# Led-driver (BJT)

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To set up the LED driver. The requirements are:

The current through the LED should be 20mA ± 1mA

The IC/IB should be around 25

I find: RB=43000 ohm, and Rc=180ohm , that meet the requirements, so, the LED driver works properly.

I have a couple questions if someone can give some help!

_Which area it uses and which area can be used to vary the brightness if needed.

_ What are the values VCE, VBE

_What kind of amplifier this is and how the transistor β affects RB. (VOLUNTARY)

• Your questions sound too much like homework questions to me. Are they? – Bimpelrekkie May 25 '20 at 11:00
• @Maikel - Hi (a) You say "BJT" in the title, but your first schematic shows a MOSFET. Please clarify/fix. (b) Your question includes the word "area" (twice), in a context which doesn't make sense. I'm quite sure that you mean something else. Please clarify/fix. – SamGibson May 25 '20 at 19:24

• No, $V_{BE}$ and $V_{CE}$ are not BJT parameters found in the datasheet. Select Rb based on minimum RB...what does that mean? – Elliot Alderson May 25 '20 at 13:24