4
\$\begingroup\$

http://www.mouser.com/ds/2/395/DTA124%20EE%20A12-248319.pdf

It says it is a PNP transistor but symbol is of NPN transistor. The equivalent circuit shows the transistor sitting between load and ground which is how NPN is typically used.

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  • 3
    \$\begingroup\$ looks messed up to me... \$\endgroup\$
    – Trevor_G
    Oct 29 '17 at 9:25
  • \$\begingroup\$ DTA124 is a PNP device. eu.mouser.com/Search/Refine.aspx?Keyword=DTA124 \$\endgroup\$
    – G36
    Oct 29 '17 at 9:25
  • 5
    \$\begingroup\$ Don't buy that. \$\endgroup\$
    – Oskar Skog
    Oct 29 '17 at 9:28
  • 1
    \$\begingroup\$ It is also described as a diode! \$\endgroup\$ Oct 29 '17 at 9:41
  • 1
    \$\begingroup\$ Someone no speaky da gud English me thinks, but with a Japanese accent. \$\endgroup\$
    – Trevor_G
    Oct 29 '17 at 15:17
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The DTA124 is a PNP transistor originally made by Rohm, and Rohm's datasheet is consistent.

Taiwan Semiconductor intends its DTA124 to be clone of that, so it must be a PNP, too. There are lots of similar DTA/DTC datasheets for all the resistor combinations, so it is somewhat understandable (but not excusable) that these copy/paste errors can slip through QC (especially if you have to cut costs to be profitable at cloning).


As for the ground: Taiwan Semiconductor copied some NPN circuit image, and left out the complete explanation of the PNP signals:

DTA124 internal circuit

Here, the ground is the most positive part of the circuit. And since the emitter is the fixed voltage against which the other voltage levels are measured, it is technically correct to call it "ground".

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2
  • \$\begingroup\$ The Taiwan Semi datasheet didn't copy this diagram correctly. The Taiwan Semi datasheet shows the emitter arrow pointing away from the base. \$\endgroup\$
    – The Photon
    Oct 29 '17 at 16:23
  • \$\begingroup\$ Sorry; I was focused on the ground issue. \$\endgroup\$
    – CL.
    Oct 29 '17 at 16:39
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\$\begingroup\$

Something in the datasheet is wrong. The question is what.

I'm inclined to think it's most likely the symbol, and the device is actually a PNP type. The reason is that the Vcc, "input" and "output" voltages are specified with negative values.

But it would be wise to get a sample and do some checking with a multimeter before committing to the part. I also don't see any drawing showing which physical pin is which, so that's another thing to check.

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  • 5
    \$\begingroup\$ POP type, lol. I used to have a lot of trouble with those! \$\endgroup\$ Oct 29 '17 at 10:36
  • 4
    \$\begingroup\$ Don't they all go POP if you don't use them right? \$\endgroup\$
    – Trevor_G
    Oct 29 '17 at 13:44
  • 4
    \$\begingroup\$ Autocorrect knows the truth once again. \$\endgroup\$
    – The Photon
    Oct 29 '17 at 14:49

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