Frequent design idea contributor Nick Cornford recently published a synergistic pair of DIs... The main theme of these articles is design techniques for audio VCOs that have an exponential relationship between control voltage and frequency...
Articles and news - 2
Can a free running LMC555 VCO discharge its timing cap to zero?
Versatile multistep resistor load bank is simple and modular
This modular resistor load bank uses a unique topology to reduce the number of switches and resistors while providing the maximum number of steps...
BJT muting switch
In general, muting and/or signal switching is done by relays, FETs or CMOS analogue switch ICs. All have limitations, but a little known technique that really doesn't look like it could ever work...
Op-amp input protection can be noisy
Most operational amplifiers have input and output electrostatic discharge protection diodes. These diodes are designed for protection from ESD damage during device testing and product assembly...
Use current-mirror biasing to avoid squegging in RF oscillators
If you've ever designed an RF oscillator, you've probably encountered squegging. Sometimes called "motor boating," squegging causes oscillators to start and stop at frequencies much lower than the frequency of interest...
100-MHz VFC with TBH current pump
Famous analog designer and author Jim Williams published an awesome design in 1986 for a 100-MHz voltage to frequency converter...
Why 45 degrees? An overview of loop stability in operational amplifiers
In operational amplifier stability, one rule of thumb is to allow 45 degrees of phase margin. Other design guidelines state that 60 degrees is best; still others say that 30 degrees is sufficient. These numbers are all attempts to ensure stable performance over a range of variables...
Active multiplexing saves inputs
Microcontrollers must often read the status of switches in control applications. A typical switch configuration uses pullup resistors on both of the switches to pull the signals high or low for the microcontroller to read...
Spice models differential stripline
Differential signaling is a common technique for obtaining high noise immunity for critical signals in high-speed digital pc-board systems. The pc board's traces, carrying differential signals, are often edge-coupled offset striplines, with the traces sandwiched between two reference planes...
A pitch-linear VCO. Part 2 - Taking it further
In this second part, we’ll look at some alternative ways of arranging things for other possible applications...
