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3 votes
Accepted

USB 2.0 Full-speed differential impedance

In short, the external resistors are used to match the output impedance of the chip which is too small to the required driver impedance of the wire, Zdrv. It also does not mean that the wire must be ...
Justme's user avatar
  • 149k
3 votes

USB Type C mobile phone charger Design using MPQ4242-AEC1

For battery in automotive systems, the voltages can go higher or lower than the specified voltage. for example, for load dump scenarios the voltage can go upto 87V for a 12V systems. Similarly for ...
shafeeq's user avatar
  • 180
2 votes
Accepted

USB Type C mobile phone charger Design using MPQ4242-AEC1

A 12 V will be coming from my battery. As per my knowledge the battery should be able to provide a current of 3 A or more. Please correct me if I am wrong. At 20V/3A output (I don't know if the chip ...
Rohat Kılıç's user avatar
2 votes

SD/µSD card pins

This socket you've identified is designed for UHS-II or SD Express cards... which, based on your question and the controller you've selected is not something you're planning to support. The following ...
Attie's user avatar
  • 1,895
2 votes

How to use one USB-C port between 2x ESP32-S3 - Switched by toggle switch?

Have you considered using a cheap USB hub IC (like this one)? The USB bus is hub based and will mean that both downstream MCUs will be available to the host simultaneously on different addresses. No ...
AidenDawn's user avatar
1 vote

When/why to use a power source selection switch?

Can you guarantee at 100% that there the battery will always be disconnected when the USB is plugged in? If not, some users will plug both at once (even if you write a warning in big red letters ...
Sandro's user avatar
  • 7,287
1 vote

When/why to use a power source selection switch?

First of all, you can't connect two power supplies together. At least, not without facing the possible consequenes of fried equipment. Second is, it would violate USB specs. Assuming your USB ...
Justme's user avatar
  • 149k
1 vote

Conducted emission test setup for USB powered device with no mains connection

Yes I think it is, you need to test any normal operating modes and if you have a cable you should test it with that. I would talk to the NRTL that you are certifying with because it's going to be up ...
Voltage Spike's user avatar
  • 82.8k
1 vote

USB 3.0 SS lines issue

When making boards, it is important to follow the specifications for the protocols you are trying to transfer. USB 3.0 is a high speed protocol, it samples at a fast rate. You want to avoid stubs and ...
Ferrybig's user avatar
  • 1,154
1 vote

Circuit to handle multiple PSU input options

I think the simplest solution is two or three diodes (like a diode-OR gate)... and then whatever is the highest of the input voltages will go to the >=5V rail and the 3.3V regulator. The 1N5819 is ...
dragoncoder047's user avatar
1 vote
Accepted

Seeking USB-C Female PCB Connector for Razer Kraken X Headphones Adaptation

Usual solution to your problem of adapting a USB-A captive cable (as on many headsets) to a USB-C port is to buy a simple adapter like this one: No modification of any sort is needed.
Ale..chenski's user avatar
  • 40.7k
1 vote

Are there any egregious errors in this design?

Windows recognizes the fact that it is a USB device, but I can't seem to write any configuration data to the chip over SMBus. Initial (power-on) configuration of the IC is determined by CFG_SEL[1:0] ...
Ale..chenski's user avatar
  • 40.7k
1 vote
Accepted

Convert RS232 signal to USB

OK it's a CH340 UART bridge, connect VCC to 5v to power it from USB, I'm assuming it's all UART signals, (not RS232), when it's square pin headers like that it's usually UART. Connect GND to GND ...
Jasen  Слава Україні's user avatar
1 vote

Power delivery controller confusion

That chip is not only a PD controller but it also offers many other things. Quote from data sheet you linked what a PD controller means : "The USB-PD controller provides the physical layer (PHY) ...
Justme's user avatar
  • 149k
1 vote
Accepted

Power delivery controller confusion

... apply a certain frquency pulse to the boost converter to rise it to the desired voltage level. Well, we can't generalise this as "applying a certain frequency pulse" because the ...
Rohat Kılıç's user avatar
1 vote

USB C Power Delivery using below schematic?

First of all, if there is no Power Delivery communication, there is no Power Delivery levels of power available. The system you have drawn is a DFP anf it does indicate to the UFP that it is a DFP ...
Justme's user avatar
  • 149k
1 vote

USB C Power Delivery using below schematic?

No, this might potentially damage your systems, and not work even if they are protected against that damage: The phone will want to negotiate the voltage itself, and you can't simply add another load ...
Marcus Müller's user avatar
1 vote
Accepted

Wiring USB-C connector to micro-USB

You have bought a wrong Type-C plug, a host-simulating plug intended for plugging it into a device, signaling to a device that it can draw the default amount of current. But what you want to do needs ...
Justme's user avatar
  • 149k
1 vote

Wiring USB-C connector to micro-USB

What you are building is a cable assembly fully defined in the Type-C spec. See paragraph 3.5.7 USB Type-C to USB 2.0 Micro-B Cable Assembly on page 84. Aside from connecting VBus, Ground D+ and D- ...
Nipo's user avatar
  • 1,638

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