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It's new for me to actually ask a question here instead of only reading which I did appreciated a lot in college. I have a background in mechanical engineering and do have some (low level) experience with electrical engineering. Currently I'm stuck on what looks to me a pretty simple circuit.

What I need for a project is a CR2032 powered LED that has two modes -> solid and blinking. It has to cycle through these functions by using a single switch. The first time the switch (sort of toggle switch) makes contact the LED is powered ON solid. If the switched is released again the LED starts blinking for 3-5 seconds. From that stage I would like to have two options either it completely switches OFF after 3-5 seconds or in the case the switch makes contact again (within these 3-5 seconds) the LED remains blinking. Switched OFF again and it stays OFF.

I've done quite some research and I've seen similar systems using a 555 timer. However the most simple solution I've found was a small bike light sold here in Amsterdam. This system only has an IC, two resistors and a capacitor -> LED series resistor and debounce. It is powered by two CR2032 in series. As this is a battery powered bike light it must also be energy efficient and cheap. Unfortunately I cannot find anything about the 5 legged IC (TS6536B) on the internet. So I was wondering how this works and if I could use anything similar for my project. Any help on how to find the specifications of this IC or how to approach my design in general would be greatly appreciated.

enter image description here

schematic

simulate this circuit – Schematic created using CircuitLab

enter image description here

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    \$\begingroup\$ Niek: You stated that you could not find any info about the TS6536B IC on the internet. Yet, you seem to imply you know it is a microcontroller. Is this your assumption or a fact? \$\endgroup\$ – FiddyOhm Feb 27 '17 at 10:58
  • \$\begingroup\$ Hi, you are right I made an assumption there. I changed the text. \$\endgroup\$ – Niek Amsterdam Feb 27 '17 at 11:02
  • \$\begingroup\$ This IC is most likely specially designed for this purpose. All the funcionality is inside that chip. \$\endgroup\$ – Chupacabras Feb 27 '17 at 11:22
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    \$\begingroup\$ Not convinced you have the circuit correct, you show C1 as being short circuited. I don't think the trace passes under the chip to the other pin. \$\endgroup\$ – JIm Dearden Feb 27 '17 at 11:31
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    \$\begingroup\$ Sounds like the perfect job for a little low power MCU. \$\endgroup\$ – Andy aka Feb 27 '17 at 11:43
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Option 1: Small MCU

  • ATTiny
  • PIC10, PIC12

Option 2: Recycling

Purchase a bike light or keychain light on Aliexpress with the features you need for $1. Desolder the chip and use it in your project.

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The simplest would be to get rid of that resistor. Your led is likely to be able to take in far more current than your batter is able to supply.

If the led is indeed fragile, put a resistor plus a free wheeling diode in serial with the led. Esspecially making the whole thing into a smps.

Pick a sot23 mcu and you are ready to go.

Parallel spare pins for additional current drive.

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Have you had a look at following ones?

LED driver 1,
LED driver 2

or this list.

These are LED drivers in SOT23-5 package, and very low off and quiescent current.

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    \$\begingroup\$ You have managed to post hyperlinks as code text. There is a button on the editor toolbar for links. Note that link-only answers are not recommended and that some explanation of your solution would improve your answer. \$\endgroup\$ – Transistor Aug 6 '18 at 10:05

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