Does anyone know of a small IC package for a "momentary latch"?

Thread Starter

durable126

Joined Feb 20, 2016
56
Does anyone know of a small ic package for a momentary latch?

For a momentary switch to turn something on and off

I know how to use one using bits, but would rather not have the headache

I have not found any ready made IC out there but I'm sure someone makes one.
anyone know of any?
 

ian field

Joined Oct 27, 2012
6,539
a latch for a pushbutton switch to turn something on and off
as opposed to a slider or toggle switch
That's a bistable, some manufacturers are producing individually packaged logic gates - there may also be individual flip-flop logic elements.

Or you could use 2 transistors and a handful of components.
 

Papabravo

Joined Feb 24, 2006
13,958
I don't think such a part exists. AFAIK there have been very few new MSI IC's introduced since the late 1980's. Everything now is FPGA and microprocessors. So how about an 8-pin ATTiny and a few lines of code?
 

pebe

Joined Oct 11, 2004
626
As Ian suggested, use a 555.

Connect pins 2&6 together. Fit a 10k resistor between those pins and V+.; that keeps the latch normally off.
Connect a momentary push button between pins 2&6 to V-.. The latch will turn on for as long as the button is pressed.
 

AnalogKid

Joined Aug 1, 2013
8,492
To turn a momentary pushbutton switch into an alternate-action function, you need a little debouncing and a toggle flipflop. Depending on the circuit voltage, you can use 7400 series TTL or 4000 series CMOS 14-pin chips. With the CD4013 you get two toggle flipflops in one package. There are specialized ICs for LED flashlights that are a single toggle ff in one SMT package, but you usually have to buy a large quantity.

ak
 

TheButtonThief

Joined Feb 26, 2011
237
Or you could just use one of these and not use electronics at all.... but what fun is that?
http://www.jpmsupply.com/product-p/70213.htm?gclid=CMC_n_eMncsCFQwPaQoduB0Beg
Maybe the OP has a specific switch/button that they would like to use and so switching function needs to be designed.

My choice would be to use a µc, the ATtiny85 is an 8 pin package and is also available in SMT. The regular package is the same as a 555 but wouldn't require any external components, just an embedded programme.
 

Lindembruck

Joined Feb 28, 2016
46
Hi!
In this link, we have a lot circuits.
I think, you will can use a Darlington in the flip flop output with a resistor but you need to upload pictures and the flip flop you have with the schematic you has tried.
 
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