Free Circuit Diagram

In some PLL application, sometimes we need to provide lock indication when the PLL is in locked state. The simplest one is binary indication, 0 or 1 to correspond with lock/unlock condition. This  condition should be easy to be presented with a LED lamp. The schematic diagram  shows a lock-detection scheme [...]

The circuit below is a schematic diagram of a fast pulse detector. At 100 ns  or wider pulse width, the detection should be error free. At 60 ns pulse width,  the detection error should be under 10%. This circuit should be used to detect at least 100 ns wide pulse to ensure an [...]

Pulse position modulator can be easily built using 555 IC. Here is the schematic diagram of the circuit: Pulse position modulator modulate the on-period while keeping the fixed off-period. Pulse position modulation might substitute pulse-width modulation in some application. The main difference between pulse position modulation (PPM)  and pulse width modulation (PWM)  is [...]

Pulse width modulator produce a PWM signal, a pulse with a constant frequency but with the duty cycle vary according to a modulating signal. Here is the schematic diagram of pulse width modulator circuit using 555 IC as the active component: This pulse width modulator circuit need external pulse train input to trigger [...]

This is a Programmable Levels High Speed Pulse Generator circuit. This circuit consist of Lilliputian dimensions associated with the sub-micron geometries of many analog and most digital processes also advanced CMOS logic gates or analog comparators. Here is the circuit : The advanced CMOS logic gates or analog comparators is used to create faster [...]

This circuit detect the amplitude of audio signal, suitable for audio level detection that demand for high precision. Amplitude detection or signal envelope detection is usually implemented using a peak detector. An ideal amplitude detector give continuous level at any time because the amplitude of a sine signal (every signal can be seen as sine [...]