Circuits & Schematics - Analogue Design - 6

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 ...

The circuit in Figure 1 is a single-supply version of a programmable Schmitt trigger, or a comparator with hysteresis. A comparator, A1, and a digitally programmable potentiometer (DPP1) are used for the function. The lower (V LL ) and upper (V UL ...

The challenge of improving analog/digital accuracy by preventing amplifier saturation in systems supplied with only a single logic-level power rail has been receiving a lot of activity and design creativity recently. Voltage inverters generating ...

Differential temperature measurement is a handy way to quantify the performance of heatsinks, thermoelectric coolers (TECs), and thermal control in electronic assemblies. Figure 1 illustrates an inexpensive design for a high-resolution differential ...

Conventional thermostats are based on separate temperature sensor and heater devices with means for feedback between them. But in some recent EDN design ideas (DIs) we’ve seen thermostat designs that meld the functions of sensor and heater ...

Evaluating analog switches, multiplexers, operational amplifiers, and other ICs poses challenges to IC-test engineers. A typical test scenario requires application of a test or forcing voltage to a device's input and measurement of any ...

Avoiding op-amp output saturation error by keeping op-amp outputs “live” and below zero volts is a job where a few milliamps and volts (or even fractions of one volt) of regulated negative rail can be key to achieving accurate analog ...

Awhile back I published a simple design idea for a thermal airspeed sensor based on a self-heated Darlington transistor pair ( Ref. 1 ). See Figure 1. Figure 1. Older design idea with self-heated Darlington thermal airflow sensor. In the circuit, ...