LED Power supply

What is the meaning of Ta, Tc on LED driver

Electronic products, such as switching power supplies, drivers labeled with Ta, Tc represents what means

Ta ambient temperature: Temperature Ambient

Tc surface temperature of the object: Surface Temperature of the body refers to the surface temperature of the device.

There are also the following explanations.

Ta: Actual ambient temperature Actual ambient temperature

Tc: Surface Temperature of the body

It is a special symbol to indicate

Measurement of Ta and Tc

The ambient temperature level is challenging to determine. The dimension of the Tc temperature is less complicated and also more reputable. As part of the design process, Xinreal’s carries out sizes for both Ta and Tc and makes sure that both measurements meet the highest requirements. And also, the Tc has received a datasheet listed below picture. This allows the luminaire maker to establish the anticipated lifetime of the control gear based upon the Tc temperature, which is much easier to gauge.


Position of the Tc point

LED bulb lamp above the logo TC:75 ℃ / TA:50 ℃ is what means 

TA is the ambient temperature, TC is the temperature of the bulb lamp shell, sometimes also marked a TJ <= 110 ℃ / this is the junction temperature of the LED chip.

LED energy-saving lamps marked above the Ta and Tc temperature are not representative of the ambient temperature and operating temperature

Ta refers to the maximum allowable temperature of the internal coil.

Tc refers to the maximum permissible housing temperature.

These data are generally used in the design phase of lamp development.

What temperature do the temperature TA and TC in the transistor specification represent, respectively?

I. TA temperature represents ambient temperature. Ambient temperature is a physical quantity that indicates the degree of a hot and cold environment.

Second, the TC temperature represents the critical temperature. The maximum temperature at which a substance changes from a solid state to a liquid form is called the required temperature. Each substance has a specific temperature above which gaseous substances will not liquefy no matter how much the pressure is increased, and this temperature is the critical temperature.

Extended information.

Every substance has a specific temperature above which a gaseous substance will not liquefy, no matter how much the pressure is increased. This temperature is the TC temperature (critical temperature). Therefore, to melt a substance, we must first try to reach its critical temperature. Some substances, such as ammonia and carbon dioxide, have a critical temperature higher than or close to room temperature, and they can be easily compressed into liquid at room temperature.

Some substances, such as oxygen, nitrogen, hydrogen, and helium, have a shallow critical temperature, with helium having a critical temperature of -268°C. To liquefy these gases, specific cryogenic techniques must reach their respective critical temperatures and then melt them by increasing the pressure.

Usually, the gaseous substances above the critical temperature are called gases, and the gaseous substances below the critical temperature are called vapors. The critical temperature is the temperature at which a sense is in a crucial state, called the “critical temperature. Cooling and pressurization are the conditions for liquefying a gas. However, it is not necessarily possible to liquefy a gas by only pressurizing it, and it depends on whether the gas is below the critical temperature at that time.

If the gas temperature exceeds the critical temperature, no matter how to increase the pressure, the gaseous material will not liquefy. For example, the critical temperature of water vapor is 374℃, which is much higher than the average temperature; therefore, typically, water vapor is very easy to cool into water.

What is the meaning of “TA=25℃ and TC=25℃” in the chip data? 

For example

PD @TA = 25°C Power Dissipation 3.8 W

PD @TC = 25°C Power Dissipation 180 W

Ta: Actual ambient temperature Actual ambient temperature

Tc: Surface Temperature of the body The surface temperature of the object

Simply put, your product can only go up to 3.8W at room temperature (25°C),

But if you give good heat dissipation conditions to ensure the product is 25℃, it can only carry 180W

LED driver on Ta, Tc each indicate what temperature

Ta is the best working temperature limit value of the power supply, Tc table marks the highest temperature of the entire drive. For example, the label Ta = 50 degrees, meaning that work within the 50-degree environment, life is the highest, every more than 10 degrees, life is reduced by two. The Tc point mainly measures the temperature, the temperature probe to be attached to the Tc point.




您的电子邮箱地址不会被公开。 必填项已用*标注

12 − 9 =

More than 400+ different power supply variable.

5V power supply is widely used in LED display and some other conditions.

24V Applicance Soluction




400w power supply is a great choice for use in lights. It can provide enough power for all of your needs, and it is also very reliable.

Waterproof power supplies are available in a variety of sizes and styles, so you can choose one that best suits your needs.

New Product

Social Media

New Post

Get The Latest Updates

Subscribe To Our Weekly Newsletter

No spam, notifications only about new products, updates.


en English

The Newest & Hottest Products In 2022

All your answers are in SANPU’s monthly report, 2022

We picked up the most popular items from 1,000+ items of our clients, to help you find the wining product.

Ask For A Quick Quote

We will contact you within 1 working day, please pay attention to the email with the suffix “@smpspower.com”.