# Understanding Thermal Characteristics for Microchip CL2N3-G Constant Current LED Driver

I'm having trouble interpreting the thermal characteristics of the Microchip CL2N3-G Constant Current LED Driver chip.
Here's the datasheet: CL2N3-G Constant Current LED Driver 1

What I want to do is to power a single LED from a 60 VDC power source.
I'm planning on using the TO-92 package.

The problem I'm encountering is when I calculate the temperature rise of the CL2N3-G.
The spec states for the TO-92 package a thermal resistance of 132°C/W.
Here's the equations I'm using:

    60 V - 2.1 V (LED Vf) * 20 mA = 1.152 W
1.152 W * 132 (Thermal Resistance) = 158.8°C


This seems like a ridiculously high temperature just to power a single LED. Is this correct or am I missing something?

Thanks for your assistance and insights.

• There are simpler ways of powering a LED from 60V. Is this LED just an indicator for something? Do you really need a 20 mA LED? – mguima Sep 14 '20 at 6:20
• I agree there are many other LED options. But the LED choice was not mine. I'm just working with the hand that was dealt to me. – DrJackK Sep 15 '20 at 15:15