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I was looking at this Texas Instruments datasheet and saw this scheme:

enter image description here

Could anybody tell me what kind of transistors are on the left side of the diagram? I have never seen that symbol before, nor can I find any information on it.

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  • \$\begingroup\$ You can see also one ordinary transistor with no Schottky symbol. It's used as emitter follower which is not saturation prone way to use transistors. The others have the Schottky diode to sink the excessive base current via the Schottky diode as already presented. Saturated transistor has a big delay to turn to OFF state from ON state and the Schottky diode prevents the saturation due it's low voltage drop. The idea works also with discrete switching transistors. \$\endgroup\$
    – user136077
    Commented Mar 23, 2020 at 11:33
  • \$\begingroup\$ That data sheet you linked to seems to be a shrunk down version of the original one. Other data sheets for "ls04" have in their title "low power schottky". If you had used this in your GOOGLE search, you would found a plethora of information on Schotty and Low Power Schotty technology. \$\endgroup\$
    – SteveSh
    Commented Mar 23, 2020 at 11:50
  • \$\begingroup\$ @SteveSh good to know. I have just started studying this field at uni so almost zero experience. What you guys are saying here feels like real enlightenment :) \$\endgroup\$
    – Victor
    Commented Mar 23, 2020 at 12:12
  • 1
    \$\begingroup\$ TI's ALS application note has more than you ever wanted to know. \$\endgroup\$
    – CL.
    Commented Mar 23, 2020 at 13:06

1 Answer 1

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The circuit utilizes Schottky transistors as opposed to normal BJTs. Note that the title of the diagram is "LS04" where LS = low-power-schottky. From the wiki page quoted, a Schottky transistor is like this: -

enter image description here

Effective internal circuit composed of Schottky diode and bipolar junction transistor.

Another quote: -

A Schottky transistor is a combination of a transistor and a Schottky diode that prevents the transistor from saturating by diverting the excessive input current. It is also called a Schottky-clamped transistor.

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  • \$\begingroup\$ Thank you so much! Don't know how this hasn't popped out on Google search \$\endgroup\$
    – Victor
    Commented Mar 23, 2020 at 11:12
  • \$\begingroup\$ @Victor - What search terms did you use for your GOOGLE search? \$\endgroup\$
    – SteveSh
    Commented Mar 23, 2020 at 11:42
  • \$\begingroup\$ Not anything that could've lead me to the result, apparently. I searched for types of transistors in general, but couldn't find this one \$\endgroup\$
    – Victor
    Commented Mar 23, 2020 at 12:11

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