The New Buck/Boost High Output Driver

[Hiemal]

Not to be a downer, but how is this any different than a flexdrive?...

 

[Blord]

The driver can deliver higher current than the flexdrive. The flexdrive max out at 1.5A and these drivers can handle 1.8A current.

 

[rhd]

It also means that you only need one of these to do what required 2 flexdrives.

I don't know if Foulmist has figured out pricing on these, but I'm sure it's going to be less than a flexdrive. Even if it was just the same price, you'd basically be saving 50%.

 

[foulmist]

The driver can deliver higher current than the flexdrive. The flexdrive max out at 1.5A and these drivers can handle 1.8A current.

it can handle 2A as well ...

I don't know if Foulmist has figured out pricing on these, but I'm sure it's going to be less than a flexdrive. Even if it was just the same price, you'd basically be saving 50%.

rhd, what's the flexdrv current pricing? boards will arrive next week so I can start soldering :san:

 

[rhd]

rhd, what's the flexdrv current pricing? boards will arrive next week so I can start soldering :san:

I'm the wrong person to ask about that, I never buy them.

But I think they're in the $25 to $30 range?

 

[Johnyz]

The LM3410 handles up to 2.8A, but it would need superior board design and a huge heatsink at that current.

 

[foulmist]

The LM3410 handles up to 2.8A, but it would need superior board design and a huge heatsink at that current.

Haha you are totally wrong there dude 2.8A is the switch current which in your logic would mean that the TPS63020 could handle 4A ...

switch current is not output current!


ok thanks rhd :beer:

 

[Johnyz]

Well, not entirely sure about this... There is no such thing as "max output current" in the datasheet, is there? I remember setting my first designs to around 1.4A and it was already giving me only 1.2A.

 

[foulmist]

Wait a minute......

Hmmmmmmm I might have misunderstood your post about the 2.8A now that I read it again.

Did you mean it can handle 2.8A switch current or output?

if you are not reffering to the output than my apologies! didn't understand you there pal :beer:

but the output can't reach 2.8A anyway not even the tps63020 can reach that in boost mode. although it might in buck

 

[Blord]

it can handle 2A as well ...

rhd, what's the flexdrv current pricing? boards will arrive next week so I can start soldering :san:

I was't saying 1.8A was the max. I am sure they go higher with good heatsinking. For practical use 1.8A is pretty much the upper limit of a 445nm diode.

I hope you can put the price down to $20 because the DIY boost driver cost only $10 and need only two to get the same currant output.

 

[foulmist]

I was't saying 1.8A was the max. I am sure they go higher with good heatsinking. For practical use 1.8A is pretty much the upper limit of a 445nm diode.

I hope you can put the price down to $20 because the DIY boost driver cost only $10 and need only two to get the same currant output.

I can't put the price to 20 cuz only the IC costs me like 11 bucks (VAT & shipping INCLUDED FOR MY COUNTRY >.<)

and the LM3410 which is in the free diy would cost me 5.6 bucks.

I am getting them from farnell cuz it's the only one in my country with reasonable shipping costs. If you can get them at much lower prices I can consider buying them from someone here. Any ideas?

Right now I'll be looking for $29 with leads attached and current sense resistors for your specific need. If I can get the IC's at lower price I will be able to lower down the final price.

 

[Johnyz]

About the current... forget it. How much does Farnell charge for shipping to your country? I guess I could build some for you, since they only charge 120 Czech Crowns to my house.

 

[rhd]

You know, you might want to consider having someone somewhere else make these, or at least buy the ICs and send them to you. For a QTY of 25, the TPS63020 from Mouser is only $5 each (plus like $8 shipping). That's half the price you're paying, and would probably bring your board cost down a whole bunch.

But to clarify for anyone else in this thread - a single board based on the TPS63020 running at an OUTPUT (boosted) current of 1.8A is likely to be much more efficient than two of our DIY Boost drivers paralleled.

All else being equal, you'd go for this boost driver before you'd go for two of the DIYs. Now, there's a price difference - maybe. We don't really know what the DIY boost will sell for when people start making them. If they sell for $15 each, then two of them is probably on par with the price of this TPS63020 driver. In which case, I'd go for the TPS63020 driver.

If you're a *real* DIYer though, you may look at the DIY Boost (The "Ben Boost") and like the idea of building one for ~$4. In which case it would be cool that you could get a 1.8A build up and running for about $8. That might be a pretty awesome route if you're really price conscious.

But to be clear - this is a more advanced board here - and it's a cool one.

 

[foulmist]

I am building the boards on my own.. I just need to find the IC's at better price... I will make some searching this weekend for a better price. If not I might ask someone to buy them for me and send them here, if it turns out cheaper.

EDIT: mouser would charge me $40 for shipping damn..

I could buy them from farnel for $6.8(without VAT) $8.16 (with VAT) but I have to take 100 pieces. otherwise I end up with the higher price... and I can't take 100 pieces right now. I will have to sell some first in order to make more cuz I don't have that kind of money.

stay tuned!

 

[rhd]

I am building the boards on my own.. I just need to find the IC's at better price... I will make some searching this weekend for a better price. If not I might ask someone to buy them for me and send them here, if it turns out cheaper.

EDIT: mouser would charge me $40 for shipping damn..

I could buy them from farnel for $6.8(without VAT) $8.16 (with VAT) but I have to take 100 pieces. otherwise I end up with the higher price... and I can't take 100 pieces right now. I will have to sell some first in order to make more cuz I don't have that kind of money.

stay tuned!

I'd offer to help, but a Canadian is probably not the best route to go.

Someone in the US could order 25x from Mouser for about $125 + $8 shipping. That's $133, plus the cost to ship to you, which is probably another $10. So say $145 for 25, which is $5.80 each, and the outlay upfront wouldn't have to be huge.

 

[tsteele93]

I'm the wrong person to ask about that, I never buy them.

But I think they're in the $25 to $30 range?

I've kind of gathered from your comments that you are not a fan of the flexdrive - why? I'm just curious. If it is none of my business, you can tell me that and I won't get my feelings hurt.

Or you can PM if it is private and you want to share, or just say it here if you like.