[SOLVED] Is there any fully transparent flip flop with just 2 pins?

[hans512]

Hello
Im newbie.

Im looking for transparent flip-flop element (aka "latch") that can be used without clock signal, but I would like to use only 2 pins (one for input and second for output - WITHOUT using additional pins for power or grounding).

Is it possible?

Thank you.

 

[keith1200rs]

A latch with no clock signal and no power & ground? No, it is not possible! You need 5 pins including power & ground.

Keith.

 

[hans512]

Can it be done by some alternate element then (but still with simple 2 pin operation)?
I just need to divide frequency by half.

Thank you

 

[keith1200rs]

Yes, you can have one input, one output and two power pins then - making 4 in total. If you were using a D type flip-flop then you could connect the /Q to the D and the clock would be the input. I don't think you can devices with just those pins, but you could connect a normal device (JK or D type) to operate in that way.

Keith.

 

[Pjdd]

Think. The input frequency is a train of voltage pulses. A voltage, by it's very nature, is the potential difference between two points. The input to the hypothetical flip-flop has to have two points to enable it to recognise the input as a voltage. Same thing for the output.

That said, let's let our imagination run wild. If the incoming pulse train is in another form of energy, like light, and the input of the FF is a photosensitive device, and the output is another light emitter which is pulsed at half the frequency of the incoming signal after being divided by the FF. If the input to the subsequent stage is another photosensitive device, then we have a frequency divider without any electrical contact between the signal source and the following stage. Let's go even wilder and mentally devise an interface using ultrasound, RF, magnetic field, etc. and we have the same function as with light.

But I don't think this is the kind of thing you had in mind. With such a scheme, the FF unit will have to have its own power supply and a reference point anyway.

 

[hans512]

Thank you guys!

So basically this:

**broken link removed**

is the most minimal and closest solution to my idea yes? And clock can be input signal itself then?

 

[keith1200rs]

Yes, that will give you a divide by 2. You can also do it with a JK flip flop, either the same way or connecting J&K both to logic 1.

Keith

 

[hans512]

Thank you guys

 

[dick_freebird]

If the supply were input-pumped I could see you getting by
with 3 pins (input, ground, output) and a dynamic DFF.
But you're going to demand a lot of input power and
allow very little output power, like that. Probably a poor
way to go, generally.