Digital Pulse Stretcher Circuit

In one of my design i need to stretch narrow 10 ns pulses coming from photo diode after tia stage if i have to measure the pulse amplitude i have to stretch it at least by a factor of 100 in this search i have found a approach in which the circuit was using a capacitor after its feedback path but i have not understood how exactly the circuit works but when i tried to.

Digital pulse stretcher circuit.

The most basic circuit is an rcd network followed by a schmitt trigger. The diode comes from the input so that an active input always keeps the capacitor topped up. Hi i have a 5v single supply available. If the capacitor is allowed to discharge then it eventually crosses the schmitt trigger threshold and the output changes state.

This is a pulse generator circuits or standard astable multivibrator oscillator or free running circuit using ic555 timer ne555 lm555. For detecting a signal from a photodiode amplifier via uc i need to buffer and stretch a pulse which is around 5 ns wide periodic 100 200 ns and down to some 100 mvp amplitude and dc biased somewhere between 1v and 2 5v. A digital pulse stretch circuit for adding a predetermined amount of time to the duration of the input pulse of a wand type or magnetic card reader the input pulse having a rising edge and a. Monostable or one shot or pulse extender circuit when the circuit is turned on the output is low and a brief negative pulse on pin 2 will make the output go high for a period of time determined by the value of r and c.

Ic 555 is popular easy to use small size with 8 pins. It is combining analog and digital chip. In one of my design i need to stretch narrow ns pulses coming from photo diode after tia stage if i have to measure the pulse amplitude i have to stretch it at least by a factor of 100 in this search i have found a approach in which the circuit was using a capacitor after its feedback path but i have not understood how exactly the circuit works but when i tried to. Because the pulse was so short driving the led directly even with a transistor driver created a pulse too short to be seen well.

If pin 2 is low for longer than this period the output will remain high while pin 2 is low and immediately go low when pin. The r and c are in parallel to gnd. The pulse detecting electronics usually has a pulse stretcher circuit so that even very short pulses become visible on the led.