TL431-Q1: Power Dissipation and Thermal Estimation

Dylan Zheng

Intellectual 1405 points

Part Number: TL431-Q1
Other Parts Discussed in Thread: TL431

Dear Expert,

The application as below. How to calculate the power dissipation of TL431 and estimate thermal?

Pdiss=Vcathode*Icathode? or Vref*Icathode?

Thanks,

Dylan

over 2 years ago

0 Trailokya Rai over 2 years ago

TI__Genius 10951 points

Hi Dylan

TL431 power will be calculated as follow -

Pdiss=Vcathode*Icathode

Regards

Trailokya

0 Dylan Zheng over 2 years ago in reply to Trailokya Rai

TI__Intellectual 1405 points

Hi Trailokya,

Could you please introduce the principle of why using Pdiss=Vcathode*Icathode?

Regards,

Dylan

0 Trailokya Rai over 2 years ago in reply to Dylan Zheng

TI__Genius 10951 points

Hi Dylan

The total power dissipation will be

P = VKA*IKA + VREF*IREF

Once TL431 is in regulation region, IREF will be less than 0.5% of IKA (Refer the electrical table) and VKA >= VREF. Hence we can neglect VREF*IREF component.

So please use VKA*IKA for your all the power dissipation calculation.

Regards

Trailokya

Power management

Power management forum

TL431-Q1: Power Dissipation and Thermal Estimation