Yahoo Answers is shutting down on May 4th, 2021 (Eastern Time) and beginning April 20th, 2021 (Eastern Time) the Yahoo Answers website will be in read-only mode. There will be no changes to other Yahoo properties or services, or your Yahoo account. You can find more information about the Yahoo Answers shutdown and how to download your data on this help page.

Trending News

Promoted
Ak2ng
Ak2ng asked in Science & MathematicsEngineering · 1 decade ago

Which is ideal as a Current Mirror? BJT or MOSFET?

Hi All, Im trying to build a current mirror out of a transistor but wasn't sure which route to go. Characteristics which are important are:

1) Power

2) Current range. The transistor will be powered off a 5V rail. I want to be able to have the widest range in current by varying the biasing resistor. ie: for Mosfet, this is limited by its threshold voltage.

3) Package size

Thanks!

2 Answers

Relevance
  • billrussell42
    Lv 7
    1 decade ago
    Favorite Answer

    BJT current mirrors are usually implemented in ICs as the two transistors have to be matched.

    And if you start dissipating any power in the transistors, you will lose that match.

    If you just want a constant current sink with discrete transistors, there are better methods, such as a common base transistor, or using opamps.

    .

    Source(s): http://en.wikipedia.org/wiki/Current_mirror
  • buncie
    Lv 4
    4 years ago

    Bjt Current Mirror

    Source(s): https://shrinke.im/a9Kic
Still have questions? Get your answers by asking now.