Need transistor number

[guitardad]

I have a unit with an open switching transistor

On the part it has N7P5, but nothing comes up in google

Unit is an ITVS-750. All in one audio unit. This switching transistor supplies main V to an LM7805

[nosaj]

Does it have any other numbers? I did a datasearch on the regulator but being unknown variables you will have some figuring to do.

Heres some samples as I could not find a schematic.
https://www.google.com/search?q=swit...0QsAQ#imgdii=_

Thanks,
Jason

[J M Fahey]

Replace it by function.

It probably helps the LM7805 by pre-lowering some too high rail voltage to a manageable level.

Might work switching, in which case there should be some coil or inductor very close to it, or linearly, in which case it might receive some raw voltage on the collector, have some voltage reference (usually a Zener) at the base and deliver anything from, say, +10 to +30V at its emitter, to the 7805 which does the final smoothing.

Pull it and measure voltage present at its solder pads to see what we are dealing with; also pinout and package.

Is it heatsinked?

Then we can reasonably guess a replacement.

[Jazz P Bass]

It may be a circuit to enhance the output current of the regulator.



A quick sketch of the units power supply would help.

[Mark Black]

A pic of the device in question might also help, if possible.

[guitardad]

A pic of the device in question might also help, if possible.

It's an SMD SOT23 style package.

The only numbers on the device are N7P5

Appears to me to act as a switch.

similar to this:
http://www.mouser.com/ProductDetail/...FYdzMgodWyIAqA

[Sock Puppet]

The 5 on the end could be a date code and scrolling to N7P here: The Solid-State Components Online Database - SMD-Code-Index - SMD Code Reference
shows a SOT-323 (very similar to the SOT-23) and a cross ref to Philips 2PB709ARW.

That's my best guess: 2PB709ARW :: NXP Semiconductors

The "P" means made in Hong Kong :-)

http://www.nxp.com/documents/data_sh...AXW_SERIES.pdf

[52 Bill]

Scan the board and see if there is another one that you can meter test. That may help in identifying what type of part it is.

[oc disorder]

A similar search to Sock Puppet but on "All Transistors" for N7P comes up with these

SMD Code Search

1 N7p 2PB709ARW SOT323 SMD Transistor
2 N7t 2PB709ARW SOT323 SMD Transistor
3 N7 2SC1654 SMD Transistor
4 N7 KN4L4Z SC75 SMD Transistor
5 N7 TMPT1654N7 TO-23 SMD Transistor
6 N72 TMPT3903 TO-23 SMD Transistor
7 N73 STC2073F SOT-89

and the first one is the same as sock puppets result.

EDIT: There is very little info on the device at "All transistors".

http://alltransistors.com/transistor...ansistor=50058

2PB709ARW Transistor Datasheet. Parameters and Characteristics.

Type Designator: 2PB709ARW

Material of transistor: Si

Polarity: PNP

Maximum collector power dissipation (Pc), W: 0.2

Maximum collector current |Ic max|, A: 0.1

and there are aprox. 250 equivalents based on the sparse data above !

[Sock Puppet]

All was going well until I came across this - also marked with an N7 code:

http://www.s-manuals.com/pdf/datashe...cds_vishay.pdf

[Jazz P Bass]

A very basic tracing out of what the transistor is hooked up to will go a long way in deciding which transistor to use.

I don't understand how the OP arrived at the conclusion that it is a 'switching transistor'.
Whatever that is.

NPN or PNP, voltage & current handling is how the transistor will be rated.

[guitardad]

A very basic tracing out of what the transistor is hooked up to will go a long way in deciding which transistor to use.

I don't understand how the OP arrived at the conclusion that it is a 'switching transistor'.
Whatever that is.

NPN or PNP, voltage & current handling is how the transistor will be rated.

Turned out to be just like a DTC114ECA (Digital Transistor). I tossed a DTC114 (non smd) in there and it worked. Sis was happy! Took it home!

I have no idea why the # on it was meaningless unless it was a proprietary mfg no.