Hi Shimizu,
Our expert will be noticed and get back to you later.
Best regards,
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RE: DRV8432 About application diagram example in datasheet
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DRV8432 About application diagram example in datasheet
Hi,
Could you let me know the mean of 1ohm resistor at GND pin, please?
Best regards,
Shimizu
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RE: DRV8432 Over current protection deglitch time
Hi Shimizu,
The 250ns is just the deglitch time, similar to the Tblanking time we said in other DRV8x devices.
Best regards,
The 250ns is just the deglitch time, similar to the Tblanking time we said in other DRV8x devices.
Best regards,
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DRV8432 Over current protection deglitch time
Hi,
Could you let me know over current protection deglitch time, please?
There is overcurrent response time (250ns) in datasheet.
But I think that this is time from short condition to Hi-Z ofFET.
In another way, this is time after OC detection.
Best regards,
Shimizu
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DRV8302 Fault pin always zero
Dear Friends,
I have used DRV8302, as an MOSFET Driver, in my design for BLDC Motor Control Board.
I have a problem, DRV8302 Fault pin always zero. can you give me some advice please??
[View:/cfs-file/__key/communityserver-discussions-components-files/38/MC_5F00_001-_2D00_-Schematic.pdf:1230:0]
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RE: Isolating two DRV8711 for redundancy
Hi Nathan,
Can you provide a little more information? When one board is back feeding VM through the body diodes of the power FETs, what problem(s) are you experiencing?
We will investigate and reply soon.
Can you provide a little more information? When one board is back feeding VM through the body diodes of the power FETs, what problem(s) are you experiencing?
We will investigate and reply soon.
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RE: Isolating two DRV8711 for redundancy
The node connected to VM is also used as the input voltage to lower voltage power supplies, which try to turn on, which in turn try to turn on other chips that they power. The unpowered board becomes partially powered which interferes with the operation of the intentionally powered board since there are several redundant circuits like this one. Outputs are fighting with each other, dogs and cats living together, mass hysteria.
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RE: Adapting the DRV8305N BoosterPack Eval Module for low-speed and with Hall sensors
the hall sensors for motor commutation are all the same essentially
you can see an example in controlSUITE
C:\ti\controlSUITE\development_kits\DRV8312-C2-KIT_v128\BLDC_Sensored
if you are wanting to use MotorWare InstaSPIN-FOC we don't currently support hall sensors as this solution is sensorless. However, in the next version of MotorWare we will show a project (on DRV8301-69M-KIT) which uses hall sensors for initial start-up and then transitions to sensorless.
you can see an example in controlSUITE
C:\ti\controlSUITE\development_kits\DRV8312-C2-KIT_v128\BLDC_Sensored
if you are wanting to use MotorWare InstaSPIN-FOC we don't currently support hall sensors as this solution is sensorless. However, in the next version of MotorWare we will show a project (on DRV8301-69M-KIT) which uses hall sensors for initial start-up and then transitions to sensorless.
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Adapting the DRV8305N BoosterPack Eval Module for low-speed and with Hall sensors
Folks,
I would like to implement a low-cost BLDC motor controller for mechatronics/robotics applications that combines the capabilities of the DRV8305N BoosterPack Eval Module with low-speed (down to zero) operation, single-step control (as with stepper motors) and force feedback.
I'm anticipating that I can start with the existing DRV8305N BoosterPack design and make the following mods:
- The same or different FETs (for smaller motors).
- Use of Hall effect sensors and the appropriate changes (simplification?) of the motor control firmware.
- Use of stepper motor open-loop techniques, with MCU direct PWM control of the FETs for low-speed and single (micro?) stepping of the BLDC motor.
Please advise with regard to:
- Any special cautions with regard to scaling the FETs, protection circuits, etc., for a range of smaller motors?
- How to modify the firmware for direct Hall-effect sensor use? Differing Hall-effect sensor setups?
- If I successfully accomplish #2, can I get down to single-step operation without transitioning to stepper-motor mode? If not, any advice on how to implement this mode and integrate it with high-speed operation?
The goal is to provide a scalable open-source design for a range of motor sizes for educational robotics applications.
Thanks,
Mike
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RE: Any TO-220 MOSFET(Max Vds >60V Id>60A ) recommended for DRV8301?
