Activity for DeadMouse
| Type | On... | Excerpt | Status | Date |
|---|---|---|---|---|
| Edit | Post #293048 |
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— | 18 days ago |
| Edit | Post #293048 |
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— | 18 days ago |
| Comment | Post #293049 |
V2 (3.3V) comes from a DC-DC that has V3 as input. Non isolated. The top (hat) board and the bottom (main) share I/O pins and 3.3V for the digital circuits that control the mosfets through a header pin connector. (more) |
— | 18 days ago |
| Edit | Post #293048 | Initial revision | — | 19 days ago |
| Question | — |
Ground loss protection I have a hat board that has some high power solid state switches (mosfets). The hat is controlled by the main board. The hat and the main board are connected via pin headers, like an arduino. The hat board contains some connectors for the power and also the outputs. My main concern is... (more) |
— | 19 days ago |
| Edit | Post #293008 |
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— | 25 days ago |
| Edit | Post #293008 |
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— | 25 days ago |
| Edit | Post #293008 | Initial revision | — | 25 days ago |
| Question | — |
Photodiode transimpedance amplifier with single supply I have a photodiode and I want to connect it to an ADC to read the ambient light. For the context, non linearity is not an issue as I'm interested in knowing the amount of light in 3-4 levels. The sensor itself pays a huge role on it anyway. I don't have a part number of any details about the... (more) |
— | 25 days ago |
| Comment | Post #292080 |
I'm designing a system that will be plugged into a car's CAN bus. (more) |
— | 5 months ago |
| Comment | Post #292089 |
I tried polling the error counters. I didn't see anything increasing. All that while PIC was not connected with another node. (more) |
— | 5 months ago |
| Comment | Post #292089 |
I think it doesn't give up and it is constantly trying to transmit the message. That was the real problem. I need to implement a custom timeout but I have no idea how much should that timeout be. (more) |
— | 5 months ago |
| Edit | Post #292080 |
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— | 5 months ago |
| Edit | Post #292080 | Initial revision | — | 5 months ago |
| Question | — |
CAN bus open circuit detection I have a PIC18 and I'm trying to detect whether it is connected on the CAN bus or not. When the PIC is not connected on the bus, and I load the transmit buffers, after setting the TXREQ flag. The transmission does not start. This is also mentioned in the datasheet: > Setting the TXREQ bit d... (more) |
— | 5 months ago |
| Edit | Post #291983 |
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— | 5 months ago |
| Edit | Post #291983 |
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— | 5 months ago |
| Edit | Post #291983 |
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— | 5 months ago |
| Edit | Post #291983 | Initial revision | — | 5 months ago |
| Question | — |
How to operate a chip very close to its absolute maximum voltage? I want to operate a BLE chip at very close to its absolute maximum voltage. The chip is nRF52810 This is intended for a battery powered device and I want to use a 3.6V non-rechargable battery directly wired to the chip. However the datasheet in page 409 mentions: Imagealttext that its ab... (more) |
— | 5 months ago |
| Edit | Post #291934 |
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— | 6 months ago |
| Edit | Post #291934 | Initial revision | — | 6 months ago |
| Question | — |
Are LDOs more efficient than switching regulators in very low currents? I'm looking for a power supply to power up the VCORE of an mcu. The chip is an STM32 microcontroller (LQFP) and the maximum current it will draw is no more than 150mA. The input will be 3V-5V max and the output 1.2V I usually go with LDO even for the whole chip power but in this case I nee... (more) |
— | 6 months ago |
| Comment | Post #291038 |
You are right about R18. I think it should be lower at around 1K.
Regarding the 3.2mA it is fine. I have tested that already and it worked without issues. I could also make it a bigger value.
Another issue is how to merge the TX and RX lines so I can have only one but also maintain the protecti... (more) |
— | 9 months ago |
| Edit | Post #291027 |
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— | 9 months ago |
| Edit | Post #291027 |
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— | 9 months ago |
| Edit | Post #291027 | Initial revision | — | 9 months ago |
| Question | — |
1-wire interface overvoltage protection I'm designing a robust 1-wire output for an IoT board. The interface should be able to withstand high voltage. Mainly the same voltage level as the board power supply. That's 12V to 36V DC. The protection is intended for the board only, not the devices connected to it. Consider the protect... (more) |
— | 9 months ago |
| Comment | Post #288784 |
Would you mind to elaborate the reasons why you would not add a ground pour on top/bottom layers? (more) |
— | over 1 year ago |
| Edit | Post #288763 |
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— | over 1 year ago |
| Edit | Post #288763 |
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— | over 1 year ago |
| Comment | Post #288784 |
I posted some pictures that show how bypass capacitors are placed around the chip. Notice that some of them cannot have direct connection to their relative ground pins of the chip cause sometimes the ground pins are not physically close to the power pins and other gpio pins there are in between them.... (more) |
— | over 1 year ago |
| Edit | Post #288763 |
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— | over 1 year ago |
| Comment | Post #288784 |
Regarding bypass capacitors you mean to avoid connecting them directly to the internal ground plane using a via?
Do you mean that they should be connected to the ground pins directly using traces or local planes and connect all of it together to the internal ground plane? (more) |
— | over 1 year ago |
| Comment | Post #288784 |
I'm not sure I understand your point about the ground plane being a center-fed patch antenna.
I didn't mean there's only one via that connects every ground from the top layer to the internal ground plane.
I have placed vias close to every pad that is connected to ground and using a trace or a ... (more) |
— | over 1 year ago |
| Edit | Post #288763 |
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— | over 1 year ago |
| Edit | Post #288763 |
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— | over 1 year ago |
| Edit | Post #288763 | Initial revision | — | over 1 year ago |
| Question | — |
Ground pour on outer layers on 4-layer PCB I'm designing a board that contains a cortex-M4 mcu working at 120MHz, and an ethernet bus with a wiznet chip that communicates with SPI. The ethernet chip gives me a phy output that goes directly to a connector with internal magnetics. All circuits are powered by a DC to DC buck converter.... (more) |
— | over 1 year ago |
| Comment | Post #288515 |
Why do you prefer a voltage divider over a zener diode? (more) |
— | over 1 year ago |
| Comment | Post #288515 |
NPN version.
Thanks, Olin.
I concluded you like more the NPN version versus the MOSFET version.
Regarding your last schematic.
R1-R2 form a voltage divider and the threshold is around 11V at the input. At this voltage, the Vbe will be around 0.7V and it is enough for the BJT to star... (more) |
— | over 1 year ago |
| Edit | Post #288504 |
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— | over 1 year ago |
| Edit | Post #288504 |
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— | over 1 year ago |
| Edit | Post #288504 |
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— | over 1 year ago |
| Edit | Post #288504 |
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— | over 1 year ago |
| Edit | Post #288504 |
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— | over 1 year ago |
| Edit | Post #288504 |
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— | over 1 year ago |
| Edit | Post #288504 |
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— | over 1 year ago |
| Edit | Post #288504 |
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— | over 1 year ago |
| Edit | Post #288504 |
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— | over 1 year ago |