Fast, efficient IR LEDs?

Phil Hobbs
Guest

Fri Feb 05, 2010 6:56 pm

I need a fast IR LED (> 20 MHz, < 50 pF) for an optical feedback gizmo.
I have some Stanley DN310s, but they've been discontinued. Other
possibilities are:

Vishay TSFF5410 -- 870 nm, 0.% W/A typ 15 ns rise/fall, 125 pF typ
Vishay VSLB3940 -- 940 nm, 0.4 W/A typ 15 ns rise/fall, 70 pF typ
Panasonic LNA4905L -- 880 nm, 0.3 W/A min 30 MHz typ, no other specs
Osram SFH4550 -- 850 nm, 0.5 W/A typ 12 ns rise/fall, no C spec

It would be really nice to find something with a flat front facet and
(especially) lower capacitance, because it has to work at quite low
currents (5-10 uA).

Any suggestions?

Thanks

Phil Hobbs

PS: Amazing how we're actually talking about electronics at the moment!

--
Dr Philip C D Hobbs
Principal
ElectroOptical Innovations
55 Orchard Rd
Briarcliff Manor NY 10510
845-480-2058
hobbs at electrooptical dot net
http://electrooptical.net

Fred Bartoli
Guest

Fri Feb 05, 2010 7:08 pm

Phil Hobbs a écrit :

Quote:

I need a fast IR LED (> 20 MHz, < 50 pF) for an optical feedback gizmo.
I have some Stanley DN310s, but they've been discontinued. Other
possibilities are:

Vishay TSFF5410 -- 870 nm, 0.% W/A typ 15 ns rise/fall, 125 pF typ
Vishay VSLB3940 -- 940 nm, 0.4 W/A typ 15 ns rise/fall, 70 pF typ
Panasonic LNA4905L -- 880 nm, 0.3 W/A min 30 MHz typ, no other specs
Osram SFH4550 -- 850 nm, 0.5 W/A typ 12 ns rise/fall, no C spec

It would be really nice to find something with a flat front facet and
(especially) lower capacitance, because it has to work at quite low
currents (5-10 uA).

Any suggestions?

Thanks

Phil Hobbs

PS: Amazing how we're actually talking about electronics at the moment!

Shh. Don't feed the Jiant Troll :-)

--
Thanks,
Fred.

John Larkin
Guest

Fri Feb 05, 2010 7:25 pm

On Fri, 05 Feb 2010 11:56:15 -0500, Phil Hobbs
<pcdhSpamMeSenseless_at_electrooptical.net> wrote:

Quote:

I need a fast IR LED (> 20 MHz, < 50 pF) for an optical feedback gizmo.
I have some Stanley DN310s, but they've been discontinued. Other
possibilities are:

Vishay TSFF5410 -- 870 nm, 0.% W/A typ 15 ns rise/fall, 125 pF typ
Vishay VSLB3940 -- 940 nm, 0.4 W/A typ 15 ns rise/fall, 70 pF typ
Panasonic LNA4905L -- 880 nm, 0.3 W/A min 30 MHz typ, no other specs
Osram SFH4550 -- 850 nm, 0.5 W/A typ 12 ns rise/fall, no C spec

It would be really nice to find something with a flat front facet and
(especially) lower capacitance, because it has to work at quite low
currents (5-10 uA).

Any suggestions?

Thanks

Phil Hobbs

PS: Amazing how we're actually talking about electronics at the moment!

Maybe use a visible part? They seem to get the most development effort
lately. I'll measure the capacitance on some of the right-angle
surface-mount Osram parts we use. They are blindingly bright, clearly
on at 1 uA in normal office lighting.

The red response of a silicon detector isn't much below the IR peak.

And now, back to politics...

