Hi Rick-san,
How is the progress about this?
Best regards,
Shimizu
How is the progress about this?
Best regards,
Shimizu
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RE: DRV8813: UVLO function at low VM voltage
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DRV8813: UVLO function at low VM voltage
Part Number: DRV8813
Hi,
When VM voltage is under UVLO voltage, it is guaranteed that circuitry in the device is disabled completely and internal logic resets by internal fail-safe circuit.
My customer wants to know if UVLO function works well at low VM voltage for example VM=2V. This is power up situation.
Best regards,
Shimizu
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RE: DRV8313: DRV8313 not working
Hi Steven,
The figure shown in the datasheet is for a typical three phase motor configuration without current limit.
To start debugging, please lower the current limit of you power supply to the milliamp range and see if you power supply is still dropping. This will avoid damaging more parts and can give you a clue if there is a short elsewhere on your design.
If you are able to power up your device at lower voltage and current then please monitor the nFAULT, and VCP pin when the device is being enabled.
Also, have you considered start evaluating with our DRV8313 EVM? This evaluation module comes with a downloadable GUI for simpler operation. You could start there and then adjust as your design requires.
Thank you.
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DRV8313: DRV8313 not working
Part Number: DRV8313
Hi,
I have connected DRV8313 exactly as in the data sheet 8.2.1 figure 13.
as soon as turning power supply the current limiter of the power supply turns on (limited to 2A)
then the chip seems to be damaged. Some pins that were not shorted to each other are now shorted to each other
1) prototyping with SSOP28 to DIP expansion board then onto breadboard. The soldering should be fine i went through numerous boards and each time i more than triple check every solder connection using multimeter
2) using 5V arduino as microprocessor but the datasheet section 6.3 says the Vin can be max 5.5V
3) using leds with 220R's as load
Please help!! have already spent many days, tried different schematics and went through many, many chips :(
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RE: Sensored Brushless motor drives
Hi Marco,
Check out our E-bike app note and our page for E-scooter reference designs. Recently, a TI employee worked on a personal project building a scooter with our MSP430F5529 and DRV8302H. I think these are good places to start because they are similar applications. Using a BLDC motor with integrated sensors is probably the easiest way to get started, but if you are interested in going sensorless, we have an application note for that too.
Because you require large currents, I recommend looking at our Brushless DC Gate Drivers portfolio of parts. Particularly DRV8305, DRV8320, and DRV8323 may be the most interesting solutions for your project. Also check out our Power MOSFET and Motor Driver MOSFET portfolios when you need to size FETs.
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RE: DRV8838: Control Method
Hi Yuga,
I made an incorrect interpretation of the PH-EN pins of the DRV8838. See modified answer above. You can drive by making the EN pin have PWM input.
I made an incorrect interpretation of the PH-EN pins of the DRV8838. See modified answer above. You can drive by making the EN pin have PWM input.
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RE: DRV8833: Large current spike at startup
Hi Roy,
Do you have any capacitors on the output?
Usually, this spike current is inrush current. When startup, a high voltage will soon be applied on the capacitor, which cause the inrush current (I=C*dV/dt).
Thanks.
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DRV8833: Large current spike at startup
Part Number: DRV8833
Hi there,
My customer observed a large current spike at motor startup. Please refer to the waveform below. (Measured at AOUT1)
Please also find the schematic attached.
Could you please give us some hint to figure out the cause?
Thanks!
Best regards,
Roy Hsu
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RE: DRV10975: What is scope time scale for PWM voltage high level?
Kaine,
The input goes to a Schmitt trigger. As soon as the DRV10975 sees a voltage level that corresponds to a high the internal bit will be set high. The voltage that a high occurs is likely lower than 2.2V (a 2.2 guarantees a high but should trigger at a lower voltage). The only issue I see with a slow rise time is that you may get more variability in the duty cycle applied.
Thanks,
Brian
The input goes to a Schmitt trigger. As soon as the DRV10975 sees a voltage level that corresponds to a high the internal bit will be set high. The voltage that a high occurs is likely lower than 2.2V (a 2.2 guarantees a high but should trigger at a lower voltage). The only issue I see with a slow rise time is that you may get more variability in the duty cycle applied.
Thanks,
Brian
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RE: DRV8839: We are checking the performance between DRV8839 and DRV8837.
Hi Lian Wu,
I revised my answer:
What is the end application for this questionnaire? What is your operating voltage range?
See answers below:
1. We do not recommend you spin two motors with the DRV8837. Do you mean if the DRV8839 has one braking mode when driving one motor? When driving two motors, there is only one brake mode for each motor connected (the respective motor's INx PWM is low).
The PWMs are independent of each other when driving two motors. So, one motor can brake while the other coasts, brakes, or moves forward.
2. We do not have these diagrams.
3. I checked this out. There should not be a difference in the driving specs between driving one motor or two motors.
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DRV8839: We are checking the performance between DRV8839 and DRV8837.
Part Number: DRV8839
Dears:
We are checking the performance between DRV8839 and DRV8837.
Could you give some advice about the below questions:
1. DRV8837 has two braking mode when it controls two motors, and do DRV8839 have braking mode?
Do DRV8839 happen the phenomenon of mixed braking mode if DRV8839 is driving two motors at the same time (the PWM of the two motors is independent and independent).
