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1

In general topology, a host polls or provides control to all down-level comm. channel devices. This is done by polling or listening to a channel from downstream clients. In a tree, a host (or server) is above all the clients its serves by polling or listening for a request for a channel. Thus, a Host controls all traffic on a downward facing port (DFP) and ...


7

A host is downstream-facing. As in, pointing in the direction of downstream. An upstream device looks downstream, and a downstream device looks upstream.


0

Your schematic should work but I would add one more level of protection. You can look at the common Arduinos which use the same type of circuitry. Some knock-off arduinos have a pair of pads and a tiny copper trace that can be cut and the user has to add the diode to allow 12VDC or 5vusb operation. Some arduinos have the diode in place when you buy it. But,...


0

First, please clarify what is "far from ideal"? * "however its idle consumption and power-off power draw (phantom load) is far from ideal" To come at your goal another way, check if you have an "always on" USB with something plugged into that USB port that might draw current. You can either check your bios or owners manual to ...


1

As @Justme commented, there is no way to tell if something is damaged. Just because you can see output from the device, this does not guarantee that it is intact. Most (if not all) datasheets from ICs, they mention somewhere "Absolute maximum values" of voltage, temerature and current. For example this datahseet from Si826x mosfet gate drivers: ...


6

The USB cable is a transmission line with a characteristic impedance (90 ohms nominal.) ‘Impedance matching’, in this context, means terminating the line in its characteristic impedance to avoid reflections and thus ensure good signal integrity. The USB2 DP/DM lines are half-duplex bidirectional, so need to be terminated at one end or the other, depending on ...


10

Matching the impedance does not mean just reactance matching and the transmitted data or frequency content does not matter when the impedance is properly matched. USB data lines have 90 ohm wave impedance so a transmission line with infinite length would look like a 90 ohm resistor for a DC signal that is applied forever as the electromagnetic wave travels ...


4

Because the manufacturer cheaped out. Building a USB 2 device with a USB C connector is relatively simple. You just need some resistors to tell the other end what you are doing and then the rest of the device design is the same as any other USB 2 device. Building a USB 3 device with a USB C connector is harder. In addition to the resistors, it requires ...


0

No you have the general idea down already. These boards typically have a reverse protection diode, a fuse, and a regulator in the path. When you short it any of those can go. And if you short a gpio the microcontroller can as well. The passive components to the regulator are another possibility but less so. If you can bypass the regulator by inputting 3.3V ...


2

You need to power VIO, most likely 3V3 on your case. Page 29 of the datasheet: 5 VIO I/O Supply Power Input


1

This has been answered very well, but I will just add one point: You asked, "How much power do type-c power bricks provide if there is no CC negotiation and I just connect its 5V VBUS to my charging/PMIC*?" The answer is zero. DFPs are not supposed to supply Vbus at all until they at least see some sort of pull-down resistance on one of the CCx ...


4

What you propose is not an USB hub. An USB hub is an active device and implementing it requires an IC.


2

From wikipedia: this is the USB 3.X Connections of the type A male plug: And the type 3.X type A female: D+ and D- are used for USB 2.0. All the other are used for USB 3.X. I do now know which pin broke, but you certainly need GND pin and VCC pin. After that, you need both of D+ and D- to use USB 2.0. Regarding USB 3.0, I am not sure which pins you can ...


0

You transfer the data to the EzUSB, where it is buffered until the host picks it up. Since the host determines the time when the transfer is started, you cannot really avoid the buffer in this direction.


0

You'll want an easy way to switch to using either data pair. In the easiest case, your microcontroller's IO matrix is flexible enough to route either one or another pair of pins to the internal USB PHY, or you have two USB PHYs. Most MCUs don't have that. Instead, a very simple switch IC can be used, controlled by which of both USB ports has external VUSB ...


1

Using two sockets on the same bus seems like a poor idea, both because of signal integrity (each socket's routing ends up becoming a long stub when the other is in use) and the risk of hardware damage if someone does plug both ports in (especially if they share VBUS). Instead, consider the use of a USB switch IC similar to the ones in the USB portion of KVM ...


34

Generally speaking, unused PCIe data lanes should be left unterminated. This will apply to mini-PCIe as well. PCIe transmitters use a receiver detection scheme which looks for a the termination impedance of the receivers to determine whether or not anything is connected. If no termination is detected, the transmitters are placed in an electrical idle state ...


2

USB 1/2 has four wires, Ground, Power and a differential pair for communications. Mini and micro connectors add a fifth pin, "OTG-ID", the way this was supposed to work is that devices that only support device mode have a "B" socket while devices that support both modes would have an "AB" socket. Cables would have an A connector ...


2

I thought the ID pin was pin 4 not 5. Pin 5 is ground. [picture showing pin4 as id and pin5 as ground] pinouts From another source with pin 4 as id


1

After much debugging and ordering a 6A power supply I solved it. There are actually two different things going on here. The first is that my USB chargers don't want to deliver much power. My new 6A power supply solved that issue, but my circuit was still only pulling around 400mA. When connected to my bench power supply it pulled 2A, so that wasn't what I ...


3

Take a look at USB Type-C specification. What you are trying to do is a Sink-only UFP, without PD. Look at Table 3-5 and Figure 4-5. In short: Pull down each CCx pin to ground through a distinct 5.1 kΩ resistor, Leave SBUx unconnected, Short DPs, DMs, VBUS and GND pins by group. Do what is specified by the MCU manufacturer for external pullup/downs on DP ...


2

I'm assuming that your board with a microcontroller will take on the role of a USB 2.0 device (as opposed to a host). If so, it needs to wired up like so: Connect all GND contacts with each other Connect all VBUS contacts with each other Connect the D+ and D- pairs with each other (A6 to B6, and A7 to B7) Leave SBU1 and SBU2 unconnected Pull CC1 and CC2 ...


1

The _N typically indicates 'negated' and thereby it is active LOW.


1

USB signals always are bidirectional, and bidirectional switches based on transmission gates are not any more complex or expensive than other kinds, so it is not worth mentioning. Both chips can be used as 1:2 or 2:1 switches. The different names do not matter; the behaviour is the same. You know that these chips work for USB because they are designed for ...


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