John

Phil Hobbs
Guest

Fri Feb 05, 2010 8:25 pm

On 2/5/2010 12:25 PM, John Larkin wrote:

Quote:

On Fri, 05 Feb 2010 11:56:15 -0500, Phil Hobbs
pcdhSpamMeSenseless_at_electrooptical.net> wrote:

I need a fast IR LED (> 20 MHz,< 50 pF) for an optical feedback gizmo.
I have some Stanley DN310s, but they've been discontinued. Other
possibilities are:

Vishay TSFF5410 -- 870 nm, 0.% W/A typ 15 ns rise/fall, 125 pF typ
Vishay VSLB3940 -- 940 nm, 0.4 W/A typ 15 ns rise/fall, 70 pF typ
Panasonic LNA4905L -- 880 nm, 0.3 W/A min 30 MHz typ, no other specs
Osram SFH4550 -- 850 nm, 0.5 W/A typ 12 ns rise/fall, no C spec

It would be really nice to find something with a flat front facet and
(especially) lower capacitance, because it has to work at quite low
currents (5-10 uA).

Any suggestions?

Thanks

Phil Hobbs

PS: Amazing how we're actually talking about electronics at the moment!

Maybe use a visible part? They seem to get the most development effort
lately. I'll measure the capacitance on some of the right-angle
surface-mount Osram parts we use. They are blindingly bright, clearly
on at 1 uA in normal office lighting.

The red response of a silicon detector isn't much below the IR peak.

And now, back to politics...

John

I looked, but I haven't found any with speed and capacitance specs. If
you can find any that are quick and have an output of above 0.5 W/A,
that would be perfect. (Because each photon has more energy, you need
more photons for a given photocurrent, and it's a photocurrent that's
the desired output--it's sort of a special-purpose dorked optocoupler.
Smaller would be good too.

The IR ones have been really bright for awhile--the 15-year-old DN401s
(corrected P/N) are very nearly as efficient as the newest ones, and
only a factor of 2 slower. The IRDA application is why they need speed
specs, and nobody does IRDA in the visible.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal
ElectroOptical Innovations
55 Orchard Rd
Briarcliff Manor NY 10510
845-480-2058
hobbs at electrooptical dot net
http://electrooptical.net

Joerg
Guest

Fri Feb 05, 2010 8:37 pm

Phil Hobbs wrote:

Quote:

I need a fast IR LED (> 20 MHz, < 50 pF) for an optical feedback gizmo.
I have some Stanley DN310s, but they've been discontinued. Other
possibilities are:

Vishay TSFF5410 -- 870 nm, 0.% W/A typ 15 ns rise/fall, 125 pF typ
Vishay VSLB3940 -- 940 nm, 0.4 W/A typ 15 ns rise/fall, 70 pF typ
Panasonic LNA4905L -- 880 nm, 0.3 W/A min 30 MHz typ, no other specs
Osram SFH4550 -- 850 nm, 0.5 W/A typ 12 ns rise/fall, no C spec

It would be really nice to find something with a flat front facet and
(especially) lower capacitance, because it has to work at quite low
currents (5-10 uA).

Any suggestions?

This one is too big, too much capacitance, but they have smaller plastic
versions, maybe give them a ring?

http://www.texas-photonics.com/txpi1000_datasheet.pdf

Quote:

Thanks

Phil Hobbs

PS: Amazing how we're actually talking about electronics at the moment!

That can change in milliseconds :-)

--
Regards, Joerg

http://www.analogconsultants.com/

"gmail" domain blocked because of excessive spam.
Use another domain or send PM.

John Larkin
Guest

Fri Feb 05, 2010 8:45 pm

On Fri, 05 Feb 2010 09:25:28 -0800, John Larkin
<jjlarkin_at_highNOTlandTHIStechnologyPART.com> wrote:

Quote:

On Fri, 05 Feb 2010 11:56:15 -0500, Phil Hobbs
pcdhSpamMeSenseless_at_electrooptical.net> wrote:

I need a fast IR LED (> 20 MHz, < 50 pF) for an optical feedback gizmo.
I have some Stanley DN310s, but they've been discontinued. Other
possibilities are:

Vishay TSFF5410 -- 870 nm, 0.% W/A typ 15 ns rise/fall, 125 pF typ
Vishay VSLB3940 -- 940 nm, 0.4 W/A typ 15 ns rise/fall, 70 pF typ
Panasonic LNA4905L -- 880 nm, 0.3 W/A min 30 MHz typ, no other specs
Osram SFH4550 -- 850 nm, 0.5 W/A typ 12 ns rise/fall, no C spec

It would be really nice to find something with a flat front facet and
(especially) lower capacitance, because it has to work at quite low
currents (5-10 uA).

