74LS74N Datasheet, 74LS74N PDF, 74LS74N Data sheet, 74LS74N manual, 74LS74N pdf, 74LS74N, datenblatt, Electronics 74LS74N, alldatasheet, free. The SN54 / 74LS74A dual edge-triggered flip-flop utilizes Schottky TTL cir- cuitry to produce high speed D-type flip-flops. Each flip-flop has individual clear and. This device contains two independent positive-edge-trig- gered D flip-flops with complementary outputs. The infor- mation on the D input is accepted by the.

Author: Dairr Kajijora
Country: Morocco
Language: English (Spanish)
Genre: Literature
Published (Last): 19 November 2011
Pages: 428
PDF File Size: 12.76 Mb
ePub File Size: 5.98 Mb
ISBN: 902-2-22219-629-6
Downloads: 71684
Price: Free* [*Free Regsitration Required]
Uploader: Moogutaur

I’ll amend my question to make it more 74ls74j. Sign up using Email and Password. Adding a 5K or so pull-up resistor is good practice, but usually not necessary.

74LS74N Datasheet

I connected pin3 clock to ground through a 10k resistor in addition to having the push button from power. Because of this, the clock is seeing multiple pulses when you intended on making only one.

Logic ICs should never have floating inputs. And do you have a 0. I get the feeling that I connected something wrong initially. The traditional solution for switch inputs is to put the switch between the input pin and ground. You can’t have floating inputs. Note the pull up resistors at the inputs of both NAND gates. Home Questions Tags Users Unanswered. Since the inputs source current, they must be pulled Low with a small under 1K resistance to be seen as a logic Low.

This basically means the connections in the button open and close very fast more than you would like. Including the inverse-clear and inverse-set for the half of the you are using. Sign up using Facebook. By using our site, you acknowledge that you have read and understand our Cookie PolicyPrivacy Policyand our Terms of Service. Post Your Answer Discard By clicking “Post Your Answer”, you acknowledge that you have read our updated terms of serviceprivacy policy and cookie policyand that your continued use of the website is subject to these policies.


WhatRoughBeast 49k 2 28 To a circuit, this means switch is on, and switch is off and this happens at a faster than expected rate for a short time.


If using a switch to ground you need a pull up resistor again, say, 10K ohms to Vcc. Email Required, but never shown. Is there a way to test it with a simpler configuration? It’s not bad for experimentation purposes, but if later on you decide to never use the set or clear operations of the chip, you could tie them directly datasheeet power.

You need to de-bounce your switches in order to get predictable results. Is there a point where I may consider the chip is not functioning properly? Post as a guest Name. When the button is pressed, the capacitor is shorted until the button is let go, then the capacitor charges up.

A 74LS74 has a nominal rating of 16 mA when low.

Make sure by power you mean the positive side of a 5 volt DC source. The input of digital circuits needs to be either on or off.

Sign up or log in Sign up using Google. The resistor is used to provide a default logic level to the clock, which in this case is logic level zero since the resistor is connected to ground. CMOS parts 74ACxx, 74HCxx, and others with a “C” are CMOS and have very high impedance inputs – they can be used with high value pull-up or pull-down resistors – but ALL inputs must be connected somewhere, else they may be seen as “maybe” levels, and cause the chip to draw excessive current.


But instead of flipping from Q to Q’ when I push the button, it just blinks rapidly. Also, connect a resistor from 74lx74n clock input pin 3 to ground.

Digital circuits are fast and see the bounces. The reason is that the input current is much less when high than when low, so less power is wasted on the unused function.

I tried the arrangement you outlined. Better practice is to connect the switch between input and ground, to give a solid Low when the switch is closed. The inputs of bipolar TTL logic 74xx, 74LSxx, and others without a “C” in the middle of the part number source current, and will normally appear as a High when not connected. Try increasing the resistors to ohms or so.

I tried unsuccessfully to make an SR flip flop out of it too. For bipolar Dstasheet, such as the 74LS74 and the OP mentions, you would need a very low value pull-down resistor as the inputs source current.

As WhatRoughBeast pointed out, you need to apply this practice to all inputs. I successfully made an SR FF.

iPhone X