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This night light LEDs circuit has three 4 positions:

  • off
  • fast blinking
  • slow blinking
  • LEDs always on

Front Back

The big central component is a switch.

I was wondering what IC drives the LEDs ? From what I can read on the PCB, I expect:

  • PY55 to be the LED model
  • 7340 to be the integrated circuit

However I couldn't find any reference for a 7340 IC online.

What IC drives the LED ?

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The chip is under the white "blob" between the PY55 and 7340 text on the PCB.

As the LED strip also says PY55 indeed the PY55 refers to the LED strip.

The 7340 can also just be the modelnumber of the PCB. It is uncommon to print an IC type number on a PCB especially when the package is a "COB" (Chip on Board) like this one.

The chip is either a dedicated chip designed for this type of application

or

it is a cheap micro controller that is programmed to perform this function.

There are microcontrollers you can buy for 3 cents, see this EEVBlog video

At that price it makes little sense to use something else.

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It's a "chip-on-board" - the IC is glued to the board, the bond wires attached, and then sealed with resin. It reduces the cost, as you don't pay for the package. Have a look at a calculator or similar. Unfortunately it's very difficult/impossible to find out out what the actual IC is, as they're likely to be custom or specialised and not generally available or marked. The numbers you refer to are (probably) not part numbers, just internal references.

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    \$\begingroup\$ Ah, I see. You thought this would be an off the shelve IC. Thanks @awjlogan ! \$\endgroup\$ – Charles Jan 10 '19 at 10:22
  • \$\begingroup\$ You're welcome @Charles \$\endgroup\$ – awjlogan Jan 10 '19 at 10:44

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