[WIP] 10mm DD-only LFPAK33 driver

35 posts / 0 new
Last post

Pages

wight
Offline
Last seen: 2 months 2 weeks ago
Joined: 11/27/2013 - 16:40
Posts: 4969
Location: Virginia, USA
[WIP] 10mm DD-only LFPAK33 driver

I thought that I’d already made one of these, but apparently I did not. Oops. I ran around in some PMs telling one or two folks to ‘go find it’… I felt bad about that so I went and made one this morning. Sad Wink

  • ~1mm physical keepout around the edges on top and bottom IIRC. Electrical & exposed copper keepout is a bit less.
  • B+ strap required as usual on this type of thing
  • Some vias under components, boo-hoo. The only thing that is truly sacred here is the gate pin on the LFPAK33, you really, really shouldn’t place a via under there – so I didn’t.
  • 0.7mm exposed copper on GND rings
  • 0805 sized passive components but using the small rounded pads.
  • LFPAK33 or similar MOSFET. See my other 15mm or less driver threads for any discussion on which MOSFET to use.

A10DD-33 v003

Still fine, still on a break. One day I’ll catch up with you folks! previous wight catchup Wink
list of my drivers & variants (A17DD, FET+1 stuff, WIP stuff, etc)

wight
Offline
Last seen: 2 months 2 weeks ago
Joined: 11/27/2013 - 16:40
Posts: 4969
Location: Virginia, USA

Reserved.

Still fine, still on a break. One day I’ll catch up with you folks! previous wight catchup Wink
list of my drivers & variants (A17DD, FET+1 stuff, WIP stuff, etc)

pilotdog68
pilotdog68's picture
Offline
Last seen: 6 months 2 weeks ago
Joined: 05/30/2013 - 23:31
Posts: 6420
Location: Held against my will in IOWA, USA

Hmm…. I have a BLFTINY10DD already assembled on my desk, but this looks much simpler to attach the strap to. I still haven’t figured out that bit….

My Favorite Modded Lights: X6R, S8 , X2R , M6, SP03

Major Projects:  Illuminated Tailcap, TripleDown/TripleStack Driver

wight
Offline
Last seen: 2 months 2 weeks ago
Joined: 11/27/2013 - 16:40
Posts: 4969
Location: Virginia, USA

It looks good to me right now, but I make no promises. Wink

v001 had a minor design rule violation (OSH Park would have successfully built it anyway)
v002 and v001 were missing GND ring vias
v003… who knows?

Silly

Still fine, still on a break. One day I’ll catch up with you folks! previous wight catchup Wink
list of my drivers & variants (A17DD, FET+1 stuff, WIP stuff, etc)

DB Custom
DB Custom's picture
Offline
Last seen: 3 days 7 hours ago
Joined: 01/13/2013 - 22:28
Posts: 20623
Location: Heart of Texas

I’ll find out as soon as they get em shipped. This tiny, they ought to fit in almost anywhere! lol

DB Custom
DB Custom's picture
Offline
Last seen: 3 days 7 hours ago
Joined: 01/13/2013 - 22:28
Posts: 20623
Location: Heart of Texas

I have seen 3.2A before, but the 10440 I just tested in direct drive with nothing but 2 wires and a cell showed 2.74A. So the cell will have to be a new one, and there’s just not much to be gained at 3A or so. The smaller FET can be used for space savings and it still does well. The Vishay Si2312CDS is a new SOT-23 format that might offer the most out of the package, either way though the cell is at the top of it’s game.

Gaining efficiency with the FET+1 layout is a critical gain, making that a no-brainer in a very tiny light that is capacity compromised.

Edit: Just tested another that charged up to 4.19V and delivered 3.16A directly wired to an XP-L V6 3D on a 20mm Noctigon. Ceiling is pretty much capped.

wight
Offline
Last seen: 2 months 2 weeks ago
Joined: 11/27/2013 - 16:40
Posts: 4969
Location: Virginia, USA

DBCstm, do you use a reverse polarity protection diode on that light?

Still fine, still on a break. One day I’ll catch up with you folks! previous wight catchup Wink
list of my drivers & variants (A17DD, FET+1 stuff, WIP stuff, etc)

DB Custom
DB Custom's picture
Offline
Last seen: 3 days 7 hours ago
Joined: 01/13/2013 - 22:28
Posts: 20623
Location: Heart of Texas

And yes, it’s there, as prescribed on all our drivers. And yes, it might gain a wee bit to bypass that, redundant though with a 3.2A draw on a 350mAh cell.

