Author Topic: inductor for boost converter  (Read 1440 times)

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Offline LaserTazerPhaserTopic starter

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inductor for boost converter
« on: August 29, 2019, 10:15:19 pm »
Are these any good for a fixed frequency 1.4Mhz boost converter?

https://lcsc.com/product-detail/Power-Inductors_Sunltech-Tech-SLP1265S101MTT_C254897.html

https://lcsc.com/product-detail/Power-Inductors_Shun-Xiang-Nuo-Elec-SMDRS1275-221M_C163690.html

The current handling is fine however the core material might have such high losses it might melt the solder as there is nothing depicted in datasheets pertinent to their operating frequencies. There are no graphs about inductance to frequency in datasheets.

« Last Edit: August 29, 2019, 11:07:02 pm by LaserTazerPhaser »
 

Offline LaserTazerPhaserTopic starter

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Re: inductor for boost converter
« Reply #1 on: August 29, 2019, 11:31:27 pm »
What specifically is needed to determine if the core material is capable of a particular switching frequency?
 

Offline LaserTazerPhaserTopic starter

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Re: inductor for boost converter
« Reply #2 on: August 30, 2019, 12:15:49 am »
What specifically is needed to determine if the core material is capable of a particular switching frequency?

I can't tell the material from its look, but the construction (cylindrical design with a blue color sealed top) looks suspiciously close to those 52kHz LM2576/150kHz LM2596 module inductors.

Also, why on earth do you need 100uH for a 1.4MHz boost converter? DCM is not essentially bad.

Going to determine if they will increase efficiency, considering the load current is very small.
 

Offline LaserTazerPhaserTopic starter

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Re: inductor for boost converter
« Reply #3 on: August 30, 2019, 12:28:57 am »
Going to determine if they will increase efficiency, considering the load current is very small.

If ripple is accepted, consider a smaller inductor and use pulse skipping mode.

A CCM boost converter is never ZVS, thus parasitic capacitance of a high inductance choke can contribute quite some loss.

There are certain values which will increase efficiency, and 100uH might be around that value. These appear fine for the high frequency operation.

https://lcsc.com/product-detail/Power-Inductors_Changjiang-Microelectronics-Tech-FXC1040-101M_C191165.html

https://lcsc.com/product-detail/Power-Inductors_Shun-Xiang-Nuo-Elec-SMMS1360-101M_C149534.html
 

Offline LaserTazerPhaserTopic starter

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Re: inductor for boost converter
« Reply #4 on: August 30, 2019, 12:38:34 am »
Will try other values by swaping them into the board. These appear fine for the high frequency operation.

They look good. Look like second sources of Vishay IHLx.

Do boost ICs become damaged from no load other than its voltage divider going into its feedback terminal?
 

Offline LaserTazerPhaserTopic starter

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Re: inductor for boost converter
« Reply #5 on: August 30, 2019, 12:59:11 am »
These are the same form factor - slightly smaller less expensive but no mention of frequency. https://lcsc.com/product-detail/New-Arrivals_COILMX-MS1040-101M_C380060.html

Whats this formfactor called? The nice blocks of ferrite.
 

Offline LaserTazerPhaserTopic starter

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Re: inductor for boost converter
« Reply #6 on: August 30, 2019, 01:28:49 am »
These are the same form factor - slightly smaller less expensive but no mention of frequency. https://lcsc.com/product-detail/New-Arrivals_COILMX-MS1040-101M_C380060.html

Whats this formfactor called? The nice blocks of ferrite.

Dunno. Without data from datasheet or curve plots, I can't tell.

I don't know that the package is called. I call them Vishay IHLx.

What are these inductors good for - which don't have data needed for determining frequency/currents from the manufacturer?

Some of those datasheets are entirely vacant of nearly everything but soldering temperature and dimensions.
 


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