Circuits & Schematics

Dual precision comparators are needed in many designs, such as for industrial and instrumentation applications, to generate accurate pulse-width modulated (PWM) waveforms with very high ( 99%) and very low ( 1%) duty-cycle percentages. This design ...

This modular resistor load bank uses a unique topology to reduce the number of switches and resistors while providing the maximum number of steps. An array or bank of load resistors is often required for testing power products, characterization of ...

Introduction In general, muting and/or signal switching is done by relays, FETs or CMOS analogue switch ICs. All have limitations, but a little known technique that really doesn't look like it could ever work is to use bipolar transistors. The ...

Famous analog designer and author Jim Williams published an awesome design in 1986 for a 100-MHz voltage to frequency converter ( Ref. 1 ). He named this high-climber (picture it on the roof of the Empire State building swatting biplanes out of the ...

Frequent design idea (DI) contributor Nick Cornford recently published a synergistic pair of DIs “A pitch-linear VCO, part 1: Getting it going” ( Ref. 1 ) and “A pitch-linear VCO, part 2: taking it further” ( Ref. 2 ). The ...

In Part 1, we saw how to make an oscillator whose pitch, as opposed to frequency, can be made proportional to a control voltage. In this second part, we’ll look at some alternative ways of arranging things for other possible applications. To ...

If you've ever designed an RF oscillator, you've probably encountered squegging. Sometimes called motor boating, squegging causes oscillators to start and stop at frequencies much lower than the frequency of interest. Viewed on an ...

The recent Design Idea “Getting an audio signal with a THD 0.0002% made easy” [ 1 ] discloses a low THD sine generator which led me to dust off a design that I had published in AudioXpress magazine [ 2 ] (see Figure 1). Figure 1. A ...

It’s remarkable how many switching regulator chips use the same basic two-resistor network for output voltage programming. Figure 1 illustrates this feature in a typical (buck type) regulator. See R 1 and R 2 where: Quantitatively, the V ...

Traditionally, the reception quality of a digital receiver is expressed in terms of BER (bit-error rate). This figure is the proportion of received bit errors in a given period. Typically, you measure the BER in the lab by applying an RF signal, ...