Circuits & Schematics Analogue Design

Few methods for analog to digital conversion are more “mature” than the classic combination of a voltage-to-frequency converter (VFC) with a counter. VFC digitization is naturally integrating, so good noise rejection is inherent, as is ...

It’s interesting, useful, and fun that basic electronic topologies often turn out to have utility in multiple and surprisingly different applications. Figure 1 shows an example of such a circuit. It’s a charge pump voltage inverter ...

This Design Idea mates a precision current source IC with precision difference amp chips to create a programmable current source or sink. The resistor-programmable current source/sink in Figure 1 illustrates the basic topology, taking advantage of ...

In many applications, there are requirements of low power, high performance differential amplifiers to convert small differential signals to a readable ground referenced output signal. Input voltages at two inputs usually share a large common-mode ...

Figure 1 shows two large-signal- measurement methods. The first uses a two-resistor voltage divider and an output buffer, and the second comprises an attenuating inverter and a high-value input resistor. Both of these approaches introduce ...

Several years ago we were developing a clamp-on photometer, a hand-held instrument that could be clamped onto a communications optical fiber to indicate the presence of light, its direction of travel, and the presence of combinations of ...

When a system's specifications call for a lowpass filter with a steep frequency-cutoff characteristic, an engineer can opt for a “brick-wall”- filter design that features a sharp transition band. For example, in an FM ...

Junction field-effect transistors (JFETs) usually require some reverse bias voltage to be applied to a gate terminal. In HF and UHF applications, this bias is often provided using the voltage across the source resistor R S (Figure 1). Figure 1. ...

Self-heated transistors used as thermal air flow sensors are a particular (obsessive?) interest of mine, and over the years I must have designed dozens of variations on this theme. Figure 1 illustrates one such topology seen here (Reference 1) ...

Integration of analog circuitry with digital logic often requires the addition of an extra supply rail or two. The excellent PSRR of precision op-amps (typically 100 dB) makes them unfussy about power rail variations. This simplifies power supply ...