HH004F LED driver

HH004F LED driver circuit

HH004F is a low power integrated boost converter IC in a TO-92 package, look exactly like a small transistor.

Though it’s quite a uncommon and undocumented IC, but you may find it occasionally in some LED torches. The IC is available in many different numbering and marking.

I got one of them, and decided to draw the schematic and build a prototype.

 

HH004F based LED driver

This IC is typically used as a low power LED driver with 1.5V input voltage, here’s the schematic.

HH004F LED driver

So, it’s pretty simple, just the HH004F IC, a 3.3uH inductor, a LED, a switch and a 1.5V battery.

Here’s the pin out of the IC.

hh004f pinout

I decided to build a quick prototype after salvaging the IC from a torch, below the picture of my prototype.

hh004f

The value of inductor is not so important, anything between 2.2uH to 10uH should work.

So, that’s all for this short post. Don’t forget to share your thought through the comments.

8 Comments

    • Chinmoy Mitra

      Forgot to mention that the price mentioned in my previous post is for 50 pcs of the IC.

      • Arnab

        Then it’s dirt cheap, I’ll order some in future.

  1. Curt Simms

    Arnab, thanks for posting! I found this “transistor” (marked HH004F) in a 3-LED stick-on closet light (2 AA batteries).

    I couldn’t for the life of me figure out how this “transistor” and “resistor” were doing anything. It never occurred to me it was an IC and an inductor (0 ohms, thought it was shorted).

  2. Sean McHugh

    Do you believe that 250mW should be the limit?

  3. Julio Cesar

    Saludos, aún no entendí que hace este i.c. lo encontré en una pequeña linterna de dos pilas de 1.5 voltios en serie, serían tres voltios, estos tres voltios, manejan bien los tres led en paralelo, por eso no entiendo la función del i.c.

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