This simple op amp circuit can be used to control the brightness of a LED. By placing the LED in the op amp feedback, it is driven in a constant- current mode. This eliminates the diode forward voltage temperature coefficient’s effect on its current and thus its brightness over temperature. This circuit is a voltage- controlled current source. (Circuit is created by Neil P. Albaugh, TI – Tucson)
Programmable-Brightness LED Control circuit:
Online Simulation of the Programmable-Brightness LED Control Circuit
The great feature of the TINA circuit simulator that you can analyze this circuit immediately with TINACloud the online version of TINA. Of course you can also run this circuit in the off-line version of TINA.
You can send this link to any TINACloud customers and they can immediatelly load it by a single click and then run using TINACloud.