Part Number: DRV8305
I am using DRV8305 MOSFET driving IC. I am not getting PWM output from this.
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DRV8305: not getting pwm output
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RE: DRV8308: behavior when switching position while moving
Hong,
DRV8308 had some changes from Rev A to Rev B which may cause the Motor stuck. We had a workaround to deal with it.
But, before we work on the Rev B control method, would you read out all the IC top marking letters on your board and EVM?
DRV8308 had some changes from Rev A to Rev B which may cause the Motor stuck. We had a workaround to deal with it.
But, before we work on the Rev B control method, would you read out all the IC top marking letters on your board and EVM?
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RE: DRV8308: behavior when switching position while moving
On your previous question: we pretty much copy the EVM circuit except we control the DRV8308 through FPGA instead of microController as in EVM.
on chip letter: EVM: DRV8308 TI431C A9PL G4
my board: DRV8308 TI 831C ARKG G4
please let us know the workaround and reference on that : we have troubleshot it for quite some time now and really run out of ideas.
thanks,
Hong
on chip letter: EVM: DRV8308 TI431C A9PL G4
my board: DRV8308 TI 831C ARKG G4
please let us know the workaround and reference on that : we have troubleshot it for quite some time now and really run out of ideas.
thanks,
Hong
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RE: DRV8801: Reverse Current Reduction
Hello,
1. This link (www.mawdsleysber.co.uk/.../ ) gives "Common Causes Of Carbon Brush Wear In DC Motors"
a. Brushes being installed incorrectly or the wrong sized brush being fitted
b. Brushes experiencing damage due to electrical underloading or overloading
c. Winding faults
d. Voltage surges to the motor
e. Issues with the commutator – excessive sparking caused by worn brushes
f. Brushes not being shaped to fit arc of commutator
"we found that there was lots of Carbon which gather around the Carbon Brush after running for 1~2 month(normally, the motor can run as long as 3 months" Do you mean the motor could run 3 months with other driver or other control method?
According the above listed carbon brush worn out reasons, we can try to reduce voltage surges to the motor. That is related your 2nd question.
2. Some brushed motors have a small build-in capacitor in paralleling with the motor winding. That can cause a high di/dt event during the winding terminal voltage changes. If we want to reduce this high di/dt, we may need to reduce voltage surges to the motor during the DRV8801 switching. Please add a small inductor or magnetic bead in series with the motor.
Would you verify this idea by adding an inductor in series with the motor to see the current spike change?
1. This link (www.mawdsleysber.co.uk/.../ ) gives "Common Causes Of Carbon Brush Wear In DC Motors"
a. Brushes being installed incorrectly or the wrong sized brush being fitted
b. Brushes experiencing damage due to electrical underloading or overloading
c. Winding faults
d. Voltage surges to the motor
e. Issues with the commutator – excessive sparking caused by worn brushes
f. Brushes not being shaped to fit arc of commutator
"we found that there was lots of Carbon which gather around the Carbon Brush after running for 1~2 month(normally, the motor can run as long as 3 months" Do you mean the motor could run 3 months with other driver or other control method?
According the above listed carbon brush worn out reasons, we can try to reduce voltage surges to the motor. That is related your 2nd question.
2. Some brushed motors have a small build-in capacitor in paralleling with the motor winding. That can cause a high di/dt event during the winding terminal voltage changes. If we want to reduce this high di/dt, we may need to reduce voltage surges to the motor during the DRV8801 switching. Please add a small inductor or magnetic bead in series with the motor.
Would you verify this idea by adding an inductor in series with the motor to see the current spike change?
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RE: DRV2605: Cannot get haptic feedback either with LRA or Piezo
Hi Leon,
Please let us know the results of changing Rext; hopefully this will solve the situation with DRV2700.
Best regards,
-Ivan Salazar
Applications Engineer - Low Power Audio & Actuators
Please let us know the results of changing Rext; hopefully this will solve the situation with DRV2700.
Best regards,
-Ivan Salazar
Applications Engineer - Low Power Audio & Actuators
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DRV2605: Cannot get haptic feedback either with LRA or Piezo
Part Number: DRV2605
Hello,
I am trying to get a haptic feedback either using LRA motor with DRV2605, or using piezo with DRV2605/DRV2700 (based on application report SLOA255).
When using just LRA, the haptic feedback is barely noticeable. However, when the LRA is driven directly from a power supply, the feedback is strong.
When using the DRV2700 with a signal from DRV2605, there is no feedback can be felt. I also notice that the FB pin does not output 1.3V. Thus my PVDD signal is around 10V instead of 65V.
Attached is the schematics of the haptic driver circuit. The selection between Piezo or LRA is done using J1 and J2 jumpers.
LRA motor - 1020-15-003-001 (www.digikey.ca/.../j2rmtd)
Piezo - Z63000Z2910Z 1Z 2 (www.digikey.ca/.../j2rm8v)
I am looking for any possible recommendation.
Thank you.
Regards,
Leon
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RE: DRV8308: behavior when switching position while moving
Hong,
Thank you for your input. Would you send me a private message? So, we can discuss it.
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RE: DRV8308: behavior when switching position while moving
Hello Wang,
I am confused : what do you mean "would you send me an email?". first I don't have your email address. Secondly I don't know what you are expecting me to send. Please guide me on it. And I am really looking forward to the workaround of switching motor direction.
thank,
Hong
I am confused : what do you mean "would you send me an email?". first I don't have your email address. Secondly I don't know what you are expecting me to send. Please guide me on it. And I am really looking forward to the workaround of switching motor direction.
thank,
Hong
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RE: DRV8308: evaluation board
Hello James,
have you got the answer?
thanks,
Hong
have you got the answer?
thanks,
Hong
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RE: DRV8846: DRV8846 use problems
Rock,
Sorry for the delay. I thought it was replied on last Saturday.
1. In general, 250kHz fstep is not for motor motion control because the motor inductor current may not get the setting value when the next step signal is received. Datasheet 8.2.2.1 Stepper Motor Speed gives a equation.
250kHz setting could be used in another scenario: the motor stops at a position A which is different than the initial default 45 degree. After sleep, if customers want to quickly get the previous position A, they can use this 250kHz fstep to quickly get there before enable driver output.
2. AutoTune is what we want for decay mode control. But, DRV8846 offers manually decay mode setting for some customers who want to use their own decay control.
3. Table 6 gives the tBLANK selection according to Torque DAC percentage. In our case: If the input supply is 5V, motor DCR is 14 ohm and 1ohm sense resistor is used. The winding current is 5V/15ohm=333mA. The maximum allowing voltage on the sense resistor is 500mV; maximum VREF is 3.3V. According to the equation (1), it allows us selecting 75% TORQUE to support 333mA IFS and narrow tBLANK range.
4. The item3 just talks about the RxISEN selection. If we use 1ohm sense resistor:
a. it almost use full 500mV range which is good.
b. The worst case the power dissipation on that sense resistor is 111mW when the winding current is at peak current. When motor is rotating, the wind current is sine waveform. So, the average sense resistor power dissipation could be lower than 111mW.
Sorry for the delay. I thought it was replied on last Saturday.
1. In general, 250kHz fstep is not for motor motion control because the motor inductor current may not get the setting value when the next step signal is received. Datasheet 8.2.2.1 Stepper Motor Speed gives a equation.
250kHz setting could be used in another scenario: the motor stops at a position A which is different than the initial default 45 degree. After sleep, if customers want to quickly get the previous position A, they can use this 250kHz fstep to quickly get there before enable driver output.
2. AutoTune is what we want for decay mode control. But, DRV8846 offers manually decay mode setting for some customers who want to use their own decay control.
3. Table 6 gives the tBLANK selection according to Torque DAC percentage. In our case: If the input supply is 5V, motor DCR is 14 ohm and 1ohm sense resistor is used. The winding current is 5V/15ohm=333mA. The maximum allowing voltage on the sense resistor is 500mV; maximum VREF is 3.3V. According to the equation (1), it allows us selecting 75% TORQUE to support 333mA IFS and narrow tBLANK range.
4. The item3 just talks about the RxISEN selection. If we use 1ohm sense resistor:
a. it almost use full 500mV range which is good.
b. The worst case the power dissipation on that sense resistor is 111mW when the winding current is at peak current. When motor is rotating, the wind current is sine waveform. So, the average sense resistor power dissipation could be lower than 111mW.
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DRV8846: DRV8846 use problems
Part Number: DRV8846
Hi!
We have a customer plan to use DRV8846, but they have some questions as below.
Could you please reply these questions? Customer will use fstep=39.024KHz, stepping level = 1/32, rising and falling edges.
1. In datasheet, fstep max = 250KHz.
If fstep = 250KHz, Tsw = 4us, but toff min = 10us. If Tsw < toff, is this OK? Why? Can it result that current can't decrease timely? Because in toff, there will be 2 step pluse(assumption: rising-edge only).
2. How to choose Decay mode?
Customer asked that since we have AutoTune and why we supply other decay modes to them.
3. How to select tBLANK? It means how to select Torque DAC.
4. Attachment is stepper datasheet that customer will use, how to select RxISEN according stepper datasheet?
Appreciate it for your help!
Best Regards,
Rock Su
[View:/cfs-file/__key/communityserver-discussions-components-files/38/SM5_2D00_F20_2D00_VHT7_A000_.pdf:1230:0]
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RE: DRV8308: behavior when switching position while moving
Hong,
When you put cursor on my name, you could see "send a private message" option. Click that, you can send me message. (You are right, not go through email. So, I updated the previous post to use e2e message.)
When you put cursor on my name, you could see "send a private message" option. Click that, you can send me message. (You are right, not go through email. So, I updated the previous post to use e2e message.)
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RE: DRV8308: evaluation board
Hong,
I saw your another post talked about DRV8308 EVM and rev B part also. Let us close this post and discuss it with e2e message to fix your issue.
I saw your another post talked about DRV8308 EVM and rev B part also. Let us close this post and discuss it with e2e message to fix your issue.
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DRV8308: evaluation board
Part Number: DRV8308
Hello,
I would like to make sure that DRV8308 EVM comes with the latest rev b version of DRV8308 before my purchasing of it. could you please confirm it?
thanks,
Hong
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RE: drv10983evm explain this circuit
Deva,
Thanks for the clarification. I've asked the original designers of this circuit to provide feedback on your questions. I'll pass them along as soon as I receive them.
Thanks,
Brian
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RE: I'm looking to drive a low voltage, low amperage motor, and I'm wondering if TI has any applicable nMOS transistors
Thanks Chris.
It is 24 VDC, 2A. Motor speed is 120 RPM
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RE: I'm looking to drive a low voltage, low amperage motor, and I'm wondering if TI has any applicable nMOS transistors
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RE: BOOST-DRV8711: DRV8711 stall check
Darren,
There is an application note to talk about STALL setting.
DRV8711 Quick Spin and Tuning Guide (www.ti.com/.../slva632.pdf ) Page 9 and 10:
The best way to configure internal stall detect is by selecting a desired stall speed (in rpm). Set both SDTHR and VDIV to their minimum values. Next, decrease the motor speed to the desired stall detect speed. Use Equation 10 to determine the necessary stepping frequency:
There is an application note to talk about STALL setting.
DRV8711 Quick Spin and Tuning Guide (www.ti.com/.../slva632.pdf ) Page 9 and 10:
The best way to configure internal stall detect is by selecting a desired stall speed (in rpm). Set both SDTHR and VDIV to their minimum values. Next, decrease the motor speed to the desired stall detect speed. Use Equation 10 to determine the necessary stepping frequency:
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DRV10970: What will happen if VINT is short?
Part Number: DRV10970
Hi team,
My customer will use the DRV10970 in Hall IC mode.
So they will connect the hall input to the VINT.
1. they want to know if the VINT is short by accident(such as connect to GND directly), What will happen?
2. Do we have some protection when the VINT is short?
3. If there is some protection when the VINT is short, how can we recover the chip when the protection is active?
Lacey
Thanks a lot!
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DRV8814: decay modes more questions
Part Number: DRV8814
Hi
I have understood ( from previous discussions ) that some differences between the decay modes are:
1. In fast decay, the current is flowing thru the Rsese resistor while in decaying (excluding dead time when it flows thru the fly wheek diode in the FET).
2. In the slow decay, the current does not flow thru the Rsense resistor at all.
Question:
Are the two statements correct? and if not what is the correct scenario on the decay modes?
if the statements are right should I expect a negative voltage on Rsense when using fast decay?
regards, M. Hooper
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