Thanks for the help keith!
I misunderstood it to be a BJT and refered to the same datasheet which you posted. I had plucked the component out and tested it with DMM it behaved as FET, then i noticed that the last letter of the SMD code is in lower case, 12p. This device is used in "power one" rectifier, model 13.48. In the driver circuit the PWM IC outputs are connected to the gates of these two FETs (12p and 1ss)......
The nearest I could find was Rohm DTA123 which is marked 12 but is a digital PNP. I don't know if the add the "p" as a date code. For 12p I can only find a 5 pin SOT-23 device.
Similarly for the 1ss - only 5 pin SOT23. There are devices with 1S but no 1s or 1ss in SOT23 that I can find.
They are always tricky. The codebooks don't contain everything, unfortunately.
Thanks again keith! the other SMD code is i suppose 1SS, i think i searched for it but could not find any FET in sot23 three pin , can you please guide me in this regard
The nearest I could find was Rohm DTA123 which is marked 12 but is a digital PNP. I don't know if the add the "p" as a date code. For 12p I can only find a 5 pin SOT-23 device.
Similarly for the 1ss - only 5 pin SOT23. There are devices with 1S but no 1s or 1ss in SOT23 that I can find.
They are always tricky. The codebooks don't contain everything, unfortunately.
If you can find out what the device needs to do then replacement probably isn't that difficult. Most SOT23 MOSFETs follow a standard pattern of connections.
The only transistors starting 1S in SOT23 I found were MMBT2369A, MSC3130 which are NPN and UNRF1AM, UNRF1AT which are Panasonic digital transistors. They aren't markedd 1SS though, as far as I can tell.
Thanks! Keith
i examined the devices under microscope and identified that the marking code which i thought to be 1ss was ss with inverted 'i' in place of 1. The device is BSS138. 12p still remains a mystery....
If you can find out what the device needs to do then replacement probably isn't that difficult. Most SOT23 MOSFETs follow a standard pattern of connections.
The only transistors starting 1S in SOT23 I found were MMBT2369A, MSC3130 which are NPN and UNRF1AM, UNRF1AT which are Panasonic digital transistors. They aren't markedd 1SS though, as far as I can tell.