HT1308 chip on simple cellphone SMPS

Discussion in 'General Electronics Chat' started by Willen, Jan 6, 2016.

  1. Willen

    Thread Starter Member

    Nov 13, 2015
    I found a cellphone SMPS and it has 8 pin DIP HT1308 chip. Now the SMPS failed and I am staring on the device. I tested all parts and seems fine. I am doubt on the chip. The chip seems that it's a 13008 NPN transistor but I am not sure. Please see the schematic and tell me.

    I downloaded the datasheet of HT1308 DIP chip but it was written in Chinese. I have attached a schematic too.
  2. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
    Whats your question?
    Its a PFM converter chip..
  3. Willen

    Thread Starter Member

    Nov 13, 2015
    I guessed it's just a BJT 13008 transistor. So I am asking for conform! Can you tell me more about 'PFM'.

    If the chip is not a NPN then I am wishing to use a 13008 NPN instead of the IC, maybe with little modification .
    Last edited: Jan 6, 2016
  4. AnalogKid

    Distinguished Member

    Aug 1, 2013
    The chip is a complete switching power supply controller including the output power transistor, not a simple NPN. In this circuit it cannot be replaced by an NPN transistor of any kind.