Articles - Analogue Design - 4

Although current mirrors and circuits such as the Howland current source are taught in analog circuit courses, a surprising number of engineers tend to think exclusively in terms of voltage when defining the output of precision analog circuitry. ...

While measuring op-amp input capacitance, what should you focus on? The answer is that you must ensure the measurement accuracy isn’t degraded by the stray capacitance and inductance of the PCB or test setup. You can minimize these issues by ...

In process-control applications requiring discontinuous controllers, the most elementary choice is a two-position-mode or on/off controller. A typical example of such a controller is a space heater. If the temperature drops below a setpoint, the ...

A switched-mode power supply (SMPS) employing peak current-mode control (PCMC) requires a ramp signal to slope-compensate the inner (current) control loop. Slope compensation stabilizes the current loop, which would otherwise exhibit subharmonic ...

ADCs with differential inputs are becoming increasingly popular. This popularity isn't surprising, because differential inputs in the ADC offer several advantages: good common-mode noise rejection, a doubling of the available dynamic range ...

The simple circuit shown accomplishes full-wave signal rectification with only one transistor (Fig. 1). This is done by exploiting the “gain reversal” phenomenon exhibited by a saturated bipolar transistor. This circuit will find ...

The human ear is very good at detecting noise or missing cycles in a waveform, and since we have two ears, we can monitor two signals at once. I recently repaired an older lab instrument containing a quadrature encoder made with an incandescent ...

When you design for electronics applications, such as sensor or amplifier bias supplies or special waveform generators, a controlled constant-current source or sink circuit can serve as a useful building block. These circuits exhibit high ...

You sometimes need to measure a small signal in the presence of a large common-mode signal. Traditional instrumentation amplifiers that use two or three op amps in their internal structure find common use in these applications. The circuit in ...

Part 1 Preserved DC Precision In a typical operational amplifier circuit, a portion of the output is fed back to the inverting input (Figure 9). Errors that are present on the output which were generated in the loop are multiplied by the feedback ...