Activity for DeadMouse
| Type | On... | Excerpt | Status | Date |
|---|---|---|---|---|
| Comment | Post #292080 |
I'm designing a system that will be plugged into a car's CAN bus. (more) |
— | 4 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) |
— | 4 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) |
— | 4 months ago |
| Edit | Post #292080 |
Post edited: |
— | 4 months ago |
| Edit | Post #292080 | Initial revision | — | 4 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) |
— | 4 months ago |
| Edit | Post #291983 |
Post edited: |
— | 4 months ago |
| Edit | Post #291983 |
Post edited: |
— | 4 months ago |
| Edit | Post #291983 |
Post edited: |
— | 4 months ago |
| Edit | Post #291983 | Initial revision | — | 4 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) |
— | 4 months ago |
| Edit | Post #291934 |
Post edited: |
— | 4 months ago |
| Edit | Post #291934 | Initial revision | — | 4 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) |
— | 4 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) |
— | 8 months ago |
| Edit | Post #291027 |
Post edited: |
— | 8 months ago |
| Edit | Post #291027 |
Post edited: |
— | 8 months ago |
| Edit | Post #291027 | Initial revision | — | 8 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) |
— | 8 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 |
Post edited: |
— | over 1 year ago |
| Edit | Post #288763 |
Post edited: |
— | 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 |
Post edited: |
— | 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 |
Post edited: |
— | over 1 year ago |
| Edit | Post #288763 |
Post edited: |
— | 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 |
Post edited: |
— | over 1 year ago |
| Edit | Post #288504 |
Post edited: |
— | over 1 year ago |
| Edit | Post #288504 |
Post edited: |
— | over 1 year ago |
| Edit | Post #288504 |
Post edited: |
— | over 1 year ago |
| Edit | Post #288504 |
Post edited: |
— | over 1 year ago |
| Edit | Post #288504 |
Post edited: |
— | over 1 year ago |
| Edit | Post #288504 |
Post edited: |
— | over 1 year ago |
| Edit | Post #288504 |
Post edited: |
— | over 1 year ago |
| Edit | Post #288504 |
Post edited: |
— | over 1 year ago |
| Edit | Post #288504 |
Post edited: |
— | over 1 year ago |
| Edit | Post #288504 | Initial revision | — | over 1 year ago |
| Question | — |
Sensing 3 states in a single mcu pin using firmware I want to sense 3 different states in the same mcu pin (GND, Hi-Z and PWR). PWR is typical +24V but I would like to have a wide margin from +17V to +40V just to be safe. The values can change but the typical will still be +24V I need 32 different (physical) inputs. I designed the following c... (more) |
— | over 1 year ago |
| Comment | Post #288474 |
Thanks! That's helpful (more) |
— | over 1 year ago |
| Edit | Post #288440 |
Post edited: |
— | over 1 year ago |
| Edit | Post #288440 |
Post edited: |
— | over 1 year ago |
| Edit | Post #288440 |
Post edited: |
— | over 1 year ago |
| Comment | Post #288440 |
Also, a simple inversion won't do the trick. I added a truth table that shows the output with 3 differnt types of input for each option.
For example, if you just put a NOT gate on Option 1, you will not get Option 2. (more) |
— | over 1 year ago |
| Edit | Post #288440 |
Post edited: |
— | over 1 year ago |