The MC74HCA is identical in pinout to the MCB. The device inputs are compatible with standard CMOS outputs; with pullup resistors, they are. 74HC Datasheet, 74HC PDF. Datasheet search engine for Electronic Components and Semiconductors. 74HC data sheet, alldatasheet, free. 4 Sep nS catch circuit using a basic 74HC/74HC monstable is very straight forward to give an input to the PIC. Can post an LTSpice sim.
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Only a few lines of code.
or Timer as a One-Shot
This is a nuisance for PCB development as this forms the letter H under the chip on the board which prevents wires from running through. No, create an account now. Feb 6, 3. I also don’t want to leave the inputs floating as unpredictable results can happen. You bias the reference minus some from the incoming signal. 744hc121 alternative to DS Posted by stoopkid in forum: View attachment You are at 5V and minimum trigger width is ns. I guess jumper wires are my only real option then.
Invest the time to learn how to fix this in software, you will not regret it.
There are many ways you can implement delays without going into a dedicated delay loop. I tried the CD chip and for the application it works perfectly, however to pull things off, I have to tie 4 items high from the chip itself Feb 9, I have a high-speed microcontroller application and I want to hook up a gpio pin on it to an output of a big delay external timer so that I don’t have to hold up the microcontroller cpu just to count a long delay.
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Can post an LTSpice sim when I get around to it.
Feb 6, 1. Discussion in ‘ Digital Circuit Design ‘ started by testuserabcdefFeb 6, Mikebits 744hc121 Member Sep 7, Playstation 1 motherboard housing fell off, help! Click here to register now.
74HC Datasheet, PDF – Datasheet Search Engine
This runs all the time. The perfect approach for me is two monostable multivibrators, because one will be 74hc12 for the pin and another to refresh the clock on an external flip-flop connected to the micro for other purposes.
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detect pulse of 140ns and 50mv.
Nov 23, 8, 6, You must log in or register to reply here. Apr 11, 3, 1, OpAmp circuit for temp sensing using diodes Started by Elerion Today at 1: Started by chemelec Today at 4: You May Also Like: Then, in the interrupt routine have a variable which is your virtual “timer” – you can have as many of these as you like as you like.
Feb 7, Alternative to Xbee Posted by bencbrown91 in forum: Try a high-speed opamp. When the register reaches zero – the time delay is complete and you stop decrementing. I don’t want to use another microcontroller to make the timer itself. Feb 6, Jan 6, 3, 1, Mikebits Well-Known Member Sep 6, I don’t know how long a pulse needs to be to guarantee it triggers an interrupt? On the analogue side, a simple high speed op-amp comparator will do.
Feb 6, 4. When the flag is clear timer stoppedset the register to your timing value.
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The LM is too slow for amplifying a nS pulse. Feb 6, 7. Check Out Cornell’s Wireless Biometric Pen Drive Prototype Two engineers from Cornell have combined the functionalities of a wireless pen drive with a biometric data security system, can they make it commercially viable? Apr 4, Welcome to our site!
Nice if it can be every millisecond, for example. Hi, i want to detect a pulse with ns and 50mV amplitude.