LDO Loss and Temperature Rise Calculator

🔌 LDO Loss & Thermal Rise Calculator

Input Voltage (V):

Output Voltage (V):

Load Current (A):

LDO Package:

PCB Layers:

Copper Thickness (oz):

Vias Top to Bottom:

RθJC (°C/W):

Environment:

⚙️ Overview:

This LDO Loss & Temperature Rise Calculator is a powerful engineering tool designed to help you estimate:

Power dissipation in a linear voltage regulator (LDO)
Temperature rise on the PCB based on real layout data
Junction temperature using both datasheet and PCB-level thermal models

It considers electrical input, package footprint, PCB design (pad size, layers, copper thickness), and airflow conditions using IPC-2152 thermal resistance principles. This calculator ensures safe thermal design for any application using an LDO.

🧮 Key Equations Used:

🔋 Power Dissipation in LDO:

The LDO drops excess voltage across itself and converts it directly into heat. Power loss is calculated as: P_loss=(V_in−V_out)×I_load

Where:

V_in is the input voltage
V_out is the regulated output voltage
I_load is the current drawn by the load

🌡️ Temperature Rise Estimation:

The temperature rise of the device above ambient is given by: ΔT=P_loss×R_θJA

Where:

R_θJA is the junction-to-ambient thermal resistance in °C/W
This is calculated or estimated using IPC-2152 guidelines based on copper area, pad size, number of layers, and airflow

🧠 Junction Temperature:

Once the temperature rise is known, the final junction temperature is estimated as: T_junction=T_ambient+ΔT