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I am using HC as led driver for driving 9 2 inch and 30 1 inch leds. HC also needs a 5v as supply voltage. It gives 35 microamperes as output current per pin.
I want know I need to use HC to be connected in the input and ouput of HC while giving high voltages like 12v. Will I directly connect HC with Microcontroller to get signals and with 7 segment Led to output signals?
I want to avoid unwanted flickering in 7 segment LED that occur randomly while getting data for it through wireless mode. I need solution for this too? An HC will deliver a LOT more than 35 microamperes; without looking at the spec sheet, I would guess that it would be more like 35 milliamperes.
Allegro, and possibly others, make open collector power drivers with built-in shift registers that would be ideal. To create a non-flickering display without parallel data direct from your micro that is, one pin per display segment , the common process is a shift register, or series of registers, that is run from the processor's SPI port.
Choose a shift register that has a separate output latch, The 74HC is exactly that kind of latch. You do all the shifting, then, boom, update ALL of the output latches at the same time, then no flicker. I don't see how you would use an 74HC, at all. The OP must have misread the specs I think. A 74HC can sink and source 35mA bus driver outputs , and 25mA std output on the daisy chain output. A ' is not really useful in these applications; a ' or a ' would if you have a parallel bus.
I am not sure, but i guess the UCNA is not easy to get everywhere also it fits perfect. So if your pcb space is not critical, why not using an old combination?
The 5 V change in voltage only has to be enough to change the output from on to essentially off. I am using HC for shifting the datas coming from microcontroller. I am beginner,so I want to know,could we directly connect the microcontroller and HC and the 7 segment LED in series or any non inverters like HC should be used to control the unwanted voltage spikes and to assure the regulated,non-flickered data shift flow between LEDs.
There may be a little higher overall current, thats about the only difference. The hc and be OK to drive the 1 Inch 7 Seg. LED displays. With the higher voltage the HC will noch help.
The shift registers could be a little more sensitive to distortions than other digital circuits. So you may have a look at powersupply decoupling, ground layout and maybe signal termination for the clk line if you have a long line e. The HC will not help with voltage issues. It is no better nor worse than most other 74HC-family chips.
Not with voltage no, but if I recall, as ' is a bus driver, it has a bit more current sink and source ability than for example a basic '04 inverter.
That driver should avoid the unwanted distortions and ensure constant,proper data shift between LEDs. Tell me the basic hardware configuration or design parameters that should be considered while designing a LED circuit.
No need for a 12V driver Skip to main content. Log in or register to post comments. Go To Last Post. Level: New Member. Posts: 17 View posts. Posted by beeba : Thu. Apr 30, - PM. Fivestar widget 1 2 3 4 5. Tags: Learning and Information , General Electronics.
Posts: View posts. Posted by ka7ehk : Thu. Log in or register to post comments Top. Level: Raving Lunatic. Posted by jayjay : Thu. Posts: 1 View posts. Posted by bernard1 : Thu. Level: Posting Freak. Posted by Kleinstein : Fri. May 1, - PM. Posted by beeba : Sun. May 3, - PM. Posted by Kleinstein : Sun. Posted by ka7ehk : Sun. Posted by Jepael : Sun. Posted by jayjay : Sun. But a ' also has busdriver class outputs as i posted before.
May 7, - AM. I made a suggestion a couple of posts above. There must be hundreds of sites out there that explain how LEDs work and how design with them. You should use proper design techniques, no matter what chip you use. May 7, - PM. LED Array.
HC245 Data Sheet PDF
Artist: Laura Wilder HC245