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ArcticMyst Security by Avery

17mm buck-boost driver (TPS63020 and LT6106)

Wolfman29

Wolfman29

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Definitely better than the Flex. Better than the IC you chose, too, methinks, Jared.

But still can't push the 2.2A 9mm 445s to their limits. None can. Except inefficient linears... and mine >:D
 





AnthoT

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Wolfman29 said:
Definitely better than the Flex. Better than the IC you chose, too, methinks, Jared.

But still can't push the 2.2A 9mm 445s to their limits. None can. Except inefficient linears... and mine >:D
Click to expand...

Very true :D


I'll actually look into boost ic's capable of 3 Amps ( I there are any) :D
 
Wolfman29

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I already have one in the works ;) You just wait till I get back from Chicago. BlitzBoost, anyone?
 
Wolfman29

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I know :p But always good to have driver tech beyond that which diodes can take ^_^
 
laserluke

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tsteele93 said:
How important do you think it is that you stay with the coilcraft inductor?

I know TI recommends it on the data sheet, but can we just use a 2uH or 1.2uH low DCR inductor. That really adds to the cost having to source the inductor from somewhere else and pay extra shipping on it rather than just add it to an order from digikey or somewhere else.

ALSO: What package is that considered to be? It is 4mmx4mm but I don't see anything like 0805 or 0603 or TO220 so that I could find something comparable to substitute.

ONE MORE THING: According to the coilcraft website, they don't appear to be in stock either - so these kind of suck.

Would any of these inductors work? And if not, what did I miss?


VISHAY DALE - IHLP1212BZER1R5M11 - INDUCTOR, 1.5UH, 5A, ±20% 3mm x 3.6mm x 2mm - PRICE: $0.72

TAIYO YUDEN - BRL3225T1R5M - INDUCTOR, 1.5UH, 2.2A, ±20% 3.2mm x 2.5mm x 1.7mm - PRICE: $0.132

VISHAY DALE - IHLM2525CZER1R5M01 - HIGH CURRENT INDUCTOR, 1.5UH 9A 20% PRICE: $1.84

VISHAY DALE - IHLP1212BZER1R5M11 - INDUCTOR, 1.5UH, 5A, ±20%PRICE: $1.16

VISHAY DALE - IHLP2525CZER1R5M01 - HIGH CURRENT INDUCTOR, 1.5UH 9A 20% PRICE: $1.31

VISHAY DALE - IHLM2525CZER1R5M01 - HIGH CURRENT INDUCTOR, 1.5UH 9A 20% PRICE: $0.92

MULTICOMP - MCBFS5220-1R5MU - INDUCTOR, 1.5UH, 6.7A, 20% PRICE: $0.38
Click to expand...

I have provided in the pcb a bigger landing pad to accept other inductors than coilcraft model. The coilcraft model is the reference inductor to obtain optimal conditions as suggested by TI but it's possible to simulate and mount another model. Here there are the landing pad dimensions:

attachment.php


XFL4020-152ME has the following characteristics:
DC resistance: max 0.0158 ohm
Saturation current at 20% inductance drop: 4.4A
RMS current for 40°C temperature rise: 9.1A
You can compare these key characteristic with other inductors to choose the right price-performance ratio.
For the inductor that you have listed:
- IHLP1212BZER1R5M11 - more DCR (0.032 ohm), lower saturation current (4.0A) and lower 40°C rise current (5A)... much more heat but probably usable
- BRL3225T1R5M - much more DCR (0.054 ohm) and very low saturation current (2.2A) and 40°C rise current (1.75A) - unusable
- IHLM2525CZER1R5M01 - very good (DCR 0.015 ohm, saturation 18A and 40°C current 9A) but too big (7x7mm)
- IHLP2525CZER1R5M01 - the same... (too big 7x7mm)
- MCBFS5220 - impossibly gigantic (12.95x9.5mm)

edit: you can use XFL4020-222ME (2.2uH) for the first tests (1142 in stock, probably you can order free samples)
 

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tsteele93

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OK, Luke - that really helps me see what I need to look for to find a reasonable substitute. I just don't see how the coilcraft is usable since it is only sold by coilcraft, expensive and out of stock.

I'm going to see what I can find.

EDIT: Can we use 2.2uH? How does that affect the circuit vs the 1.5uH or 1.2uH or 1uH?

Looking at the data sheet. It seems like 1uH should be ok as well, no?
 
Last edited:
AnthoT

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tsteele93 said:
OK, Luke - that really helps me see what I need to look for to find a reasonable substitute. I just don't see how the coilcraft is usable since it is only sold by coilcraft, expensive and out of stock.

I'm going to see what I can find.
Click to expand...

If anyone wants any of those coilcraft ones I got ~10 of the exact ones...
 
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