Might let me see 1000 lumens though… hmmmmmmm………

Rufusbduck
Rufusbduck's picture
Offline
Last seen: 1 year 2 months ago
Joined: 04/04/2012 - 15:34
Posts: 10389
Location: Golden state

D1 doesn’t drop voltage to the emitter but only to the mcu. Different current path. Battery+>LED+>LED->FET>Battery- . D1 is in the path that powers the gate.

Three Tanna leaves to give him life, nine to give him movement. But what if he eats the whole bag?

Scott

DB Custom
DB Custom's picture
Offline
Last seen: 3 days 7 hours ago
Joined: 01/13/2013 - 22:28
Posts: 20623
Location: Heart of Texas

If it’s not about the voltage, what then? It’s not really necessary to have in this light as I’M not gonna put the cell in backwards. And it’s around my neck 24/7/365. (virtually)

Rufusbduck
Rufusbduck's picture
Offline
Last seen: 1 year 2 months ago
Joined: 04/04/2012 - 15:34
Posts: 10389
Location: Golden state

Just saying that the diode drop doesn’t affect lumens. Any reduction in current draw to the mcu path(s) would help a tiny amount reducing sag but not sure if it would be measurable since it’s such a tiny fraction of another tiny fraction of DD draw.

Edit- what was I thinking? As Crux reminded me below while the diode isn’t in the led current path it certainly does affect the maximum voltage on the Gate which directly affects FET resistance.

Three Tanna leaves to give him life, nine to give him movement. But what if he eats the whole bag?

Scott

Rufusbduck
Rufusbduck's picture
Offline
Last seen: 1 year 2 months ago
Joined: 04/04/2012 - 15:34
Posts: 10389
Location: Golden state

Given that these cells are flat tops it’s a bit easier to mess up and drop one in backwards and this is about as “free” as anything gets.

Thanks Alex, it’s mind boggling how much time you have put into contributing to a worldwide shared resource.

This may not mean anything to anyone else but the main reason the components on the side opposite the attiny were crowded to the center was the narrow neck of a Mag Solitaire. I have plenty of the tiny10’s I can drop a 2502 on so that’s not an issue and this layout has a lot more room to work with along with a stronger B+ idea.

Three Tanna leaves to give him life, nine to give him movement. But what if he eats the whole bag?

Scott

Crux
Crux's picture
Offline
Last seen: 5 months 3 days ago
Joined: 05/03/2011 - 16:27
Posts: 227
Location: Northcoast, Ohio, USA

I've been thinking about the diode too. While it does not carry the LED current it does drop the voltage available to drive the FET, so depending on the FET and the battery voltage, the ON resistance may be higher than normal. (but maybe not enough to matter)

Aside from protecting the processor IC from reverse battery, it also isolates the power from the IC while programming it. (assuming the programmer supplies power to the chip)

What this means is without the diode the whole driver will be powered during programming, and because the PWM pin is one of the pins used during programming, the LED may follow the data on the that line. The blinking LED isn't necessarily a problem unless the power source can't handle the power draw and sags. This sag could corrupt the program process. This may all depend on the type of driver.

I'm not sure about this as I've not done any testing, but it seems reasonable to me.

Anyone have any insight on this?

H-Man
Offline
Last seen: 1 year 9 months ago
Joined: 09/27/2012 - 00:31
Posts: 95
Location: Ventura, CA

Part of me wants this for the giggle factor (3 amps off of a cell that is likely good for .250 AH means that all you can do is giggle during the 5 min runtime) part of me wants to figure out a way to get a linear regulator into the mix too.

I used that java circuit sim I did the SOS disable circuit in and it looks like that capacitor that is across the LED + pad and ground helps efficiency significantly at low duty cycles. With a 47 microF capacitor and 1% duty cycle, I’m getting a peak of ~160mA and a minimum of 20mA once I add some resistor to simulate real life circuit resistances. At .5% duty cycle, I’m getting a peak of 54mA and a min of 14mA.

I do horrible things to electronics in an effort to get them to do what I want.

Rufusbduck
Rufusbduck's picture
Offline
Last seen: 1 year 2 months ago
Joined: 04/04/2012 - 15:34
Posts: 10389
Location: Golden state

You’re right Crux, that part slipped my mind. It depends on how close to the elbow in the R vs Vg we’re operating since mV do count here. Not so much with purely 7135 based drivers. All the more reason to use the best FET.

Three Tanna leaves to give him life, nine to give him movement. But what if he eats the whole bag?

