Ya (or Mu suggestions)

Adam Wang adam at qi-hardware.com
Sat Aug 8 09:48:45 EDT 2009

Hi Bas & All,

Happy Father's Day.
> I would be quite unhappy with mini-B, actually.  The standard says that
> standard A or micro-A should be used.  Obviously standard A is way too
> large.
You are right on the thinking for using standard A. It's really large.
> sources, while type B connectors are power sinks (users).  The standard
> A to mini-B cables are used everywhere, for example to connect card
> readers.  It is a very good plug for the USB device function; it is
> really bad for the host function.
Yes, bad for the host design; we also faced this embarrassed scenario.
> According to wikipedia the recommendation to use micro-A as host-plug
> for small devices (actually for on-the-go devices) is supported by
> important parties, which means it will likely become a real standard.  I
> don't have enough experience (I haven't ever conciously seen a USB micro
> plug) with this type of devices to know if that claim is true, but I
> suppose others on the list do.
For those kinds of conditions we took considerations into like following 
a) If CPU supports OTG, we should use Micro-AB receptacle.
b) If CPU doesn't support OTG, meant it may has 1 channel for USB device 
and the other one for
    USB host; we should choose carefully different connectors for both 

Since your suggestions for Ya is really great to us, I posted an article 
[1] which depicted that
"How to design a circuit with usb host and device function". We'll still 
absorb all suggestions on
Ya's features and keep surveying. I do hope you still can point out if I 
was wrong in this post. :-)


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