Any suggestions?

Thanks

Phil Hobbs

PS: Amazing how we're actually talking about electronics at the moment!

Maybe use a visible part? They seem to get the most development effort
lately. I'll measure the capacitance on some of the right-angle
surface-mount Osram parts we use. They are blindingly bright, clearly
on at 1 uA in normal office lighting.

The red response of a silicon detector isn't much below the IR peak.

And now, back to politics...

John

http://catalog.osram-os.com/catalogue/catalogue.do;jsessionid=6AC83F9F110FC71BC37646EE19F1BDDE?act=downloadFile&favOid=0200000200003436000100b6

I measured a red one of these at 9 pF, orange at 13.5. I have no idea
what the optical power output may be, or the ctr you can get into a
silicon detector. We consider 5 mA to be "bright" on the red and
green, 10 mA for the orange and blues. "Dim" is 1/10th that.

These are really nice led's. The colors are bright and pure, the
orange being especially nice looking. And they are dual-shot moulded,
so they don't melt when you solder them.

John

Phil Hobbs
Guest

Fri Feb 05, 2010 9:38 pm

On 2/5/2010 1:45 PM, John Larkin wrote:

Quote:

On Fri, 05 Feb 2010 09:25:28 -0800, John Larkin
jjlarkin_at_highNOTlandTHIStechnologyPART.com> wrote:

On Fri, 05 Feb 2010 11:56:15 -0500, Phil Hobbs
pcdhSpamMeSenseless_at_electrooptical.net> wrote:

I need a fast IR LED (> 20 MHz,< 50 pF) for an optical feedback gizmo.
I have some Stanley DN310s, but they've been discontinued. Other
possibilities are:

Vishay TSFF5410 -- 870 nm, 0.% W/A typ 15 ns rise/fall, 125 pF typ
Vishay VSLB3940 -- 940 nm, 0.4 W/A typ 15 ns rise/fall, 70 pF typ
Panasonic LNA4905L -- 880 nm, 0.3 W/A min 30 MHz typ, no other specs
Osram SFH4550 -- 850 nm, 0.5 W/A typ 12 ns rise/fall, no C spec

It would be really nice to find something with a flat front facet and
(especially) lower capacitance, because it has to work at quite low
currents (5-10 uA).

Any suggestions?

Thanks

Phil Hobbs

PS: Amazing how we're actually talking about electronics at the moment!

Maybe use a visible part? They seem to get the most development effort
lately. I'll measure the capacitance on some of the right-angle
surface-mount Osram parts we use. They are blindingly bright, clearly
on at 1 uA in normal office lighting.

The red response of a silicon detector isn't much below the IR peak.

And now, back to politics...

John

http://catalog.osram-os.com/catalogue/catalogue.do;jsessionid=6AC83F9F110FC71BC37646EE19F1BDDE?act=downloadFile&favOid=0200000200003436000100b6

I measured a red one of these at 9 pF, orange at 13.5. I have no idea
what the optical power output may be, or the ctr you can get into a
silicon detector. We consider 5 mA to be "bright" on the red and
green, 10 mA for the orange and blues. "Dim" is 1/10th that.

These are really nice led's. The colors are bright and pure, the
orange being especially nice looking. And they are dual-shot moulded,
so they don't melt when you solder them.

John

Hmm, interesting. The red ones specify about 7 lumens/W at 635 nm. The

photopic response there is about 22% of the peak value, or 138 lumens/W,
which makes these ones about 0.05 mW/mA, which is a bit on the low side.
I definitely like the capacitance though!

