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| Any jellybean low current (<10mA) opto-mosfet or opto-ssr for signal routing ? |
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| Psi:
--- Quote from: BrianHG on February 25, 2024, 03:48:33 am ---https://www.mouser.com/ProductDetail/Toshiba/TLP175ATPLE?qs=HVbQlW5zcXXp9ILK7hvmMw%3D%3D --- End quote --- Yep. i've been looking at the TLP175A. Seems pretty good value. |
| Zero999:
Does it matter if it's normally on? It won't be the cheapest, but J-FETs typically have a lower capacitance and leakage, compared to MOSFETs, so use a photovoltaic opto-coupler and a J-FET, or two back-to-back, if it has to block in both directions. |
| BrianHG:
There is always FET output optocouplers. Since only 10ma is needed, plus you also get a linear transfer of output resistance tracking LED current. Also, using 2x regular transistor output optos with the transistors wired back-to-back offers you the same AC switch like a mosfet output. This means a jellybean 4 channel transistor out opto can be wired as if it were a 2 channel AC mosfet out opto. Though, you need to make sure your IR-led current is goo and strong. If an 8 transistor opto exists, then that will give you the equiv of a 4 channel mosfet out unit. |
| BrianHG:
Here, take a look at this guy: https://www.mouser.com/ProductDetail/Lite-On/LTV-846S?qs=sGAEpiMZZMteimceiIVCB8%252BEnxlUsvj2XjK3CA4Ts7M%3D 4 channel = 46cents for 100pcx. This means 23cents per AC channel, and you get 2 per device. The even have them in DIP16 package for 45centx for 100pcx. https://www.mouser.com/ProductDetail/Lite-On/LTV-847?qs=sGAEpiMZZMteimceiIVCB4BEdbJlF99qN8g%2Fz4u5H%2FM%3D |
| Kleinstein:
Normal transistors don't work well in the reverse direction. The breake down voltage is usually quite low. In forward direction there is a little saturation voltage of some 10 mV, even at low current. So 2 transistor optocouplers can not really replace a fet output optocoupler. |
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