Hi Frank,
Can you confirm the gate drive average current is below 30mA RMS?
Please refer to section 8.2.2.1 Gate Drive Average Current Load of the datasheet for the equation?
Can you confirm the gate drive average current is below 30mA RMS?
Please refer to section 8.2.2.1 Gate Drive Average Current Load of the datasheet for the equation?
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RE: DRV8711 high temperature
Hi Thorsten,
We will investigate and reply soon.
While waiting there are a couple of documents to review in case you missed them. They are listed at the end of the datasheet:
DRV8711 Decay Mode Setting Optimization, SLVA637
DRV8711 Quick Spin and Tuning Guide, SLVA632
Please take a look at your current waveforms. You may find that the decay setting is not optimized for your motor/system voltage combination?
We will investigate and reply soon.
While waiting there are a couple of documents to review in case you missed them. They are listed at the end of the datasheet:
DRV8711 Decay Mode Setting Optimization, SLVA637
DRV8711 Quick Spin and Tuning Guide, SLVA632
Please take a look at your current waveforms. You may find that the decay setting is not optimized for your motor/system voltage combination?
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DRV8711 high temperature
I'm using the DRV8711 with IRLR2905Z Mosfets at 42V/4,0Arms. The board dimensions are 71*77mm, 4 layer using large GND copper planes.
After adding series resistors to the lowside FETs the boards work OK even at high voltage. But the power losses are quite high compared to the BOOST_DRV8711 evaluation board. I measured >93°C on top of the DRV8711 with a temperature measuring sticker, board temperature reaches 72°C.
Comparing the FET parameters, they look similar. The only difference (appart from the package) is the higher Gate charge for the IRLR2905 which is typical 23nC compared to 14nC for the FETs on the BOOST_DRV. I tried to increase both IDRIVEN (91=200mA) and IDRIVEP (10=150mA), but that doesn't make any difference.
Other parameters:
R(sense)=0,04R
R(DS,on)=11,0mR
TORQUE=105, ISGAIN=00 (=factor 5), should result in 4,0Arms
Stepmode is set to 1/16 microstep. All other values set to default.
Can you give me a hint were / what to measure to see if the MOSFET timing is OK? I suspect a short time short-circuit between low and high side during transition from high to low or vice a versa.
And how do I select the proper Rise-Time? Maybe the default gate drive times are to fast for these FETs? PWM frequency is now 34kHz, that seems OK to me.
I did a similar design some years ago with the obsolete A3986 on a 2-layer board, using IRLR024N (75mR) and had no trouble with high power losses. So I think the FETs themself shouldn't be the problem here?!
With kind regards,
Thorsten Ostermann
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RE: DRV8302 Fault pin always zero
Hi Umit,
The schematic appears to be good.
Please measure and report the voltages of the following pins when nFAULT is low:
1) PVDD
2) GVDD
3) AVDD
4) DVDD
5) EN_GATE
6) M_PWM
7) INL_x and INH_x
8) BST_x
9) GL_x and GH_x
The schematic appears to be good.
Please measure and report the voltages of the following pins when nFAULT is low:
1) PVDD
2) GVDD
3) AVDD
4) DVDD
5) EN_GATE
6) M_PWM
7) INL_x and INH_x
8) BST_x
9) GL_x and GH_x
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RE: Isolating two DRV8711 for redundancy
Hi Nathan,
Thanks for the clarification. If the control logic remains unpowered, would that solve the problem?
If so, your main supply on one board could be split into two rails. One rail would power the control logic and the second rail would power the motor. The second rail would be behind a FET that is switched on when the control logic is powered. The control logic would then generate a signal to turn on the FET.
There may be other problems to find.
Thanks for the clarification. If the control logic remains unpowered, would that solve the problem?
If so, your main supply on one board could be split into two rails. One rail would power the control logic and the second rail would power the motor. The second rail would be behind a FET that is switched on when the control logic is powered. The control logic would then generate a signal to turn on the FET.
There may be other problems to find.
