Circuits & Schematics Oscillators - 4

Here is a simple frequency doubler circuit that produces a square wave output with a precise 50 percent duty cycle. There are similar circuits in the literature [References 1, 2, 3] which require adjustments or selection of some components to set ...

A fixed-frequency signal generator that can produce outputs simultaneously at multiple phases such as 45 , 90 , 135 , and 180 is sometimes needed for testing multi-channel analog-to-digital converters (ADCs), analog filters, sample/hold circuits, ...

Resonant power supplies are popular because of high efficiency, low noise, and compactness. You can implement a resonant buck or boost converter using a single switch. The regulation of the output in such a converter derives from using a constant ...

A previous Design Idea describes an astable multivibrator that gets hysteresis from the positive feedback stage using a technique you can characterize as positive-capacitive feedback ( Reference 1 ). It creates hysteresis by a charge transfer to ...

Many designs exist for logic-based astable multivibrators, one of the simplest being an RC feedback loop around a single inverting Schmitt trigger inverter (Figure 1). The output charges the capacitor to the upper switching threshold, at which ...

The circuit in Figure 1 is an edge-triggered monostable circuit, based on a previous design of an edge-triggered parabolic-pulse generator ( Reference 1 ). This circuit involves a simple but significant modification of the earlier generator by ...

The circuit in Figure 1 is a variation on the familiar integrator/comparator triangle-wave oscillator, which you typically implement with two op amps. An integrator and a comparator connect in a positive-feedback loop; the comparator drives the ...

Nonlinear systems often need to become linear to be useful, and the circuit in Figure 1 provides a nonlinear sawtooth pulse for a PWM (pulse-width modulator) that can compensate for nonlinearities in sensors, controllers, or systems. The circuit ...

A current-feedback amplifier is a well-known component with many uses. Its basic block diagram shows that its input stage is a voltage follower in practice, a symmetrical emitter follower (Figure 1). The configuration samples the output current, ...

Experimenting with an HF oscillator, I needed to control the varactor diode voltage in precise increments over a 2 V-10 V range. A buffered potentiometer was the obvious choice, and connecting two pots in series to give coarse/fine control (or ...