Fast, efficient IR LEDs?
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From: Phil Hobbs on 5 Feb 2010 11:56 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
From: Fred Bartoli on 5 Feb 2010 12:08 Phil Hobbs a �crit : > 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.
From: John Larkin on 5 Feb 2010 12:25 On Fri, 05 Feb 2010 11:56:15 -0500, Phil Hobbs <pcdhSpamMeSenseless(a)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
From: Phil Hobbs on 5 Feb 2010 13:25 On 2/5/2010 12:25 PM, John Larkin wrote: > On Fri, 05 Feb 2010 11:56:15 -0500, Phil Hobbs > <pcdhSpamMeSenseless(a)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
From: Joerg on 5 Feb 2010 13:37
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? http://www.texas-photonics.com/txpi1000_datasheet.pdf > 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. |