DRV8323: DRV8323 and DRV8523

Hi Oliver,

Would you mind telling me what problem you were facing with the DRV8323S and what your nominal battery voltage is?

Thank you,

Joshua

Hello Joshua,

Battery voltage ist 48VDC (so less than 65V from the datasheet)

problems are: 

Motordiver will be destroyed (shoot in the housing)

400 to 500 pieces of the product where we are using this driver  are in the market.

Currently we are getting 10 to 20 broken pieces per month, costs for aftersales are terrible high and image problems are massiv.

regards Oliver

Hi Oliver,

To make sure that the issue that is occurring with the DRV8323 will not cause a problem for the DRV8353, would you mind answering the following questions?

1. Could you provide more information on what you mean by "shoot in the housing"?
2. Did the DRV8323 experience voltage spikes on the VM pin that exceeded 65 V?

Thank you,

Joshua

Joshua,

a) "shoot in the housing" means that after damage  there is a hole in the plastic housing of the IC

b) We did not see big spikes on the 48V power lines. The amounts of failures become less, if the battery is connected. So the battery (just 42V) is reducing spikes, because normaly the electric motor is supplied by a power supply unit with 48VDC. So both supplys are possible for the electric motor..

regards Oliver

Hi Oliver,

1. When in the motor operation does the damage occur, when being hand spun, starting stopping?
2. Could you provide me an image of the damage done to the IC?
3. Would you mind providing your schematic?

Thank you,

Joshua

Joshua,

a) The motordriver will break mostly at the start of the motor, even if we tested it in the same application, same software over days before - without damages.

b) i did not find a picture where you can see the damage, because very often you can see the damages just with a magnifying glass. it is just a small hole in the chip, sometimes a small break of the casing.

c) here is the part of the schematic with the driver

regards Oliver

Hi Oliver,

I have checked and there is no easy solution to changing a design from using the DRV8323S to a DRV8353S. You will have to redo the schematic and the layout of your PCB based on the requirements of the DRV8353 as outlined in it's datasheet.

If you would like for me to help you solve the problem you are having with the DRV8323, can you provide your IDrive settings and a capture of GLA, GHA, SHX, and SHX?

Could you resend the schematic? It is very small and I am unable to read it.

Thank you,

Joshua

Hello Joshua, 

currently we are changing the layout, so that we can put on the improved version of the motor driver.

Here is the schematic again, i hope you can read it now.

Schaltplan_Motortreiber.pdf

regards Oliver

Hi Oliver,

Thank you for re-sending the schematic, I can read it now.

If you require any further assistance please let me know.

Best regards,

Joshua 

Hallo Joshua, 

did you checked my schematic, did you see some failures why the motordriver will be break permanently ?

Here is also a foto of the broken motor driver (shoot in the case), maybe this will also help ?

here is the photo of the broken driver (i try it again)

Hi Oliver,

From the schematic I did not see any issue.

Could you tell me the part number of the MOSFETs you are using (I did not see them in the schematic) and the IDRIVE setting you were using?

Thank you,

Joshua

Hello Jushua, 

As FET we are using: SUM 70060E

Here are the requested parameters:

with...

Gate capacität = 13,2nC

Risetime = 100…300ns

Falltime = 50…150ns

following values are calculated:

i_drivep values from 44mA to 132mA

i_driven values from 88mA to 264mA

IDRIVE  set value

P-LS       120 mA

P-HS      120 mA

N-LS      240 mA

N-HS     240 mA

Hi Oliver,

Thank you for the detailed information and picture of the broken chip.

Could you send a capture of the GHx, SHx, GLx, and SLx waveforms when starting the motor?

Thank you,

Joshua