Maximaler Strom micro USB an Handy

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Fäbu schrieb:
> Jörg W. schrieb:
>> Hab' gerade mal in die OTG Spec geschaut: Gefordert sind minimal 8 mA,
>> die das A-Device liefern können muss.  Damit würde ich meine obige
>> Aussage revidieren.
>
> Perfekt, vielen Dank.

Das heißt aber natürlich nicht, dass es nicht auch mehr liefern
könnte.

Allerdings saugst du natürlich dann ratz-batz die Batterie leer.
#4771008
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Laut OTG Spec
1
An unconfigured OTG or SRP-capable peripheral-only B-device shall draw an
2
average current of less than IB_UNCFG max current from VBUS. Current is
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averaged over a time of TAVG_VBUS.
Wobei IB_UNCFG 2,5mA max ist.

Das A-Device (also der Host) muss mindestens 8mA liefern. Mit der 
Fußnote
1
8mA is the minimum value sufficient to signal the presence of VBUS.
2
Practical implementations are likely to need a select a value of
3
IA_VBUS_RATED much higher than this minimum value. Note: at least 100mA is
4
allowed to be drawn by an unconfigured [USB2.0] peripheral.
A-device V_BUS Characteristics
1
After starting to drive VBUS, an A-device shall continue to drive VBUS for
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a time of TA_WAIT_BCON. This ensures an attached B-device has time to
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connect (see Section 5.1.1).
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After configuring a B-device, for any steady state load current that is
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less than the rated current of the A-device (IA_VBUS_RATED), the average
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output voltage from an A-device shall be within VA_VBUS_AVG_LO
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(IA_VBUS_RATED ≤ 100mA) or VA_VBUS_AVG_HI (100mA < IA_VBUS_RATED). Voltage
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is averaged over a time of TAVG_VBUS, and includes any transient voltages
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due to step changes in current.
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For a step change in load current with any amplitude less than or equal to
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the rated current of the A-device (IA_VBUS_RATED), and an edge rate of less
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than 100mA/usec, the transient output voltage from an A-device shall remain
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within VA_VBUS_TRNS_LO (IA_VBUS_RATED ≤ 100mA) or VA_VBUS_TRNS_HI (100mA <
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IA_VBUS_RATED).

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