These synchronous, presettable counters feature an inter- nal carry look-ahead for application in high-speed counting designs. The DM74LSA and. 74LS datasheet, 74LS pdf, 74LS data sheet, datasheet, data sheet, pdf, Fairchild Semiconductor, Synchronous 4-Bit Binary Counters. The LSA/A/A/A are high-speed 4-bit synchronous count- ers. They are edge-triggered, synchronously presettable, and cascadable. MSI building.
|Published (Last):||20 December 2016|
|PDF File Size:||13.41 Mb|
|ePub File Size:||10.26 Mb|
|Price:||Free* [*Free Regsitration Required]|
Sign up or log in Sign up using Google. WhatRoughBeast 49k 2 28 As further issues arise I see myself stuck once more with a dysfunctional circuit. Since you already need one section of aand there are 6 gates per IC, you simply go.
Finally, you should not count on TTL outputs driving high, as you have shown. I added a 0. In that case, invert the signals going to your LEDs. Also, have you added a 0.
So your outputs should be connected like. I have added a debounce circuit, but still to avail.
Post as a guest Name. Since you already need one section of aand there are 6 gates per IC, you simply go simulate this circuit. It’s always the simple things. That’s probably causing as much trouble as no debounce was.
Sign up using Email and Password. Sign up using Facebook. Datasehet breadboards, use a cap for each IC. TTL works much better pulling dataasheet down. So your outputs should be connected like simulate this circuit — Schematic created using CircuitLab You may object that this will provide LEDs which are on when the output is low, and off when the outputs are high, which is confusing. You can often get away with less, but as you’ve just learned, insufficient decoupling can have weird symptoms.
N 4-bit counter not counting properly – Electrical Engineering Stack Exchange
I’m still getting the same effect. Whenever I press the clock button I get all of the leds on except maybe one or two, with some flashing during the button press. Without this buffering, your switch should not work on a button push, only on a release. Oh, Ill change that and see what happens. You may datawheet that this datashest provide LEDs which are on when the output is low, and off when the outputs are high, which is confusing. For a circuit board with a ground plane, the usual guideline is at least one cap per 5 ICs.
Then I used a pullup resistor for the clear switch. I’d reduce that down to something in the nF to 1uF range.
Fairchild Semiconductor – datasheet pdf