ADP1612 output equals input voltage

I'm using an ADP1612 to take 3VDC and boost it to 12VDC. So I implemented Figure 44 on page 17 of the ADP 1612 datasheet, and I had an experienced  friend do the soldering.

The problem is, I only get 3VDC on the output.  I apply 3V to the Enable line to activate the regulator, and I can see the current increase on my power supply. But the output just seems to equal the input voltage.

Has anyone else had this happen? Or do you know of what simple thing I'm likely overlooking?

Thank you!

  • Hello, Awann.

    Good day! Did you exactly follow the circuit and the components provided on the said figure? Please provide the input/output requirements of your application.

    Please double-check the layout of your board as well.

    Regards,

    Migs

  • Hi, thanks for answering.

    Here are a some of the parts I used:

    1    P86.6KCCT-ND                        Panasonic - 86.6k Ohm 0805 resistor

    1    Already have                            10k Ohm 0603 resistor (up to 0805 when we do another board spin)

    1     DFLS220LDICT-ND                 Diodes Inc - Shottky diode 20V, 2A

    1    732-1043-2-ND                         Wurth - 10uH 1.5A Inductor

    1    490-1499-1-ND                          Murata - 1800pF 0603 capacitor

    1    P22.0KCCT-ND                         Panasonic - 22k Ohm 0805 resistor

    They seem like they should work according to their ratings. 

    This it's going to be used in a 3V battery powered system, but for this early stage testing I'm powering it directly with a DC supply. 

    I'm fairly sure it's laid out correctly. It's a dead bug setup, so it's a little hard to see, but I can include some pictures if you like.

  • 0
    •  Analog Employees 
    on May 19, 2017 6:20 PM

    Hi Awann,

    Did you have any load at the 12V output? What's the max output current? Was the current limit of you DC supply set too low? Would you provide the screenshot of the Vin, SW and Vout waveform if it's still not working?

    Thanks,

    Hong

  • Here is a picture of the current wired up part.The current limit is set to 1A, but it was drawing much less than that.Could it be because the part is not soldered to a pcb? It is connected to ground by wires.

  • Awann

    I think you really need to put this on a copper board with the correct layout. Flying wires like that, and not having a good GND plane is going to give you problems. I would not be surprised if you killed the IC. I would not recommend building the circuit like you did.

    Can you email me I have some questions for you. Aaron.hanson@analog.com