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Bus powered means device that only use Vbus of USB for it's power supply. I want to use micro USB as my board power supply. The is designed to take 600mA by 3.3v regulator. But I just don't know how to behave to it's pins? I have found somewhere that, it's data pins must shorted or connected together through 0-200 ohm resistor.

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What and why must be exactly it's resistor?

How must be behaved to it's "shield" and "ID" pins? GND must be simply gnd isn't that?

how it will behave to charger and PCs?

Update:

I've found some nice theory about chargers beacon, for telling to hosts: I have XmA (X is variable) current available. Then they adapt themselves to accept that power. It means host will detect chargers available power.

But I want my board to beacon to the host like this: Hey host I want lot's of power please give me 1.5A (dedicated charge port) if possible.

Charger beacon types Ok, but my question is on the suppliant side not the supplier.I want good wiring configuration for:

(1)Ability to take required current from every supply including PCs without digital enumeration through MCU. (And is there any wiring config to get ride of enumeration?) (2)Nice noise, EMI, EMC performance

I've also asked my question in other form here.

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    \$\begingroup\$ You're over thinking this. For 600 mA draw and personal use, just wire it up and be careful that you only plug it into "charger" supplies of sufficient rating. Pretty obviously you are not making a product to sell to others, or at least you should not be as are nowhere near ready to do so. \$\endgroup\$ – Chris Stratton Dec 22 '18 at 23:20
  • \$\begingroup\$ @ChrisStratton Yes this is prototype for learning, But if I connected it to PC USB then what will happening? this will go to suspend mode, isn't? \$\endgroup\$ – mohammadsdtmnd Dec 23 '18 at 10:48
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This is a bit of misunderstanding. The short between D+ and D- (resistor less than 200 Ohms) is the signature of USB Battery Charging 1.2 Dedicated Charging Port on the SIDE OF CHARGER. On device (consumer) side you don't need this. In best case you should attempt to detect the short in order to determine if the port is capable of charging above the default USB power (500 mA or 900 mA).

ID has no relevance in the case of device, and shield can be safely tied with ground.

If your device consumes up to 600 mA at 3.3 V, you can design a switching-type voltage regulator (SMPS buck converter) instead of LDO. The SMPS will transform consumed current, so on the 5-V side it will consume under 500 mA (accounting for 85-90% efficiency). In this case you should not worry about USB port limitations, and your device will be happy with nearly any USB port.

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  • \$\begingroup\$ Thx for answer. (1) you mean: D+/D- wiring is in supply(charger or PC) side and states how it can provide a current to the device. Finally there is no beacon in the device to tell the supply: I am compatible for XA of current? (2) Is there any recommendation for state of "ID", in charger mod, to float it or resistor/short it to gnd/vcc? \$\endgroup\$ – mohammadsdtmnd Dec 21 '18 at 8:33
  • \$\begingroup\$ @mohammadsdtmnd, (1) - yes, bur not sure what your "XA" is; (2) ID pin in classic USB is always an input, it was meant to discriminate between micro-A and micro-B type of plugs, and was never "propagated" from source to destination, unlike CC wires in newer Type-C connection standard. Leave ID unconnected. \$\endgroup\$ – Ale..chenski Dec 21 '18 at 20:11
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    \$\begingroup\$ For correctness: 500mA is allowed only after enumeration — the idea is that a hub that itself only has 500mA on the input side will reject configuring your device because it would run out. \$\endgroup\$ – Simon Richter Dec 22 '18 at 16:31
  • \$\begingroup\$ XA meant desirable amount of X current value in A(ampere). But I've heard: Do not leave any pin float, (1) still you think I must leave it float? (2) How I must enumerate for desired current? is it possible with MCU? I've tried to learn enumeration from USB_2 specs from USB-IF but I can't find @USB Interface Power Management Specification@ as it told: "The INTERFACE_POWER descriptor is defined in the current revision of the USB Interface Power Management Specification."? (3) The only way to give desired current from host is digitally enumerating? sorry because of long story! \$\endgroup\$ – mohammadsdtmnd Dec 22 '18 at 16:53
  • \$\begingroup\$ As I think I had badly explained my question if you think it`s better to split the question I will appreciate it. \$\endgroup\$ – mohammadsdtmnd Dec 22 '18 at 17:02
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What and why must be exactly it's resistor?

See this post, in short it is for fast charging. This is beyond the original spec of 500mA for USB so YMMV.

How must be behave to it's "shield" and "ID" pins? GND must be simply gnd isn't that?

ID is for USB "On the go" (OTG) and detection of a device or host. Shield connects to the outer conductor of the cable or shield. The shield is to be connected to the chassis (in general if you have one). It can also be tied to ground, but this can also create problems, so you'd need to do some EMC research depending on what your device actually is.

how it will behave to charger and PCs?

PC's can only source 500mA, fast chargers can source more.

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  • \$\begingroup\$ Thx for answer. (1) you mean: D+/D- wiring is in supply(charger or PC) side and states how it can provide a current to the device. Finally there is no beacon in the device to tell the supply: I am compatible for XA of current? (2) Is there any recommendation for state of "ID", in charger mod, to float it or resistor/short it to gnd/vcc? \$\endgroup\$ – mohammadsdtmnd Dec 21 '18 at 8:33

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