DRV8305: Using DRV83055/DRV83053 like DRV8305N

Hello Ray,

Thanks for posting to the forum. Which device did the customer try as a replacement on their board? On the customers board what is the reference voltage connected to the VREG/VREF pin of the DRV8305N?

The reason I ask because the if the customer decides to use DRV83055 or DRV83053, as mentioned they have an LDO that produce 5V and 3.3V respectively, the important thing to note is that this LDO voltage is also used as the reference voltage (Vref) for the current sense amplifier output bias. If there is an external voltage coming from another source while VREG is trying to regulate a 3.3V or 5V output this could be the source of the problem. There are safety mechanisms in place on the device that occur when VREG is above or below a set threshold voltage on Vreg. I have attached a section of the datasheet section 7.3.9.4:

If the customer has a way of modifying the board to connect VREG to ground and add the 1uF capacitor that is recommended then it is possible that they might be able to replace this without any issues. But this fault is the reason why I do not think the motor cannot be driven with their current setup. The undervoltage monitor can be disabled on the device but I would not recommend this until the concerns mentioned are addressed.

Best,

Isaac

Hi Isaac,

Good Day. Please see below another latest query of our customer to your response. Thank you very much.

Can you please provide us more detail on failure? Which part is over heating ?
Please do the followings
When the speed is increased to 60 rpm, “OL” or “OH” is displayed and the motor does not work.
The U1 temperature about 50 degrees.
1. Please check the out put of 3.3 V regulator
The output voltage is 4.97V before programming. And after programming is 3.3V.
And then test the unit, as described above.
2. Please check the voltage on Pin 48 and Pin 13 of U1 also across C8 Capacitor. Let me know the value. If it is over 3.3 V please try the next step in one board.
It is 3.3V.
3. In one board please try to disconnect pin 48 of U1 either by breaking the pin leg or disconnecting the track to C8 and observe if the problem is gone or not. Also try by removing R1
Lift pin 48 of U1, motor is “ ka ka …” and then stop a few seconds. Remove R1, motor does not work.
Replaced DRV83055 with DRV8305N for re-testing about 6 pcs , motor work properly.

Please note U1 is motor driver IC. The issue we faced (tested by the PCB manufacturer) is that the IC gets over heater and the motor does not spin.( production boards programming test is FAILED , after research we found the root cause of the failure[over-heated ] that could due to component U1)

we already have pin 48 connected to GND with a 1uF capacitor added to it. When we replaced with DRV83055 and DRV83053, it is the same design and we faced the above issues.

Best Regards,

Ray Vincent

Hi Isaac,

Customer opted for DRV8305NE (grade 0) simply because DRV8305NPHP went out of stock first. we are ok with either.

Best Regards,

Ray Vincent

Hey Ray,

Okay, that's good to hear just wanted to make sure the small details were not being overlooked, so thanks for clearing that up. Still waiting on the customers schematic to see if we can identify the source of the problem.

Best,

Isaac

Hi Isaac,

Good Day. I have a question. The manager of the customer has agreed to share the schematics on TI signing the confidentiality agreement. Customer wants to know if TI will sign the document so that he can share the schematics. Thank you very much.

Best Regards,

Ray Vincent

Hey Ray,

Thanks for the update here. Have you tried to get the customer to sign an NDA with TI?

Best

Hi Ray,

Are there additional questions on this thread?

Thanks,

Matt

Hi Ray,

I'm going to go ahead and close this thread. If you have further questions, please click the "Ask a related question" button.

Thanks,

Matt