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Hi folks,

I'm trying to model an infrared remote control transmitter circuit that I'm designing and haven't had much luck finding a SPICE model for the higher-power IR LEDs like I'm using.

In this case, I have the OSRAM SFH4248 940nM emitter, and their site doesn't have any models for their IR LEDs.



I've also looked in the files area here without any luck.

Could anyone point me to a model for this diode?

Thanks!

--- In LTspice@..., "nedkonz" <ned@...> wrote:

Hi folks,

I'm trying to model an infrared remote control transmitter circuit that I'm designing and haven't had much luck finding a SPICE model for the higher-power IR LEDs like I'm using.

In this case, I have the OSRAM SFH4248 940nM emitter, and their site doesn't have any models for their IR LEDs.



I've also looked in the files area here without any luck.

Could anyone point me to a model for this diode?

Thanks!

Hello,

The model for the OSRAM SFH4248 is in the file
OSRAM-IR-POWERTOPLED.lib




.MODEL SFH4248 D
+ IS= 1.50099E-15
+ N= 1.570213683
+ RS= 0.762136823
+ IKF= 392.8188163
+ IBV = 0.00000001
+ NBV = 1
+ IBVL = 0.000000001
+ NBVL = 180
+ BV = 24
+ CJO = 1.46E-11
+ VJ = 0.56
+ M = 0.055
+ FC = 0.4
+ TT = 0.000000008
+ EG = 1.3


Best regards,
Helmut

In message <kkf3is+3juc@...>, dated Sun, 14 Apr 2013, Helmut <helmutsennewald@...> writes:

N= 1.570213683
+ RS= 0.762136823
+ IKF= 392.8188163

Not Helmut's responsibility, but isn't it disquieting that these are given to 10 significant figures? Doesn't inspire confidence. Can we sue if IKF turns out to be 392.8188162?(;-)
--
OOO - Own Opinions Only. See www.jmwa.demon.co.uk
Things to do today: Cut a hole in reality and push a turnip through.
John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK

Hello John,

Most models from other vendors don't have Ikf at all.
So the models from OSRAM are at least as good as the models
from other vendors. I recommend to use the OSRAM models.

Best regards,
Helmut

--- In LTspice@..., "Helmut" <helmutsennewald@...> wrote:

The model for the OSRAM SFH4248 is in the file
OSRAM-IR-POWERTOPLED.lib

Thanks!

I saw their SPICE models but not that one. And the "Simulation Models" link from the part's page led nowhere.

In message <kkf6tn+ghqn@...>, dated Sun, 14 Apr 2013, Helmut
<helmutsennewald@...> writes:

Most models from other vendors don't have Ikf at all. So the models
from OSRAM are at least as good as the models from other vendors. I
recommend to use the OSRAM models.

It isn't how good the models are that is bugging me; it's the unreality
of giving the parameters to so many significant figures. I suspect that
if tolerances were added we would see:

IKF = 392.8188163 +/-1%,

so that only a value of 393 is justified, given a range of 388.9 to
396.7. But even if the tolerance is 0.1%, the same argument applies; to
state 10 figures is meaningless.

But it's hardly a matter of outstanding global importance.
--
OOO - Own Opinions Only. See www.jmwa.demon.co.uk
They took me to a specialist burns unit - and made me learn 'To a haggis'.

John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK

--- In LTspice@..., John Woodgate <jmw@...> wrote:

In message <kkf6tn+ghqn@...>, dated Sun, 14 Apr 2013, Helmut
<helmutsennewald@...> writes:

Most models from other vendors don't have Ikf at all. So the models
from OSRAM are at least as good as the models from other vendors. I
recommend to use the OSRAM models.

It isn't how good the models are that is bugging me; it's the unreality
of giving the parameters to so many significant figures. I suspect that
if tolerances were added we would see:

IKF = 392.8188163 +/-1%,

so that only a value of 393 is justified, given a range of 388.9 to
396.7. But even if the tolerance is 0.1%, the same argument applies; to
state 10 figures is meaningless.

But it's hardly a matter of outstanding global importance.

John,

Get over it. Of course, it is silly to specify any parameters to 10 digits, but so what? I'm sure Ikf varies by +/-25%, but so what?

Rick

In message <kkf8qp+pa6i@...>, dated Sun, 14 Apr 2013, sawreyrw <sawreyrw@...> writes:

Get over it.

It's well-known to be incurable.
--
OOO - Own Opinions Only. See www.jmwa.demon.co.uk
They took me to a specialist burns unit - and made me learn 'To a haggis'.

John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK