About the spindle output(U/V/W) in TPIC2060

Hi Tao_2199,

Our experts have been notified and should reply soon.

Tao2199,

I believe the TPIC2050 and TPIC2060A are based on the same design, and their registers are similar. There shouldn't be much of a difference between the two devices. I have a few follow-up questions.

- Is your customer seeing this behavior on multiple systems with the TPIC2060A? I'm wondering if it is just a single device issue.

- Are all the decoupling capacitors on both the TPIC2060A and TPIC2050 systems the same, and do they follow the datasheet recommendation under section 10 "Power Supply Recommendations?"

- Can you please clarify the meaning of the blue trace? It says "12V," but the scope shows 1V/div

- Can you please send me the SPI commands before, during, and after this time for both the TPIC2050 and TPIC2060 systems?

Hello James,

 

Sorry for late reply.

I have confirmed to my customer following.

 

- Is your customer seeing this behavior on multiple systems with the TPIC2060A? I'm wondering if it is just a single device issue.

->(Ans)

They confirmed same phenomenon on other board with other TPIC2060.

 Please refer attached file.

 

- Are all the decoupling capacitors on both the TPIC2060A and TPIC2050 systems the same, and do they follow the datasheet recommendation under section 10 "Power Supply Recommendations?"

->(Ans)

They confirmed that the decoupling capacitor is placed according to the datasheet(section 10).

(It is same as board with TPIC2060.)

 

- Can you please clarify the meaning of the blue trace? It says "12V," but the scope shows 1V/div

->(Ans)

Sorry, they mistook the scaling. They measured with correct scaling again.

 Please refer attached file.

 

- Can you please send me the SPI commands before, during, and after this time for both the TPIC2050 and TPIC2060 systems?

->(Ans)

They confirmed the SPI commands. Please refer attached file.

(Before motor acceleration, At completing CAV control.)

 

Regards,

Tao_2199

 

Confiirmenation_result.xlsx

Tao_2199,

Thank you for your detailed responses. I believe that this is due to one of the functional modes accessible on the TPIC2060 that is not available on the TPIC2050. Can you please have your customer run a test where all the registers for the TPIC2060A are configured the same as the TPIC2050?

James

Hello James,

Thank you for reply.

They confirmed phenomenon with following setting.

1) The configured the same as the TPIC2050 register.

-> It was not improved.  (The phenomenon is happened yet.)

2) Register 0x6B:0x00->0x04

-> It was improved.  (The phenomenon is disappeared.)

Please refer attached file.

They are not sure why it will be improved by changing Register 0x6B data.

(SPM_RCDDIS: Spindle block reverse current detect function: Enable -> Disable)

Could you please tell me the possible route cause?

Regards,

Tao_2199

7077.Confiirmenation_result.xlsx

Hello Tao_2199,

Thank you for providing well-documented data, and great job finding the register setting that causes the operation you are seeing!

I believe that register setting is related to the braking feature of this device. It also helps to reduce the current during deceleration. Do you change the value in the VSPM DAC when you see this occur?

Hello James,

 

Thank you for reply.

They confirmed VSPM_DAC as following .

- Do you change the value in the VSPM DAC when you see this occur?

(Ans.)

-> Yes. At changing timing (Motor acceleration-> CAV control ) ,

SPM is not set the brake but VSPM DAC is almost set as zero in a moment.

Please refer attached file.

 

(As additional information.)

*At other point (SPM Deceleration/ Acceleration),

Same phenomenon is be happened. Please refer attached file.

 

Could you please tell me the mechanism of root cause?

If you need information more, please let me know.

 

Regards,

Tao_2199

6557.Confiirmenation_result.xlsx

Tao_2199,

I believe the phenomenon is a device feature that reduces the reverse current during deceleration. For whatever reason, this feature isn't highlighted in the datasheet for TPIC2060.

I think that if the customer is changing VSPM from a high value to a lower value, the TPIC2060 considers the motor to be decelerating, so it sets all outputs to Hi-Z. During Hi-Z, the BEMF creates a current that dissipates the rotational energy in the body diodes and the parasitic resistance to slow the motor. This should last for about 26 ms, which I believe you said the customer observed.

Is your customer happy with the workaround of setting REG0x6B to 0x04 to eliminate this phenomenon?

Hello James,

 

Thank you for reply.

 

- Is your customer happy with the workaround of setting REG0x6B to 0x04 to eliminate this phenomenon?

(Ans.)

They confirmed this phenomenon(sine curve) on U/V/W signal.

But they say that it seems that there is not any problem (ex. the fluctuation of motor speed)

as far as seen from the outside.

They are not sure whether it has a bad influence on the system in TPIC2060 by setting REG0x6B.

 

(Question)

･REG0x6B is function that it reduces the reverse current during deceleration.

Is there possible that it has bad influence on the system in TPIC2060 by enable this function?

* They are not sure which registers setting is better. (REG0x6B enable or disable.)

 

Could you please give some comment or advice?

 

Regards,

Tao2199