Switching regulator efficiently controls white-LED current
Switching regulator efficiently controls white-LED current
05.18.2022 Circuits

A few years ago, manufacturers specified their white, but dim, LEDs for a maximum forward-current rating of 20 mA. Today's white LEDs deliver more light and thus must operate at ever-higher bias currents...

Two-wire four-by-four-key keyboard interface saves power
Two-wire, four-by-four-key keyboard interface saves power
05.16.2022 Circuits

You can use a microcontroller that includes an ADC to design a two-wire-plus-ground keyboard interface. For example, you can use a resistive voltage divider to identify a pressed key...

Flusso launches world smallest air velocity
Flusso launches world's smallest air velocity sensor
05.12.2022 News

Flusso has announced another breakthrough for the flow sensing market: the world’s smallest air velocity sensor. The FLS122 has a footprint of just 3.5 by 3.5 mm...

Latching power switch uses momentary-action pushbutton
Latching power switch uses momentary-action pushbutton
05.12.2022 Circuits

Most inexpensive pushbutton switches, particularly pc-board-mounting and membrane types, have momentary action. Latching types are often larger and relatively expensive...

Tapped inductor boost regulator deliver high
Tapped inductor, boost regulator deliver high voltage
05.11.2022 Circuits

When you face the task of generating a regulated voltage that's higher than the available power-supply voltage, you may consider a boost regulator. Although a boost converter can in theory generate almost any voltage that's higher than its input, practical considerations limit the output to approximately eight times its applied voltage...

Off-the-shelf watchdog serves pinch
Off-the-shelf watchdog serves in a pinch
05.10.2022 Circuits

The performance of the watchdog circuit may not match that of a dedicated watchdog circuit, but this circuit is helpful when the only watchdog in the lab doesn’t meet your design’s temperature requirement and when you are in a hurry to finish a prototype...

Comparator has independent trip voltages
Comparator has independent trip voltages
05.06.2022 Circuits

For an inverting amplifier with hysteresis, resistors RA, RB, and RF determine the crossover voltages. Unfortunately, using three resistors to set the upper and lower trip voltages creates a dependence between the two trip voltages: It’s impossible to set one voltage without affecting the other...

Constant-Current Source Creates Slope-Compensation Ramp SMPS
Constant-Current Source Creates Slope-Compensation Ramp in SMPS
05.03.2022 Articles

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

Generate Positive Negative Voltage by Combining
Generate Positive and Negative Voltage by Combining Two DC Sources
04.28.2022 Articles

Using two unipolar dc supplies in an anti-series configuration is another approach for generating positive and negative voltage – and one that doesn't suffer from power interruption...

Circuit yields ultralow-noise VGA
Circuit yields ultralow-noise VGA
04.27.2022 Circuits

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 iis a 16-step, ultralow-noise VGA that solves many of these problems...