EEVblog Electronics Community Forum
Electronics => Projects, Designs, and Technical Stuff => Topic started by: martin321 on November 28, 2015, 04:50:40 pm
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Hi,
I am trying to get the GL823 card reader to work, but there is no response from the pcb when I plug in the USB cable.
There is 3.3v DVDD, 1.5v on LED pin and nothing on PMOS or AVDD.
No resistors placed at R1 to R5.
Received the design guide and datasheet from supplier. Think I have correctly copied it.
gl823_sch.pdf is the one I have made.
If anyone could help me out I would relay appreciate it.
Martin
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Found the post linked under. Anyone that can see my error?
https://www.eevblog.com/forum/beginners/issues-with-breadboard-sd-card-reader/ (https://www.eevblog.com/forum/beginners/issues-with-breadboard-sd-card-reader/)
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There is 3.3v DVDD, 1.5v on LED pin and nothing on PMOS or AVDD.
Hint: where the power to AVDD is supposed to come from? :)
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Sorry, but I don't follow you.
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Sorry, but I don't follow you.
Do you expect AVDD to appear from nowhere :palm:? It is externally connected to the chip. On the gl823_sch.pdf through the L1 inductor from the DVDD.
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Well, DVDD does appear out of nowhere, so go figure :box:
Seriously though, page 16 of the datasheet kinda suggests that the internal 3.3V regulator outputs to DVDD and then note1 on page 12 tells that AVDD needs to be hooked up to that through a bead.