Anyone ID this Ambient Light Sensor, link to photo

[Grant]

Hi there,

I cannot find the part number for this ambient light sensor. Seen some like
it, which helped me match up the wiring diagram net names, scl and sda serial
comms interface... to a light sensor? If I hadn't seen similar ones in online
catalogs I'd not expect it.

Photo of the little beastie is here:

http://grrr.id.au/image/AmbientLightSensor.jpg

Came out of an incomplete Samsung LCD TV given to me for parts recently, it's
mounted on the same PCB as the IR receiver, but is definitely not a LED, I
probed around it and got no light out of it. There's blue LEDs around the
power switch, on another PCB.

If I knew the part, I could perhaps use the thing.

Thanks,
Grant.

 

[Charlie E.]

Nose around Avago or TAOS sites. (I've done some device modeling for
them, but I'm not really familiar with their whole line-up.)

...Jim Thompson

Do a google for digital ambient light sensor and you should find a set
of results that will help you find it. Most of these are 6 pin
devices, and I only really see four here. Sure it is digital?

Charlie

 

[JB]

There are some newer TAOS devices which are 4-pin. Near human eye-response
ambient light in Lux to I2C.
JB

 

[Grant]

Do a google for digital ambient light sensor and you should find a set
of results that will help you find it. Most of these are 6 pin
devices, and I only really see four here. Sure it is digital?

Pretty sure, here's the other end of the wiring loom, labeled:

http://grrr.id.au/image/AmbientLightSensorWiring.jpg

For the IR + photosensor board we have 5V, Gnd, IR, SCL2 and SDA2, and those
last two lines connect top the sensor via series 100 ohm and a cap.

I don't have anything here setup to monitor the digital lines, I saw a hint in
the wiring diagram clock may've been run from H. Sync, but I didn't get the main
logic card, so it's all guesswork. The main wiring shows many pairs of SCL + SDA
going around the place so their main chip doesn't address them directly.

Then again I did see a '4051, so perhaps the data lines selected through that?

And yes, my searching for digital light sensors only turned up the 6pin sensors,
so this might be some obscure Korean thing? Doesn't matter, I was looking for
an analog or PWM brightness signal, to feed the lightbox*, I'll try it with a 1k
pot across 3.3V first, make a PWM only if I have to. All I know is that the
DIM signal feeds a 120k resistor, some passive network then into an inverter
control IC for which I can only find a summary datasheet, no application note
or typical connection diagram. BD9886FV for the curious.

* Recovered lightbox from half an LCD TV, ripped the LCD panel out, just want
to run the CCFL lights. 1360 x 768 x 32" panel is not much good as a display
replacement for a recently acquired laptop with busted LCD

Grant.

 

[Grant]

There are some newer TAOS devices which are 4-pin. Near human eye-response
ambient light in Lux to I2C.

Bingo! Four lead SMD: Vcc, Gnd, SMBData, SMBClk TLS2550! It's a start,
and does look possible.

Grant.