DRV8243-Q1: stall current power dissipation

Sherry Liang

Part Number: DRV8243-Q1

Dear team,

We have H bridge power dissipation app note, but this doesn't include the power dissipation of stall current. How do we compute the power dissipation of stall current? the total power dissipation = working current dissipation+stall current dissipation, right?

	working current	stall current/duration time	frequency
first DRV8243-Q1	1A	2A/2s	10kHz
second DRV8243-Q1	0.5A	1.5A/2s	10kHz
third DRV8243-Q1	0.5A	1.5A/2s	10kHz

Thanks & Best Regards,

Sherry

over 2 years ago

0 Jacob Thompson over 2 years ago

TI__Mastermind 23421 points

Hey Sherry,

During stall current there is no additional working current, it would just be the stall current. so Total Power Dissipation during stall = Stall Current Dissipation.

In stall, the amount of heat generated is the power applied to the motor (voltage * current) since ALL this power is wasted since the mechanical power produced is zero (torque * ang. velocity = 0).

If you haven't already, you might want to check out the "Full Bridge Driver Junction Temperature Estimator (Rev. B)" calculation tool found in the tech docs: https://www.ti.com/product/DRV8243-Q1#tech-docs

Regards,

Jacob

0 Sherry Liang over 2 years ago in reply to Jacob Thompson

TI__Genius 10255 points

Hi Jacob,

Thanks for your help!

How to choose the input type when calculating the power dissipation? If the customer's duty cycle is 50%, which type should be selected?

according to H bridge power dissipation app note, I calculate the power dissipation is as attached excel. When the device use high side recirculation, the power dissipation is 0.34W. Then how do I enter User Input #9? When I enter as below, I don't see the junction temp change, why?

For stall current, Pstall=VM*I=13.5V*2A=27W, how do I consider the 2s duration? How do I calculate the temp rise? If the temp rise=27W*RθJA=837C?

DRV8243-Q1 power dissipation.xlsx Calculating Power Dissipation for a H-Bridge or Half bridge driver.pdf