LM5145: LM5145 heating up

vivek raja

Part Number: LM5145
Other Parts Discussed in Thread: LM5146

Tool/software:

Hi,

Anybody suggests the IC LM5145, Buck Regulator Positive Output Step-Down DC-DC Controller, the reason of heating. The layout side we found through thermal pad via only gnd is connected ground plane. There is no external copper which can help in reduce heating. Is the layout cause any issue or please suggest. FYI, LM5145 Component placed in Bottom. Total 4 layers @ 1.6mm thick Top, ground, power, Bottom

Regards

Vivek

Mob:9632322773

2 months ago

0 Timothy Hegarty 1 month ago

TI__Guru* 75882 points

Hi Vivek,

I recommend copying the LM5145 and LM5146 EVM designs as much as possible. To reduce IC dissipation, consider using an external VCC (8V to 13V). For example, if Vout = 12V, connect VOUT to VCC through a diode. This reduces the bias current consumption from VIN. Secondly, use FETs with low Qg, as the DC gate drive current from VCC to drive each FET is Qg*Fsw.

Regards,

Tim

0 vivek raja 1 month ago in reply to Timothy Hegarty

Prodigy 20 points

Hi Tim,

Great and Thanks for the response and this is resolved my issue.

Regards

Vivek

0 Timothy Hegarty 1 month ago in reply to vivek raja

TI__Guru* 75882 points

Thank you, Vivek.

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LM5145: LM5145 heating up