Hi,
Being new to electronics, I often come across specs that I do not understand in catalogues and datasheets.
I would like to get some photointerrupters - H22A1, H22A2, or H22A3. In the datasheet specs there is the term Ic(on) or on-state collector current. Could someone tell me what this means? The more expensive device has a higher minimun on-state collector current. What does this mean? How is this spec used?
Thanks for any input.

dfro

 

Hi Dfro,
The Ic(on) value is the minimum load current guaranteed through the output transistor, for a given forward current in the input LED. The temperature is also given in this, normally 25 C

If you look through the datasheet the Ic(on) change when the input current through the LED change. The graphs will also tell you how the Ic(on) changes at the different temperatures.

TOK

 

Thanks Gorgon.

I think I get it. If 30mA is going through the LED and no object is blocking the light that is crossing the gap, then a guaranteed minimum of at least 5.5 mA will pass through the transistor side. Correct? I think it make sense to pay a few more cents for the H22A3 - the photointerrupter with the transistor that has the highest sensitivity to the IR light.

Thanks again,

dfro