THE FEUTEX TOOLKIT

Linear Regulator Thermal Budget

Estimate dissipation and junction temperature from a linear-regulator operating point.

Electronics workspace● Runs in your browser

01 Your input

InputVOutputVLoadAQuiescent currentAJunction-to-ambient resistanceK/WAmbient°C

02 Your result

View or copy raw result data

Result data

FormulaPd=(Vin−Vout)Iout+Vin Iq; Tj=Ta+θJA Pd

Sources and model references

https://www.ti.com/lit/an/slva462/slva462.pdf

Worked example

Inputs

Input: 12 V
Output: 5 V
Load: 0.1 A
Quiescent current: 0.001 A
Junction-to-ambient resistance: 50 K/W
Ambient: 25 °C

Expected results

Device loss: 0.712 W
Estimated junction temperature: 60.6 °C

Load the example in the workspace to reproduce these results. Display rounding does not change the underlying calculation.

How to use this tool

Enter the labeled inputs in the indicated units.
Calculate and compare every output against the stated model assumptions.

Try this example

{
  "vin": 12,
  "vout": 5,
  "i": 0.1,
  "iq": 0.001,
  "theta": 50,
  "ta": 25
}

Accuracy and scope

Steady-state estimate; thermal resistance is board-dependent; dropout and current limits excluded. Simplified analytical model; not a design recommendation or safety certification.

Is my data uploaded?

This tool runs locally in your browser. Input and output are not sent to a processing server. Copy or download your result before leaving the page.