DACs can be bought for less than one 16-bit DAC, a classic question is often asked: Why can’t you simply take two 8-bit DACs, assign one to the MSByte, the other to the LSByte, sum their outputs in a 28:1 ...

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 ...

You can effectively double the sample rate of a DAC by interleaving two DACs into a single unit. Updating each DAC on an alternating basis and switching to the appropriate output double the effective throughput of the overall system. It is ...

Readers will recognize the famous name Claude Elwood Shannon, widely renowned as the “father of information theory” and originator of many discoveries and inventions. Among these is an elegant and pioneering (First published in 1948!) ...

ADCs with differential inputs are becoming increasingly popular. This popularity isn't surprising, because differential inputs in the ADC offer several advantages: good common-mode noise rejection, a doubling of the available dynamic range ...