Reported by Joerg Reisenweber, Nov 20, 2013
Steps to reproduce the problem: 1.search for OSRAM SFH-7740-Z Expected result: Mousser offers component Actual result: Mousser says "obsolete" http://de.rs-online.com/web/p/products/6655570/?cm_mmc=DE-PPC-0411-_- google-_-3_Supplier+M-Z+07+2012-_-SFH+7740_Phrase&gclid=CNPjq-jG8 7oCFUNe3godwBcADg http://it.mouser.com/ProductDetail/OSRAM-Opto-Semiconductors/SFH-7740 -Z/?qs=K5ta8V%252bWhtZejLNwalp0XQ== see also SFH 7741-Z
Comment 1 by Joerg Reisenweber, Nov 20, 2013
Comment 2 by Joerg Reisenweber, Nov 20, 2013
http://www.digikey.com/product-detail/en/SFH 7741-Z/475-2663-1-ND/1893865?cur=USD seems right component. Seems also available, despite OSRAM says "obsolete"
Comment 3 by Joerg Reisenweber, Nov 20, 2013
According to http://photonics.com/Article.aspx?AID=33439 I suspect we have 7740 for camdoor slider. This seems not in line with the datashhets and Rprog in N900 schematics.
Comment 4 by Nikolaus Schaller, Nov 25, 2013
Yes, the 7740 looks quite like the one used. But what I wonder is why there is a proximity sensor at all. The main purpose should be to detect if the handset is hold to an ear and turn off speakers and display/keypad backlight. This means a sensor mounted in the display assembly. And not one near the camera? Or did they simply use two of them in lack of some simpler sensor.
Comment 5 by Joerg Reisenweber, Nov 25, 2013
There are 2 similar proximity sensors, one in display half next to front camera [reflective optical switch N1540] with "incorrect" Rprog [R1541 150R], to detect when you hold phone to ear, to lock touchscreen and thus avoid false keypresses and to dim backlight. And a similar one [N5820 Main Camera Cover Switch] (though with a different "correct" Rprog [R5820 470R]) for sensing the black/white stripe on cam-door
Comment 6 by Joerg Reisenweber, Nov 25, 2013
operating range of the front proxi is ~30mm so it kicks in before you touch the screen with your ear. The operating distance of main cam cover(door) switch is in the range of 1..2mm from sensor to black/white stripe on cam door inner side. AIUI the difference between 7741 and 7740 is for the distance they are designed for, according to http://photonics.com/Article.aspx?AID=33439. Rprog is another means to determine operation distance, however 150R is not mentioned as valid vakue in the datasheet I have.
Comment 7 by Joerg Reisenweber, Nov 25, 2013
My suspicion is that they obsoleted the 7740 since the 7741 is doing the job just good enough to replace 7740
Comment 8 by Nikolaus Schaller, Dec 14, 2020