Simulate input-offset current current mirrors
Simulate input-offset current for current mirrors
10.03.2024 Articles

Simulating the output-offset current of a current mirror is straightforward. You simply have to apply an input current, measure the output current, and calculate the difference. This output-offset current, however, is not equal to the input-offset current...

power practical positive feedback perfect PRTDs
The power of practical positive feedback to perfect PRTDs
10.02.2024 Circuits

Frequent contributor Nick Cornford recently published a delightfully clever design idea using a platinum RTD calibrated to output a 1 mV/°C signal that’s perfect for direct readout via a standard DMM…

Electromechanical damping stabilizes analog-meter readings
Electromechanical damping stabilizes analog-meter readings
10.01.2024 Circuits

Before shipping moving-coil meters, manufacturers may short-circuit the meters' terminals with a length of wire, which provides effective electromagnetic damping and results in better immunity to external mechanical vibration and shocks that can occur during transportation...

20MHz VFC take-back-half charge pump
20MHz VFC with take-back-half charge pump
09.30.2024 Circuits

Way back in 1986, famed analog innovator Jim Williams, in “Designs for High Performance Voltage-to-Frequency Converters” published his “King Kong” 100 MHz VFC. I have never seen its equal...

Take-Back-Half precision diode charge pump
Take-Back-Half precision diode charge pump
09.29.2024 Articles

Nearly four decades ago famed designer Jim Williams cataloged five fundamental techniques for voltage to frequency conversion. One of those five is reproduced in Figure 1...

Long delay timer sans large capacitors
Long delay timer sans large capacitors
09.26.2024 Circuits

There are several applications at home or industry for long delay timers. Time delays on the order of seconds can be generated using 555 timer circuits...

DIY RTD DMM
DIY RTD for a DMM
09.25.2024 Circuits

I was driven to produce the circuit in this design idea by my increasing frustration with a collection of digital thermometers, all of which claimed accuracy to within 0.1 °C but the readings of which were mismatched by anything up to a couple of degrees...

Dual-coil relay driver uses only two
Dual-coil relay driver uses only two MOSFETs
09.24.2024 Circuits

Latching relays change their states when you apply a short voltage pulse to their coils. Because these relays require no continuous coil currents to keep their states, you can save considerable power in the driver circuit...

Brute force mitigation PWM VDD ground
Brute force mitigation of PWM VDD and ground "saturation" errors
09.23.2024 Circuits

An excerpt from Christopher Paul’s “Parsing PWM (DAC) performance: Part 1 – Mitigating errors”: “I was surprised to discover that when an output of a popular µP...

Mighty 555 ESR-meter
Mighty 555 and ESR-meter
09.19.2024 Circuits

Let’s see how you can effectively double the output sink current of the plain old 555 timer...