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Isolating two DRV8711 for redundancy
I am working on a design that requires redundant motor driver circuits. One circuit will be energized (driving a stepper motor with 24V) while the other is not. This second circuit is located on a second circuit board which is not powered. However, both circuits are connected to the motor drive lines (AOUT1, AOUT2, BOUT1, BOUT2). Because of the clamping diodes on these pins of the DRV8711, the motor drive signals from the powered circuit are back-feeding into the power nodes of the unpowered circuit and causing problems. Would it be possible to put a buffer op-amp (or two in parallel) on each of these lines to help isolate them? The op-amps of the unpowered board would be unpowered and therefore not pass the undesired signal to the unpowered DRV8711, but the op-amps on the powered board would virtually invisible as long as the proper part were chosen.
Is this a viable solution?
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RE: [ DRV8303 ] Bootstrap Diode Characteristics
Hi Ken,
Here are our specifications of the internal bootstrap diode:
Forward voltage VF @ IF=0.5 mA: typ: 0.676 V, max:0.85 V
Forward current IF @ VF=1 V: min: 100 mA, typ: 500 mA; max:1600 mA
Diode resistance @ VF1=0.95 V, VF2=1.05 V: min: 170 mohm, typ: 320 mohm; max: 680 mohm
Here are our specifications of the internal bootstrap diode:
Forward voltage VF @ IF=0.5 mA: typ: 0.676 V, max:0.85 V
Forward current IF @ VF=1 V: min: 100 mA, typ: 500 mA; max:1600 mA
Diode resistance @ VF1=0.95 V, VF2=1.05 V: min: 170 mohm, typ: 320 mohm; max: 680 mohm
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RE: [ DRV8303 ] Bootstrap Diode Characteristics
Hi Phil,
Thank you for sharing information!
You don't have intention to specify this in the datasheet, correct?
| Min | Typ | Max | Unit | ||
| Forward Voltage Vf | IF=0.5mA | 0.676 | 0.85 | V | |
| Forward Current If | Vf=1V | 100 | 500 | 1600 | mA |
| Diode Resistance | Vf1=0.95V, Vf2=1.05V | 170 | 320 | 680 | mohm |
Sorry, let me ask one more thing.
What is the min, typ and max of trickle charge current?
| Min | Typ | Max | Unit | Note | |
| Trickle Charge Current |
Thanks,
Ken
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RE: Any TO-220 MOSFET(Max Vds >60V Id>60A ) recommended for DRV8301?
The Typ Qg = 75nC, the Max Qq is not listed, suppose the Max Qg for STP80NF70 is 300nC. Then we have
14.4ma = 300nC x 6 x 8Khz.
I have lower down the PWM freq to 8K, and increase drive peak current to DRV8301_PeakCurrent_1p70_A. Unless the actual STP80NF70 Qg goes up to 600nC, otherwise it should be under the 30ma limit. And gate serial resister to each gate drive signal has been increase from 0 to 30 ohm. The BOOSTXL-Drv8301 use 0 ohm and the DRV8301 EVM use 1, so I increase the resistor value to 30 ohm and hope it might limit the gate current down.
Is the MOSFET so critical to use with DRV8301? We have GVDD problem in previous DRV8301 circuit, and this version the GVDD is OK before the PWM signal applied. Once the PWM signals applied the GVDD drops to gnd and can not work back to normal even if the we repowered it. It's permanently not working any more.
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Any TO-220 MOSFET(Max Vds >60V Id>60A ) recommended for DRV8301?
hi, I am doing a DRV8301 design and using ST STP80NF70 as MOSFET, my circuit is similar with BOOSTXL-DRV8301, but the VGDD is good before RUN is activated but failed and is down to gnd after the PWM signals are applied. I have take out the two SMD FETs at BOOSTXL-DRV8301 and replaced with STP80NF70s and after a while one of the gate driving signal failed. It seems some FETs will damage drv8301.
Do any one ever use a TO-220 MOSFET for DRV8301 that Max Vds >60V Id>60A and work fine? Does any ever use EKI06108([View:https://www.semicon.sanken-ele.co.jp/sk_content/eki06108_ds_en.pdf:1230:0]) or IRF1010E（[View:http://www.irf.com/product-info/datasheets/data/irf1010e.pdf:1230:0]) with DRV8301?
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RE: DRV8305 Damage
I closed all fault and than motor spinning. No damage, no high temperature on DRV8305.
But 12A current draw mosfets from the power supply and PVDD about 8V
Phase signals as shown captures.
Bad signal on the Phases. How do I get better signal.
Thanks for advice.
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