TPS62420: Recommended inductor

Cody Watkins

Part Number: TPS62420
Other Parts Discussed in Thread: TMDSDOCK28335, TMDSCNCD28335, TMDXCNCD28388D, TMDSCNCD28379D, TMDSDOCK28379D, LAUNCHXL-F28379D

Hello!

We have been using TPS62420 for many years in a number of our reference designs, and its been working great! As part of this design we have been using 2 of the recommended inductors, VLF3010AT-2R2 and VLF3010AT-3R3.

These inductors have recently been marked as obsolete, looking at Digi-Key there wasn't a great pad-to-pad drop in. What are your recommendations? It is crucial that we find one which is able to be soldered into existing designs without modifications to their layouts.

Thanks,
Cody

over 5 years ago

0 Sabrina over 5 years ago

TI__Expert 8420 points

HI Cody,

You can use another inductor with similar properties in terms of: Inductance, current rating, DC resistance and operating temp range. For example you could use the proposed alternative on TDK website for VLF3010AT-2R2 and VLF3010AT-3R . The alternate inductor does not need to have the exact same landing pattern.

May I know on which reference designs these have been used so far?

Regards

Sabrina

0 Cody Watkins over 5 years ago in reply to Sabrina

TI__Mastermind 42195 points

Sabrina,

I would love to use the TDK alternate, however it seems that the landing pads are quite different.(I'm OK with them not being identical, however if feel these are too different. I have graphed it for one of the devices.

These are used in the following(not an exhaustive list):

TMDSDOCK28335
TMDSCNCD28335
TMDXCNCD28388D
TMDSCNCD28379D
TMDSDOCK28379D
LAUNCHXL-F28379D

Do we know of any pad-to-pad matches? I suspect many customers using these C2000 devices will begin to ask this question as these EVM are used as reference designs.

Regards,
Cody

0 Sabrina over 5 years ago in reply to Cody Watkins

TI__Expert 8420 points

Hi Cody,

got it now! Sorry I misunderstood your concern, I spent some time trying to find a similar inductor with the same landing pattern but seems to be difficult the closest I could get is this one, but the length is still bigger than what you currently have:

https://www.mouser.de/ProductDetail/Murata-Electronics/DFE322512F-2R2M=P2?qs=AQlKX63v8RugBXCoLvLHRA==

I will check other colleagues and inductor vendors if they have any recommendation and get back to you.

As this a holiday period almost everyone is out of Office this week, I will get back beginning of next week latest.

Regards

Sabrina

0 Cody Watkins over 5 years ago in reply to Sabrina

TI__Mastermind 42195 points

Great thanks Sabrina.

Regards,
Cody

0 Sabrina over 5 years ago in reply to Cody Watkins

TI__Expert 8420 points

Hi Cody,

Unfortunately I could not find an alternate inductor with the exact lad pattern. the solution a see would be to relayout the design with a other inductor land pattern

I am closing this thread now.

Regards

Sabrina

0 Cody Watkins over 5 years ago in reply to Sabrina

TI__Mastermind 42195 points

Sabrina,

I have identified components that will work with this footprint, can you confirm that these inductors will work with the TPS62420?

Wurth PN: 78438323033
Samida PN: CDRH2D18/HPNP-2R2NC

Regards,
Cody

0 Alfonso Furio over 5 years ago in reply to Cody Watkins

TI__Expert 3645 points

Hello,

I check and I can't find any other alternatives that fit the recommended landing pattern of the VLF3010AT family. On the producer website, the suggested alternative is: VLS3010CX-2R2M-1 (Interchangeability is not guaranteed).

I had a look at the two inductors that you post and in terms of specs they seem fine (the 3.3uH has a bit higher DCRmax). Are you sure that they fit in the landing pattern of the previous inductor?

0 Cody Watkins over 5 years ago in reply to Alfonso Furio

TI__Mastermind 42195 points

Do you see the increased DCRmax as an issue?

This part will not align perfectly to the pad. However, it does appear to have enough pad overlap and the soldermask will protect against an unintended shorting.

Regards,
Cody

0 Alfonso Furio over 5 years ago in reply to Cody Watkins

TI__Expert 3645 points

Hello,

due to the higher DCR you will have a bit more losses and efficiency will be consequently lower. In terms of functionality, no issue.

Power management

Power management forum

TPS62420: Recommended inductor