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 ...
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 ...
The simplest model of a battery comprises an ideal voltage source that connects in series with a resistance whose value often a few milliohms depends on the battery's electrochemical condition and construction. If you attempt to use an ordinary ...
Some op amps, such as the AD8041 from Analog Devices and the EL5100 from Intersil, provide a disable pin, which allows you to parallel the outputs of several op amps for video multiplexing. In addition to this multiplexing, you can also use the ...
An audio volume-unit meter displays peak-related audio amplitudes to aid in accurately setting recording levels or for displaying an amplifier's operating conditions. A simple diode and capacitor network provides a classic volume-unit ...
A number of single-chip VGAs variable-gain amplifiers are available today. Unfortunately, they all have drawbacks, such as high noise, 55 V limit, low input impedance, or nonlinear gain/frequency characteristics. The circuit in Figure 1 is a ...
Some amplifier applications require clamping or limiting due to large, sporadic signals appearing at the amplifier input. Clamping these errant signals protects the amplifier and other sensitive downstream circuitry. It also improves overdrive ...
Comparators are great at turning little signals into large digital outputs. In the example described here, a friend wanted to detect the presence of a small 60-Hz AC signal centered on 2.5 V DC. When the AC is absent (beneath the specified ...
In adjustable, frequency-selective RC networks, the reciprocal of an RC product, ωC = 1/RC, determines the corner frequencies of the network. If the adjustable elements are potentiometers with a linear-control characteristic that is, taper ...