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unknown LED Driver IC

davenn

Moderator
hi gang

got all these LED chasers. The flamin' manufacturer's scrapped the IC # off the chip :rolleyes:

its a 4pin DIL (ie. the same as a 555 timer) google searches turned up lots of PIC driven LED chasers. Wonder if this is a PIC or some other linear IC anyone come across a cct like this ?

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Cheers
Dave
 

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I would be fairly confident that this is a PIC microcontroller.

Probably PIC12F629.

Possibly PIC12F675.

Possibly PIC12F683.

Be aware that a replacement PIC would need to be programmed before it will do anything.

Hope this helps
 
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davenn

Moderator
hey mate

yeah the 12F629 seems a reasonable candidate even has the correct pins for power supply ;)

I mite unsolder one out of cct and see if I can read the firmware. That if they havent set the code to stop the reading of the chip. worth a crack at it

thanks
Dave
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
Moderator
Unlikely to be a PIC given the way the inductor is connected. (that's assuming the inductor is used to boost the incoming voltage)
 

davenn

Moderator
Unlikely to be a PIC given the way the inductor is connected. (that's assuming the inductor is used to boost the incoming voltage)

ok any thoughts on what else it mite be ?
I dont know of any specific LED driver chips googling such just provided lots of links to PIC drivers

Dave
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
Moderator
Looking at that circuit again, I can't see that it could be a boost regulator. Maybe the inductor forms part of a filtering circuit. If it does, then I guess it could be a PIC.

But it seems unusual to have an inductor there... And the resistor across the incoming power supply... Weird.
 
Is that a Zener diode or just an ordinary diode acting as a freewheel?
It looks suspiciously like a voltage convertor to me, earthing the inductance to get sufficient current and then dumping it into the leds, Cunning.
 
I'm sure that's a PIC, as they have the MCLR pin pulled up. Each pin can usually drive 20-25mA which is enough to drive a single LED.

The program on the PIC is likely to be VERY simplistic, just cycling turning one bit on a register, but you'd need a cheap programmer.

I can't recall exactly where I've seen that config before, but it was to do with driving LEDs from a coin cell, so I agree it's probably a booster of some sort.
 
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