I need a specific IC that works as a toggle switch

Thread Starter

spikespiegelbebop

Joined Nov 30, 2021
13
Please take a look at this image:

1638329553412.png

I'm in need of creating a toggle switch (or whatever name it receives) that works with one push button, so I created this illustration to exemplify what I'm trying to achieve.
I have two different RGB signals, one accompanies a 5v power supply, the other one accompanies a blanking signal. What I need to achieve is switching between the two, because the tv's jungle chip can only accept one RGB signal, thus why I need to switch between them. If I press the push button, RGB 1 signal will pass through, along with the 5v, but RGB 2 along with the blanking signal will be fully disabled, and vice-versa. I'm trying to achieve something that could be done with a SPDT switch, but I'm trying to do that with an IC.

Things to consider:
- The IC does not know what's rgb 1, rgb 2, blanking, 5v, it's only function is to let the electric impulses pass to the other side after switching between them.
- The IC should have its own voltage supply.
- I'm not asking for a circuit diagram or something, I just need to know which IC or ICs could be used for the task.

Well I tried to make this as simple as possible, If that's not clear enough, please ask and I'll clarify any questions.
 

Ramussons

Joined May 3, 2013
1,147
You are not likely to find such an IC, or even fabticate one from Transistors and Resistors.
The culprit is the +5 Volts which is NOT a standard for any Video signal.
I presume that the Blanking includes the Sync of -0.3 volts.
 

Thread Starter

spikespiegelbebop

Joined Nov 30, 2021
13
You are not likely to find such an IC, or even fabticate one from Transistors and Resistors.
The culprit is the +5 Volts which is NOT a standard for any Video signal.
I presume that the Blanking includes the Sync of -0.3 volts.
The 5 volts is the right voltage that goes inside the blanking terminal in the jungle. I'm sure of it.
 

MrSalts

Joined Apr 2, 2020
835
Not sure about the NC switch in your diagram (perhaps you could invert the input signal), but take a look at the CD4066.
The Cd4066 is a good idea for an IC switching analog signals - but - probably not in this case. The on-resistance of each switch is about 150 ohms. That is a problem with RGB signals that are terminated with 75 ohms. The cd4066 would make a voltage divider and cut the voltage by 66% and that may not be acceptable for the connected devices.

I would solve this with a stack of 5v small-signal relays controlled by a switch connected to flip flops and those controlling a small transistor that can control the coil of each relay.
 

Thread Starter

spikespiegelbebop

Joined Nov 30, 2021
13
I thought about the current being reduced, but expected something around 10ohms or so... Anyway, can you show me any sample of the the relay scheme?
 

AnalogKid

Joined Aug 1, 2013
9,614
Maxim (now part of Analog Devices) and Linear Technology (now part of Analog Devices) both have a long history of video mux devices.

ak
 

MrSalts

Joined Apr 2, 2020
835
I thought about the current being reduced, but expected something around 10ohms or so... Anyway, can you show me any sample of the the relay scheme?
Something like this. The chip is a simple D-type flip-flop if you are looking for a push button. If you want a toggle switch, then it becomes stone simple. Just connect all the gates of the mosfets to a switch that connects to your 5v+ supply (no IC needed)

here is the momentary push button version.

96C6902C-BDE2-47A4-B5D5-EE8AF70BCAE1.gif
 

AnalogKid

Joined Aug 1, 2013
9,614
If the flipflop is a CMOS part, you can eliminate all of the 100 and 100K resistors.

Also, the debounce time period is only 10 microseconds, which is too short to do any good.

1. Increase the 1 nF capacitor (reference designators - ?) to 0.1 uF

2. Increase the 10 K resistor to at least 220 K

Other combinations will work just as well, such as 0.33 uF and 100 K. The time constant is not critical, but should be somewhere in the 20 ms to 100 ms range as a start.

Crutschow has a nice circuit that puts the timing resistor in the feedback loop. This eliminates the capacitor-charging current spike through the switch.

ak
1638369079220.png
 
Last edited:

crutschow

Joined Mar 14, 2008
28,474
Here's a toggle circuit that uses a delay in the D feedback so that the FF ignores any switch-bounce after the first pulse.
It doesn't generate a large current spike through the push-button contacts as some other simple debounce circuits can do.

1638369416458.png
 

AnalogKid

Joined Aug 1, 2013
9,614
There is no SPDT switch in post #1. I thought you were asking about an electronic version of the 4PDT switch arrangement you show.

ak
 

AnalogKid

Joined Aug 1, 2013
9,614
Here's a toggle circuit that uses a delay in the D feedback so that the FF ignores any switch-bounce after the first pulse.
It doesn't generate a large current spike through the push-button contacts as some other simple debounce circuits can do.
HEY - I just said that. AND, gave you credit.

ak
 

djsfantasi

Joined Apr 11, 2010
8,062
Guys, isn't this too complicated for something that's just supposed to replace a SPDT switch?
Have you at least looked at the CD4066 that I recommended in the first response? Using two chips for every four signals will give you an SPDT switch. I’m not sure if there is an analog SPDT switch, but it can be constructed from two SPST switches, by inverting the select line to the second chip.
 

eetech00

Joined Jun 8, 2013
2,786
Please take a look at this image:

View attachment 253923

I'm in need of creating a toggle switch (or whatever name it receives) that works with one push button, so I created this illustration to exemplify what I'm trying to achieve.
I have two different RGB signals, one accompanies a 5v power supply, the other one accompanies a blanking signal. What I need to achieve is switching between the two, because the tv's jungle chip can only accept one RGB signal, thus why I need to switch between them. If I press the push button, RGB 1 signal will pass through, along with the 5v, but RGB 2 along with the blanking signal will be fully disabled, and vice-versa. I'm trying to achieve something that could be done with a SPDT switch, but I'm trying to do that with an IC.

Things to consider:
- The IC does not know what's rgb 1, rgb 2, blanking, 5v, it's only function is to let the electric impulses pass to the other side after switching between them.
- The IC should have its own voltage supply.
- I'm not asking for a circuit diagram or something, I just need to know which IC or ICs could be used for the task.

Well I tried to make this as simple as possible, If that's not clear enough, please ask and I'll clarify any questions.
Might try a couple of these:
https://www.maximintegrated.com/en/products/analog/analog-switches-multiplexers/MAX4674.html

4-SPDT switches, Low RDSon.

Use a D-Type FF to toggle the switches (as mentioned in previous posts).
 
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