2. Is there any diagrams about Forward Direction and Reverse of 50% ,20% Duty Cycle?
3. Is the different between DRV8839 controlling one Motor and DRV8839 controlling two Motors from the Motors' power, response time, braking mode etc?
Thanks a lot!
Best regards
Luck Wu
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RE: DRV8881: Driving a heater module
Hi Rick,
The information I'm working with is a bit second-hand and was only documented in memory. I have enough confidence in the tester, that the setup was configured appropriately to not actually exceed the designed current limit. Nonetheless, I'll be checking back on those specifics you ask, and also try to replicate the test on my side.
In the meantime, are you aware of any precedent for driving resistive loads on this part or others in its family?
The information I'm working with is a bit second-hand and was only documented in memory. I have enough confidence in the tester, that the setup was configured appropriately to not actually exceed the designed current limit. Nonetheless, I'll be checking back on those specifics you ask, and also try to replicate the test on my side.
In the meantime, are you aware of any precedent for driving resistive loads on this part or others in its family?
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RE: DRV8881: Driving a heater module
Hi TJ,
Others in the family have driven resistive loads. Typically it is not a problem as long as the current does not exceed the chopping level. If the current exceeds the chopping level, the outputs will typically turn on for the blanking time (900ns to 1.8us) and then immediately enter current regulation.
Others in the family have driven resistive loads. Typically it is not a problem as long as the current does not exceed the chopping level. If the current exceeds the chopping level, the outputs will typically turn on for the blanking time (900ns to 1.8us) and then immediately enter current regulation.
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RE: Sensored Brushless motor drives
Thanks James!!!
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Sensored Brushless motor drives
Hello!!
I need to develop a E-skate board drive solution using BLDC sensored motors.
Motors: 50A / 36V each (two motors to drive)
I never used ST solutions before, so I need some help to get started.
Is it necessary to use feedback control for such application?
What TI solution is indicated?
Regards,
Marco
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RE: DRV8821: Over-Current Threshold
Hi Rick,
The motor speed is increasing for the first 1.5s of startup The initial step rate is 288Hz (36Hz motor winding) climbing to 3,200Hz (400Hz motor winding). I attached a picture with a table of frequency vs. time. I believe that we are driving the motor beyond its capability. At 400Hz the current is not able to ramp from -1.5A to + 1.5A given a presumed winding inductance of 10.6mH. I surmise that the DRV8821 compensates for this overdrive by adjusting the step timing, but perhaps you can better answer how the DRV8821 would respond to this. The winding current waveform changes as the maximum frequency is approached. There is no longer a step in current and the current is ramping at the maximum to reach the required regulation point. By increasing the value of the sense resistor, the controller is able to meet the higher frequency operation and so the current does not step down with increasing frequency.
I think this answers my question. Let me know if you have any other comments, especially regarding DRV8821 operation at higher frequency than the motor is capable of responding to.
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DRV8821: Over-Current Threshold
Part Number: DRV8821
I'm inheriting a card design using the DRV8821 motor driver to open and close a door. The design delivers 1.5A per winding which goes right up against the 1.5A peak threshold and occasionally trips the OCP. I guess this is no surprise, but the range of current limit is 1.5A to 4.5A, so I would not expect to see a trip typically. I have since increased the sense resistor from 0.28-Ohms to 0.36-Ohms and that has fixed the OCP trip. However, under the original design i'm seeing a dip in the winding current that I would like an explanation. The initial programmed current is correct, but then after ~1s, the current ramps down to a lower level. What in the DRV8821 is dropping the current? Some pictures and schematics are attached.
Note that the following picture monitors the motor winding currents with current probes as this was an easier measurement to make.
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RE: DRV8813: UVLO function at low VM voltage
Hi Shimizu-san,
The device appears to work properly at low VM.
The device appears to work properly at low VM.
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RE: DRV8881: Driving a heater module
Hi Rick,
Apparently my trust in the knowledge of others has been misplaced. I managed to dig out an evaluation board, and it appears it can drive resistive heaters without issue after all.
Apparently my trust in the knowledge of others has been misplaced. I managed to dig out an evaluation board, and it appears it can drive resistive heaters without issue after all.
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RE: CSD88539ND: About EAR
Dear Chris ,
Thank you for your reply.
I want to tell my customers immediately.
Could you tell us more?
· Do you have a plan to develop a dual type with higher pressure rating?
(It is even better if it corresponds to 5 V logic drive.)
· Are there any plans to develop higher voltage products with a single channel compatible with 5 V logic?
My customers are using 100Kpcs / month for other 60V withstand voltage products (other companies present avalanche (EAR)).
I would like to present customers with EAR with CSD 88539 or to introduce FET with higher breakdown voltage.
If there is new product information, would you please teach me?
Best regards,
Mayumi
Thank you for your reply.
I want to tell my customers immediately.
Could you tell us more?
· Do you have a plan to develop a dual type with higher pressure rating?
(It is even better if it corresponds to 5 V logic drive.)
· Are there any plans to develop higher voltage products with a single channel compatible with 5 V logic?
My customers are using 100Kpcs / month for other 60V withstand voltage products (other companies present avalanche (EAR)).
I would like to present customers with EAR with CSD 88539 or to introduce FET with higher breakdown voltage.
If there is new product information, would you please teach me?
Best regards,
Mayumi
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