LM338: LM338K

kiko

Part Number: LM338

Hello,

We have 3 LM338K chained in parallel that power motor of the door (adjustable vitesse door), the peak lead curent to move the door is more than 15A;

The problem is after x time the LM338K break down. we suspect that the 3 LM338K is not enough, can you please tell me if you have an equivalent that provide more than 5A in output?

and can you explain the reason why the LM338K break down and what is the life time of this components?

Thanks in advance for your reply,

kiko

over 8 years ago

0 David Hopkins over 8 years ago

TI__Expert 8905 points

Hi Kiko,

An LDO controller with an external FET may be a better solution, or more parallel LM338s.

www.ti.com/.../ldo-controller-external-fet-products.page

The breakdown could be due to the current density and heat level, or it could be due to inductive kickback from the motor causing voltages outside of abs max on the LM338's. Can you provide scope captures of Vin and Vout, especially when the current is rapidly changing?

Thanks!
David

0 kiko over 8 years ago in reply to David Hopkins

Prodigy 40 points

Hi David,

Thanks for the expalanationI want to send you the schematic of the circuit and the scope capture but in this forum i don't know how?

Can you give an email adress where i can send you the scope catures?

Best regards,

Kiko

0 David Hopkins over 8 years ago in reply to kiko

TI__Expert 8905 points

Hi Kiko,

Best way for the scope captures is to just attached the pictures to the forum posting.

See here for more info:

e2e.ti.com/.../149.4-3-inserting-an-image-on-e2e

Power management

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LM338: LM338K