Circuits & Schematics Oscillators

A random-bit-sequence generator is basic equipment for prototyping and testing any data-transmission system. You use such a generator when measuring BER (bit-error rate) and pattern-dependent effects in a transmission system. Such effects can ...

A broadband source of white noise can be useful for measuring and testing communications equipment. The source in Figure 1 is simple and produces a large noise signal at its output terminals. The circuit comprises a zener diode and a few amplifying ...

The circuit here is an oscillator with an unusual frequency divider that I designed when I was developing an RF system. I needed a stable and accurate 455 kHz digital signal generator that used as few components as possible. The signal generator ...

Digital potentiometers are versatile devices; you can use them in many filtering and waveform-generation applications. This Design Idea describes an oscillator in which setting the resistance of two digital potentiometers independently programs the ...

You sometimes need an inexpensive VCO that can produce evenly spaced three-phase outputs over a wide frequency range. You could use tracking all-phase filters with only one oscillator, but this technique is difficult to implement and offers limited ...

If you use a function generator, you may occasionally require a sine-wave output at a higher frequency than the generator can provide. If your function generator also produces a triangle-wave output, you can use a frequency doubler to extend the ...

The original bipolar 555 timer, the NE555 , is excellent for driving a power MOSFET’s gate. Newer CMOS versions such as the 7555, LMC555, and TLC555 use less power, but they have trouble sourcing enough current to drive a gate well and can ...

The growth of battery-operated applications has put steady pressure on designers to steeply reduce their products’ operational power consumption and bring standby power as close to zero as possible by carefully managing the devices’ ...

A few years ago, I worked at a disk-drive company. We had a plating facility that required square waves to drive the high-voltage plating operation. The challenge was that the square wave's pulse width had to be variable, along with the duty ...

Plumbing a laboratory with a standard frequency makes a lot of sense if the lab uses multiple frequency counters, spectrum analyzers, and other frequency-dependent test equipment. Rather than spending time keeping all of the instruments' ...