Hey guys i would apreciate some help here. My trampa vesc 6 mk5 is cutting out during hard acceleration. Blinks red light, as soon as i let off the throttle it goes away and works properly.
Seams like newer batches of the DRV chips react quite sensitive on a specific part placement next to one pinout. This was not the case before but now it is more sensitive in this area. We recently did some research on how to stabilize these DRVs to 120A and Vedder found out how to re-arrange the components. New batches of the VESC 6 will consider this. For the current batch 80A seams to be a limit on some motors.
@frank, any more info on the sensitivity? Possibly decoupling caps on DVDD/AVDD? I am seeing some of this on custom designed hardware (for industrial motors). As the DRV are currently hard to get, we were able to get some DRV8310Q (Automotive) versions of the chip, and they are quite sensitive, but a batch from Aliexpress seems to work better. Digikey has not stock on until some time next year... From the documentation on the DRV, the only thing that appears to drop the fault line with no error registering via SPI would be DVDD undervoltage.
If you like you can re-position C17 to solve this. Unfortunateley it sits on the lower side and the heat pad needs to be renewed. It is a 6W/mk 0.5mm non conductive pad.
So that is the DVDD cap. Does the original ground trace go directly to AGND then to the power pad? And you are moving it to a digital ground instead? DRV documentation states:
• AVDD and DVDD bypass capacitors should be placed close to their corresponding pins with a low-impedance path to the AGND pin. It is preferable to make this connection on the same layer.
• AGND should be tied to device GND (PowerPAD) through a low impedance trace/copper fill.
Just curious what the actual fix is on newer boards.
It has never been a problem with this layout until the recent batch of DRVs. On the new batches the Caps are placed differently and we can pul 120A without any issue,
Try to lower the Motor Amps below 80A.
Thanks for the tip, do you have any idea whats cousing it ?
Seams like newer batches of the DRV chips react quite sensitive on a specific part placement next to one pinout. This was not the case before but now it is more sensitive in this area. We recently did some research on how to stabilize these DRVs to 120A and Vedder found out how to re-arrange the components. New batches of the VESC 6 will consider this. For the current batch 80A seams to be a limit on some motors.
@frank, any more info on the sensitivity? Possibly decoupling caps on DVDD/AVDD? I am seeing some of this on custom designed hardware (for industrial motors). As the DRV are currently hard to get, we were able to get some DRV8310Q (Automotive) versions of the chip, and they are quite sensitive, but a batch from Aliexpress seems to work better. Digikey has not stock on until some time next year... From the documentation on the DRV, the only thing that appears to drop the fault line with no error registering via SPI would be DVDD undervoltage.
If you like you can re-position C17 to solve this. Unfortunateley it sits on the lower side and the heat pad needs to be renewed. It is a 6W/mk 0.5mm non conductive pad.
So that is the DVDD cap. Does the original ground trace go directly to AGND then to the power pad? And you are moving it to a digital ground instead? DRV documentation states:
• AVDD and DVDD bypass capacitors should be placed close to their corresponding pins with a low-impedance path to the AGND pin. It is preferable to make this connection on the same layer.
• AGND should be tied to device GND (PowerPAD) through a low impedance trace/copper fill.
Just curious what the actual fix is on newer boards.
It has never been a problem with this layout until the recent batch of DRVs. On the new batches the Caps are placed differently and we can pul 120A without any issue,