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal
ElectroOptical Innovations
55 Orchard Rd
Briarcliff Manor NY 10510
845-480-2058
hobbs at electrooptical dot net
http://electrooptical.net

John Larkin
Guest

Fri Feb 05, 2010 9:43 pm

On Fri, 5 Feb 2010 11:13:02 -0800 (PST), "miso_at_sushi.com"
<miso_at_sushi.com> wrote:

Quote:

On Feb 5, 8:56 am, Phil Hobbs <pcdhSpamMeSensel...@electrooptical.net
wrote:
I need a fast IR LED (> 20 MHz, < 50 pF) for an optical feedback gizmo.
I have some Stanley DN310s, but they've been discontinued. Other
possibilities are:

Vishay TSFF5410 -- 870 nm, 0.% W/A typ 15 ns rise/fall, 125 pF typ
Vishay VSLB3940 -- 940 nm, 0.4 W/A typ 15 ns rise/fall, 70 pF typ
Panasonic LNA4905L -- 880 nm, 0.3 W/A min 30 MHz typ, no other specs
Osram SFH4550 -- 850 nm, 0.5 W/A typ 12 ns rise/fall, no C spec

It would be really nice to find something with a flat front facet and
(especially) lower capacitance, because it has to work at quite low
currents (5-10 uA).

Any suggestions?

Thanks

Phil Hobbs

PS: Amazing how we're actually talking about electronics at the moment!

--
Dr Philip C D Hobbs
Principal
ElectroOptical Innovations
55 Orchard Rd
Briarcliff Manor NY 10510
845-480-2058
hobbs at electrooptical dot nethttp://electrooptical.net

Isn't low current and high speed mutually exclusive, like intelligence
and Republicans?

Ah, politics!

I wonder why lefties always assume that conservatives are stupid.
That's the "what's wrong with Kansas?" dilemma, the lament that the
working class won't toe the party line and follow the lead of their
betters.

Conservatives generally assume that lefties are both stupid and evil.

John

John Larkin
Guest

Fri Feb 05, 2010 9:46 pm

On Fri, 05 Feb 2010 14:38:32 -0500, Phil Hobbs
<pcdhSpamMeSenseless_at_electrooptical.net> wrote:

Quote:

On 2/5/2010 1:45 PM, John Larkin wrote:
On Fri, 05 Feb 2010 09:25:28 -0800, John Larkin
jjlarkin_at_highNOTlandTHIStechnologyPART.com> wrote:

On Fri, 05 Feb 2010 11:56:15 -0500, Phil Hobbs
pcdhSpamMeSenseless_at_electrooptical.net> wrote:

I need a fast IR LED (> 20 MHz,< 50 pF) for an optical feedback gizmo.
I have some Stanley DN310s, but they've been discontinued. Other
possibilities are:

Vishay TSFF5410 -- 870 nm, 0.% W/A typ 15 ns rise/fall, 125 pF typ
Vishay VSLB3940 -- 940 nm, 0.4 W/A typ 15 ns rise/fall, 70 pF typ
Panasonic LNA4905L -- 880 nm, 0.3 W/A min 30 MHz typ, no other specs
Osram SFH4550 -- 850 nm, 0.5 W/A typ 12 ns rise/fall, no C spec

It would be really nice to find something with a flat front facet and
(especially) lower capacitance, because it has to work at quite low
currents (5-10 uA).

Any suggestions?

Thanks

Phil Hobbs

PS: Amazing how we're actually talking about electronics at the moment!

Maybe use a visible part? They seem to get the most development effort
lately. I'll measure the capacitance on some of the right-angle
surface-mount Osram parts we use. They are blindingly bright, clearly
on at 1 uA in normal office lighting.

The red response of a silicon detector isn't much below the IR peak.

And now, back to politics...

John

http://catalog.osram-os.com/catalogue/catalogue.do;jsessionid=6AC83F9F110FC71BC37646EE19F1BDDE?act=downloadFile&favOid=0200000200003436000100b6

I measured a red one of these at 9 pF, orange at 13.5. I have no idea
what the optical power output may be, or the ctr you can get into a
silicon detector. We consider 5 mA to be "bright" on the red and
green, 10 mA for the orange and blues. "Dim" is 1/10th that.

These are really nice led's. The colors are bright and pure, the
orange being especially nice looking. And they are dual-shot moulded,
so they don't melt when you solder them.

John

Hmm, interesting. The red ones specify about 7 lumens/W at 635 nm. The
photopic response there is about 22% of the peak value, or 138 lumens/W,
which makes these ones about 0.05 mW/mA, which is a bit on the low side.
I definitely like the capacitance though!

