clarify 2370332 MC65 OEM 21 Do we have a official written document explaining that MC65 in USB Host mode can draw max 100ma. customer get's this warning: " Warning! Usb host current over 100mA. Please, remove the Device!! " The message is obtained by setting the MC65 in host mode (Pin 1 and 2 tied to Pin 7: ground) and draining approx. 300mA current between Pin 7 and pin 4 (USB_VCC) and increasing slightly. already explained that this is the design of ES400- MC65 but they insist on a official statement.
MC65 USB Host max power// Expert user has replied. |
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so is a SPR needed for MC65 then to get ride of this message ? " Warning! Usb host current over 100mA. Please, remove the Device!! "
Thanks for the answer! No other suggestions here.
obviously there seems to be a communication breakdown somewhere down the line PM Dawn Fennesy was contacted by TA and is now saying Engineering confirmed that MC65 has 300mah USB max power.
Engineering told me, twice, MC65 can provide with 300mA.
Brno support told me the opposite - 100mA
I Replied that USB Host mode is limited to 100 mah but can we get some uniform answer somewhere detailed posted ? thanks
Answer from dev team:
MC65 is 300mA.
ES400 is 100mA Dave
Herbert, Are you saying that a customer is messing around with pins putting a short or load between different pins to test this? Shouldn't this void that customer's warrenty? We are designed to attach to USB devices. The customer could potentially break something doing this! Dave
Hello Dave, i agree, That statement is also part of my answers and we always advice TA's to go for CPR or for GRIP requests and not do these kind of experiments themselves for customized cables or cradles. as they will void warranty or will find them unsupported with certain 'home made' cables afterwards. But a lot of them dont give up and keep asking for questions like this. in this case they want Host Mode with a snapon cable and we only offer the singleslot with RDUYS08220007 adapter (USB host mode adaptor) if you have otherways to convince them i am happy for suggestions.
Steve Cundy replied by email:
Yes, the USB 2.0 Specification (attached), Section 7.2.1 (page 171) clearly states the maximum current draw for
bus-powered USB devices, which is one unit load (defined to be 100 ma), unless the bus-powered
USB device is a Hub, in which case it may negotiate for up to five unit loads during configuration. will provide that extract of USB 2.0 spec to the customer as an answer.