EEVblog Electronics Community Forum
Electronics => Beginners => Topic started by: ledtester on September 23, 2020, 07:03:26 pm
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I was wondering if an analog switch such as the TS3A5018 (datasheet) (https://www.ti.com/document-viewer/TS3A5018/datasheet) would be suitable for switching the SDIO/SPI interface lines between two SD cards.
In this case data is written to the SD card at about 100 MB/minute.
The datasheet says the bandwidth of the TS3A5018 is 300 MHz into a 50R load. Would that also be indicative of its performance in this application?
This is an idea to off-load data from a camera by electronically switching between two SD cards.
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Why analog. Do you want to send over fixed impedance line? Why not a digital transceiver. The SD cards on arduino breakouts commonly rely on LVC245A.
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Can't they both share the bus and just use the SS Slave Select line?
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Can't they both share the bus and just use the SS Slave Select line?
I want to access the other card from another microcontroller. And I can't modify the firmware of the camera.
Why analog. Do you want to send over fixed impedance line? Why not a digital transceiver. The SD cards on arduino breakouts commonly rely on LVC245A.
It could be done with 4 transceiver chips. Possibly could be done with 2 if I give up the ability of independent HI-Z control.
Think of it as a camera writing to card #1. Then it is redirected to write to card #2 while a microcontroller connects to card #1 to process the data. And then another switch happens, etc.
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Yes, analog switches can be used as digital multiplexers in most digital applications and may even be preferred in some cases.