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I am using a 74HC4066 IC to switch on and off strings of LED. If I read the documentation correctly, each 'switch' in the IC can handle 25 ma. Is this correct? Also, does this mean that the entire chip (with 4 switched) can handle a combined amperage of 100ma (if all 4 switches were on at once?)

If I need more than 25 ma, can I combine 2 switching units in parallel?

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To answer your question with your current approach (total current sink capacity), you will have to pay attention to the safe operating area (SOA) of the device. The datasheet you referenced has different 'on-resistance" (RDS_ON) for various operating points.

I would say that the current would not share exactly equally if you would like to switch one main bus with multiple switches in parallel.

For higher currents, I would recommend a logic-level MOSFET, which have Vgs_th of 1-2V, so a microcontroller with 3.3V logic levels can drive the gates easily.

The advantages are 1. It is smaller (you can find an N channel logic level MOSFET in a SOT-23 package) 2. You can carry more current than 25mA (typically in the hundreds of mA).

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