Scott

Rufusbduck
Rufusbduck's picture
Offline
Last seen: 1 year 2 months ago
Joined: 04/04/2012 - 15:34
Posts: 10389
Location: Golden state

Dale go ahead and try it with a jumper instead of the diode. As Crux points out it could very well change the resistance of the FET enough to result in higher amps.

Three Tanna leaves to give him life, nine to give him movement. But what if he eats the whole bag?

Scott

DB Custom
DB Custom's picture
Offline
Last seen: 3 days 7 hours ago
Joined: 01/13/2013 - 22:28
Posts: 20623
Location: Heart of Texas

Can’t get any higher than a direct connection to a cell, and that nets 3.16A, which is about where I’m at in the light. So the little Efest IMR10440 has hit the ceiling. Is there a fet out there that’s gonna boost the cell?

DB Custom
DB Custom's picture
Offline
Last seen: 3 days 7 hours ago
Joined: 01/13/2013 - 22:28
Posts: 20623
Location: Heart of Texas

Think I’m just gonna stick a Luminus SBT-70 in it and run it as a mule. Silly

H-Man
Offline
Last seen: 1 year 9 months ago
Joined: 09/27/2012 - 00:31
Posts: 95
Location: Ventura, CA

I’m going to mention this now so you have someone to blame if it ever comes into existence: XPH70 penlight. 2xIMR10400 and a reflector slightly taller than the LED.

I do horrible things to electronics in an effort to get them to do what I want.

wight
Offline
Last seen: 2 months 2 weeks ago
Joined: 11/27/2013 - 16:40
Posts: 4969
Location: Virginia, USA

H-Man wrote:
[snip]part of me wants to figure out a way to get a linear regulator into the mix too.[snip]
I also released one of those today: 10mm DD+single-7135 driver: double sided 10440 torture for Dual-PWM

Still fine, still on a break. One day I’ll catch up with you folks! previous wight catchup Wink
list of my drivers & variants (A17DD, FET+1 stuff, WIP stuff, etc)

Rufusbduck
Rufusbduck's picture
Offline
Last seen: 1 year 2 months ago
Joined: 04/04/2012 - 15:34
Posts: 10389
Location: Golden state

XPH 50 on 10mm XM sink pad might actually fit in a 2 × 10440 host. AKA AAA Minimag.

Edit- or you could try it with 2 × 10180 in a solitaire.

Three Tanna leaves to give him life, nine to give him movement. But what if he eats the whole bag?

Scott

H-Man
Offline
Last seen: 1 year 9 months ago
Joined: 09/27/2012 - 00:31
Posts: 95
Location: Ventura, CA

Rufusbduck wrote:
XPH 50 on 10mm XM sink pad might actually fit in a 2 × 10440 host. AKA AAA Minimag.

Edit- or you could try it with 2 × 10180 in a solitaire.


A XPH70 should fit too. It fits on a 9.9mm diameter circle. Do they make IMR 10180 cells? The smallest IMR cells I can find are 10400.

I do horrible things to electronics in an effort to get them to do what I want.

Rufusbduck
Rufusbduck's picture
Offline
Last seen: 1 year 2 months ago
Joined: 04/04/2012 - 15:34
Posts: 10389
Location: Golden state

The veleno 10180 at bang good is lithium cobalt. Any reason it has to be IMR? Other than don’t over discharge.

Three Tanna leaves to give him life, nine to give him movement. But what if he eats the whole bag?

Scott

Rufusbduck
Rufusbduck's picture
Offline
Last seen: 1 year 2 months ago
Joined: 04/04/2012 - 15:34
Posts: 10389
Location: Golden state

At a only a few hundred mA 2 × 10180 probably won’t be as bright as and XML with a 10440 though.

Three Tanna leaves to give him life, nine to give him movement. But what if he eats the whole bag?

Scott

H-Man
Offline
Last seen: 1 year 9 months ago
Joined: 09/27/2012 - 00:31
Posts: 95
Location: Ventura, CA

Rufusbduck wrote:
The veleno 10180 at bang good is lithium cobalt. Any reason it has to be IMR? Other than don’t over discharge.

I don’t think ICR can cope with the heavy drain (that the XHP50 and XHP70 would demand to justify putting it in a light instead of an XM-L2/XP-L2) that well.

If I’m putting an emitter that expensive into a light, I’m going to drive it hard enough to justify the cost.