Cheers

Phil Hobbs

Yeah, I guess 635 isn't red enough.

John

Phil Hobbs
Guest

Fri Feb 05, 2010 9:47 pm

On 2/5/2010 1:37 PM, Joerg wrote:

Quote:

Phil Hobbs wrote:
I need a fast IR LED (> 20 MHz, < 50 pF) for an optical feedback
gizmo. I have some Stanley DN310s, but they've been discontinued.
Other possibilities are:

Vishay TSFF5410 -- 870 nm, 0.% W/A typ 15 ns rise/fall, 125 pF typ
Vishay VSLB3940 -- 940 nm, 0.4 W/A typ 15 ns rise/fall, 70 pF typ
Panasonic LNA4905L -- 880 nm, 0.3 W/A min 30 MHz typ, no other specs
Osram SFH4550 -- 850 nm, 0.5 W/A typ 12 ns rise/fall, no C spec

It would be really nice to find something with a flat front facet and
(especially) lower capacitance, because it has to work at quite low
currents (5-10 uA).

Any suggestions?

This one is too big, too much capacitance, but they have smaller plastic
versions, maybe give them a ring?

How retro. Wink

I'll do that, thanks.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal
ElectroOptical Innovations
55 Orchard Rd
Briarcliff Manor NY 10510
845-480-2058
hobbs at electrooptical dot net
http://electrooptical.net

Phil Hobbs
Guest

Fri Feb 05, 2010 9:48 pm

On 2/5/2010 2:13 PM, miso_at_sushi.com wrote:

Quote:

On Feb 5, 8:56 am, Phil Hobbs<pcdhSpamMeSensel...@electrooptical.net
wrote:
I need a fast IR LED (> 20 MHz,< 50 pF) for an optical feedback gizmo.
I have some Stanley DN310s, but they've been discontinued. Other
possibilities are:

Vishay TSFF5410 -- 870 nm, 0.% W/A typ 15 ns rise/fall, 125 pF typ
Vishay VSLB3940 -- 940 nm, 0.4 W/A typ 15 ns rise/fall, 70 pF typ
Panasonic LNA4905L -- 880 nm, 0.3 W/A min 30 MHz typ, no other specs
Osram SFH4550 -- 850 nm, 0.5 W/A typ 12 ns rise/fall, no C spec

It would be really nice to find something with a flat front facet and
(especially) lower capacitance, because it has to work at quite low
currents (5-10 uA).

Any suggestions?

Thanks

Phil Hobbs

Isn't low current and high speed mutually exclusive, like intelligence
and Republicans?

Nice try, Soup. Wink

I enjoy talking electronics too much though.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal
ElectroOptical Innovations
55 Orchard Rd
Briarcliff Manor NY 10510
845-480-2058
hobbs at electrooptical dot net
http://electrooptical.net

George Herold
Guest

Fri Feb 05, 2010 9:54 pm

On Feb 5, 11:56 am, Phil Hobbs
<pcdhSpamMeSensel...@electrooptical.net> wrote:

Quote:

I need a fast IR LED (> 20 MHz, < 50 pF) for an optical feedback gizmo.
I have some Stanley DN310s, but they've been discontinued. Other
possibilities are:

Vishay TSFF5410 -- 870 nm, 0.% W/A typ 15 ns rise/fall, 125 pF typ
Vishay VSLB3940 -- 940 nm, 0.4 W/A typ 15 ns rise/fall, 70 pF typ
Panasonic LNA4905L -- 880 nm, 0.3 W/A min 30 MHz typ, no other specs
Osram SFH4550 -- 850 nm, 0.5 W/A typ 12 ns rise/fall, no C spec

It would be really nice to find something with a flat front facet and
(especially) lower capacitance, because it has to work at quite low
currents (5-10 uA).

Any suggestions?

Thanks

Phil Hobbs

PS: Amazing how we're actually talking about electronics at the moment!