I do horrible things to electronics in an effort to get them to do what I want.

wight
Offline
Last seen: 2 months 2 weeks ago
Joined: 11/27/2013 - 16:40
Posts: 4969
Location: Virginia, USA

H-Man wrote:
Rufusbduck wrote:
The veleno 10180 at bang good is lithium cobalt. Any reason it has to be IMR? Other than don’t over discharge.

I don’t think ICR can cope with the heavy drain (that the XHP50 and XHP70 would demand to justify putting it in a light instead of an XM-L2/XP-L2) that well. If I’m putting an emitter that expensive into a light, I’m going to drive it hard enough to justify the cost.
Think harder about what RBD is trying to tell you. Sad

Still fine, still on a break. One day I’ll catch up with you folks! previous wight catchup Wink
list of my drivers & variants (A17DD, FET+1 stuff, WIP stuff, etc)

Rufusbduck
Rufusbduck's picture
Offline
Last seen: 1 year 2 months ago
Joined: 04/04/2012 - 15:34
Posts: 10389
Location: Golden state

Besides, we still have to describe the Zener mod for this chihuahua for any of that to happen.

Three Tanna leaves to give him life, nine to give him movement. But what if he eats the whole bag?

Scott

wight
Offline
Last seen: 2 months 2 weeks ago
Joined: 11/27/2013 - 16:40
Posts: 4969
Location: Virginia, USA

Rufusbduck wrote:
Besides, we still have to describe the Zener mod for this chihuahua for any of that to happen.

Due to the small size of this driver, an SOD-323 Zener diode is best.
  • Simply install the load resistor in place of D1, then place the Zener diode horizontally between the bottom of that and the bottom of C1.
  • Due to the small size of the Zener diode it can also be installed entirely below the D1 position (eg next to the FET).

In either case the cathode of the Zener diode will face the ‘D1’ identifier (PCB marking) and the anode of the Zener diode will face the outside of the PCB.

Still fine, still on a break. One day I’ll catch up with you folks! previous wight catchup Wink
list of my drivers & variants (A17DD, FET+1 stuff, WIP stuff, etc)

Rufusbduck
Rufusbduck's picture
Offline
Last seen: 1 year 2 months ago
Joined: 04/04/2012 - 15:34
Posts: 10389
Location: Golden state

Scrape back a bit of solder mask between “1” of D1 & “C” of C1 ?

Three Tanna leaves to give him life, nine to give him movement. But what if he eats the whole bag?

Scott

wight
Offline
Last seen: 2 months 2 weeks ago
Joined: 11/27/2013 - 16:40
Posts: 4969
Location: Virginia, USA

Rufusbduck wrote:
Scrape back a bit of solder mask between “1” of D1 & “C” of C1 ?
I think that the Zener diode may be turned onto it’s side and used in the “hug” position.

Still fine, still on a break. One day I’ll catch up with you folks! previous wight catchup Wink
list of my drivers & variants (A17DD, FET+1 stuff, WIP stuff, etc)

H-Man
Offline
Last seen: 1 year 9 months ago
Joined: 09/27/2012 - 00:31
Posts: 95
Location: Ventura, CA

wight wrote:
H-Man wrote:
Rufusbduck wrote:
The veleno 10180 at bang good is lithium cobalt. Any reason it has to be IMR? Other than don’t over discharge.

I don’t think ICR can cope with the heavy drain (that the XHP50 and XHP70 would demand to justify putting it in a light instead of an XM-L2/XP-L2) that well. If I’m putting an emitter that expensive into a light, I’m going to drive it hard enough to justify the cost.
Think harder about what RBD is trying to tell you. Sad

The grammar makes the statement hard to decode. It almost sounds like he is saying that an XHP70 being ran off of 2S IMR10400 is too much or that he won’t even consider the 2xAAA formfactor, the first is absurd the second is personal preference.

I consider risk of running unprotected cells down an acceptable risk if it means I’m able to build a flashlight that is a satire of the FL1 standard (by having the light start out at around 3A and then after the initial measurement, it takes it down to 11% output so that it can run for almost an hour at ‘2000’ lumens).
Cell reversal is unlikely IMO. What is the minimum Vf of the XPH70? I know an XML has a minimum Vf of around 2.2v and at that voltage, current draw is pretty much nonexistant. Min vf for any significant current flow was 2.3v so a 2S2S die config for the XHP70 shouldn’t be able to reverse cells. It may kill the cells if you leave it on for hours though. Does this driver have voltage monitoring?

I do horrible things to electronics in an effort to get them to do what I want.

Pages