--
Dr Philip C D Hobbs
Principal
ElectroOptical Innovations
55 Orchard Rd
Briarcliff Manor NY 10510
845-480-2058
hobbs at electrooptical dot nethttp://electrooptical.net

I have no part numbers to recommend. (Sorry) But I wonder why IR
LED’s are so much more efficient than visible. (I calculate about 33%
efficiency for the 850nm at 0.5W/A.) (O.5 W/A = 0.5 eV/electron and
each photon is about 1.5 eV)

George H.

miso@sushi.com
Guest

Fri Feb 05, 2010 10:13 pm

On Feb 5, 8:56 am, Phil Hobbs <pcdhSpamMeSensel...@electrooptical.net>
wrote:

Quote:

I need a fast IR LED (> 20 MHz, < 50 pF) for an optical feedback gizmo.
I have some Stanley DN310s, but they've been discontinued. Other
possibilities are:

Vishay TSFF5410 -- 870 nm, 0.% W/A typ 15 ns rise/fall, 125 pF typ
Vishay VSLB3940 -- 940 nm, 0.4 W/A typ 15 ns rise/fall, 70 pF typ
Panasonic LNA4905L -- 880 nm, 0.3 W/A min 30 MHz typ, no other specs
Osram SFH4550 -- 850 nm, 0.5 W/A typ 12 ns rise/fall, no C spec

It would be really nice to find something with a flat front facet and
(especially) lower capacitance, because it has to work at quite low
currents (5-10 uA).

Any suggestions?

Thanks

Phil Hobbs

PS: Amazing how we're actually talking about electronics at the moment!

--
Dr Philip C D Hobbs
Principal
ElectroOptical Innovations
55 Orchard Rd
Briarcliff Manor NY 10510
845-480-2058
hobbs at electrooptical dot nethttp://electrooptical.net

Isn't low current and high speed mutually exclusive, like intelligence
and Republicans?

Joerg
Guest

Sat Feb 06, 2010 12:20 am

Phil Hobbs wrote:

Quote:

On 2/5/2010 2:13 PM, miso_at_sushi.com wrote:
On Feb 5, 8:56 am, Phil Hobbs<pcdhSpamMeSensel...@electrooptical.net
wrote:
I need a fast IR LED (> 20 MHz,< 50 pF) for an optical feedback gizmo.
I have some Stanley DN310s, but they've been discontinued. Other
possibilities are:

Vishay TSFF5410 -- 870 nm, 0.% W/A typ 15 ns rise/fall, 125 pF typ
Vishay VSLB3940 -- 940 nm, 0.4 W/A typ 15 ns rise/fall, 70 pF typ
Panasonic LNA4905L -- 880 nm, 0.3 W/A min 30 MHz typ, no other specs
Osram SFH4550 -- 850 nm, 0.5 W/A typ 12 ns rise/fall, no C spec

It would be really nice to find something with a flat front facet and
(especially) lower capacitance, because it has to work at quite low
currents (5-10 uA).

Any suggestions?

Thanks

Phil Hobbs

Isn't low current and high speed mutually exclusive, like intelligence
and Republicans?

Nice try, Soup. Wink

I enjoy talking electronics too much though.

His "email address" always makes me crave miso soup and sushi. So, we
just went to the Japanese restaurant in town ...

But this time I had pork teriyaki after the miso soup. We usually have
sushi in the evenings, I can't really work after that, it's so good that
I tend to eat too much of it.

--
Regards, Joerg

http://www.analogconsultants.com/

"gmail" domain blocked because of excessive spam.
Use another domain or send PM.

Jim Thompson
Guest

Sat Feb 06, 2010 12:25 am

On Fri, 05 Feb 2010 11:43:30 -0800, John Larkin
<jjlarkin_at_highNOTlandTHIStechnologyPART.com> wrote:

Quote:

On Fri, 5 Feb 2010 11:13:02 -0800 (PST), "miso_at_sushi.com"
miso_at_sushi.com> wrote:

[snip]

Isn't low current and high speed mutually exclusive, like intelligence
and Republicans?

Ah, politics!

I wonder why lefties always assume that conservatives are stupid.
That's the "what's wrong with Kansas?" dilemma, the lament that the
working class won't toe the party line and follow the lead of their
betters.

Conservatives generally assume that lefties are both stupid and evil.

John