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DRV8332: Blows possibly because driving in non complimentary mode

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Part Number: DRV8332

I am using the DRV8332 with a ATMEL SAMC21.

I have already blown up 3 DRV8332 chips despite having the OC resistor set for 4A protection (which our load should never reach) and CBC set and the chip does not get warm it just blows... so no over loading to my observation.

So I am guessing we are using the chip wrongly.

As I am moving from discrete transistors to this chip I did not fully recognise the difference in PWM scheme for complimentary mode.

Also getting the SAM C21 to flip the PWM for the compliment does not seem a built in funciton. So we always were using a simpler mode, where the PWM was driving the high side and logic driving the lowside with dead time imposed by design.

However since the DRV8332 is designed for complimentray use and the high low side switching occurs automatically, with the RST purely for Hi Z mode, my question is :-

Is it dangerous to run this chip assuming non complimentary mode.

Thus when driving phase AB with A high and B low and C RST false so Hi Z, then when the PWM signal is high on A and low on B(current flows through A and B to ground.

When the PWM reaches threshold and output drops so A goes low and B is still low, then it is as if you have pulled to ground both  A and B and no current flows.

This non complimentary mode seems to work and we can drive the motor. But randomly the chip blows up.

So I am thinking we MUST implement complimentary, perhaps due to flyback protection being insufficient or some other problem.

In the end the question is: Can you use the DRV8332 in a non coimplimentary way that is safe?


RE: DRV10987EVM: Impossible to enter floating point values into "Phase resistance" parameter

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Hello Brian,

I solved the issue myself by using an other computer at office where the "commas only issue" as described in this post :

e2e.ti.com/.../2538649

is not existing.

So thank you for your effort, I notice your python howto and I continue so on with displayed value "1" in the GUI but knowing that the value is really "1,552" in the register (doing a EEPROM burn before switching from one computer to an other -_-' ).

But if TI developers Team could do something, it would be nice ;o) For example making the GUI software independ from the location it is executed all over the world.

Marco

DRV10987EVM: Impossible to enter floating point values into "Phase resistance" parameter

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Part Number: DRV10987EVM

Hello all !

I installed the GUI software to be able to communicate with my DRV10987 EVM Board.

The phase resistance parameter of my motor is 1,5 ohms.

When I try to enter "1,5" into the box, the software records "2".

The dot "." is not accepted.

When I try to enter "1500m" (I know that the GUI software has been developped with LabView ;o) ), I can quickly see "1,5" and then the famous "2" appears again.

I think this is related to the fact that I enter my values with a french keyboard (I'm from France), but I made a try with an american keyboard (qwerty) and an other try by setting my windows environment to english U.S.A. Nothing/Nada/Rien !!

Do other people cannot enter floating point values for this parameter in this Software ?

This is huggely disappointing because I have a phase resistance of 1,5 and not 2 ;o)

Thank you in advance for giving me an advice/trick/solution, because everything else works well and the DRV10987 is a very very good component !

Marco

RE: BLDC Drum Motor Controller

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The High Voltage Motor Control and PFC Developer's Kit can handle voltages upto 380V or so, and definitely not upto 1000V.

BLDC Drum Motor Controller

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Hello,

I am looking to experiment with a large drum BLDC motor (36 slot 48 pole) using high voltage (400 - 1000), high frequency (35 khz - 100 khz), and low current (below 5 amps).  Is there such a controller that can be recommended? 

DMann

BOOSTXL-DRV8323RS: Logic High on ENABLE pin sets GHA, GHB, and GHC High

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Part Number: BOOSTXL-DRV8323RS

I am doing some testing with the BOOSTXL-DRV8323RS and TMS320F28069M launchpad.  When I set the ENABLE pin high, the high side gates all go high even when I am commanding them low.  The low side gates are commanded low and stay low.  This happens before even setting the DRV8323 up over SPI.  So, it is in the default 6x PWM mode.  Is this the expected behavior?

RE: BOOSTXL-DRV8301: Reconstruction or measurement of phase voltages

RE: DRV8711: Different voltages for the MOSFETs and VM?


RE: DRV8818: Current cannot be reduced in step holding mode.

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Hi John,

Changing the capacitor to 100pF can create more switching losses by changing the blank time and the off time.

What is the resistor value? Perhaps reducing the capacitor to 470 and increasing the resistor to lengthen the off time may accomplish similar results.

DRV8818: Current cannot be reduced in step holding mode.

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Part Number: DRV8818

Hi team,

My customer reported an issue with DRV8818: the driving current cannot be reduced to target (VREF/(8*Risense) in step holding mode. In fact the current is basically fixed at arround 1A no matter what VREF is applied. Such as with VREF=0.3V and Risense = 0.1 ohm, the drving current should no more than 0.4A, while in fact it is measured arround 1A, no matter what kind of decay mode was used.

I think i have found out the root cause: it is due to long blanking time. Customer use 1nF on RCx pins, so tBLANK is about 1.4us, such long blanking time result the driving current is out of control. I have tried to reduce the capacitance down to 100pF, the problem fixed.

However, the question is, our datasheet recommends capacitance from 470pF to 1500pF, 100pF is out of this range. I do not understand why we place this limitation on Cx capacitance? How to solve this problem if 470pF is too large?

Thank you,

John

RE: DRV8871: Stall current with PWM less than with DC

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Hi Mathias,

Adding the small resistor in series allows use of the scope to calculate the current without worrying about RDSon of the FETs or any variation of the motor resistance as the motor runs.

Once the current is measured, the resistor can be removed.

FYI -- The resistor is used in the DRV8870 and DRV8872, so the current can be viewed there.

RE: DRV8432: Driver IC for automotive proportional solenoid valves (PWM controlled)

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Raymond,

The DRV8873-Q1 is in preview sampling. We will fully release it sometime in the future. If you are interested in it, you can request samples through our website.

The Rdson of the DRV8842 and DRV8432 are similar (130 mOhm and 110 mOhm respectively). However, the larger package of the DRV8432 helps it to dissipate heat better, which is why the junction-to-ambient thermal impedance is lower. One thing to note here too is that board layout also helps to dissipate heat. You may get better thermal performance on your board than the R_THETA,JA spec. If you have the time and resources, it may help to build test boards to compare the two devices under real test conditions. Either way, you many need to make space on your PCB anyway to properly accommodate thermal dissipation.

I was not aware that proportional solenoid valves had two coils per valve. Do you have an example datasheet/part number/supplier link you can share with me?

DRV8432: Driver IC for automotive proportional solenoid valves (PWM controlled)

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Part Number: DRV8432

I need some advice to choose the right driver IC for automotive proportional solenoid valves. The goal is to make it compatible with a wide range of automotive solenoid valves in the US. To make sure I dont oversize the design, I am now trying to figure out how much ampere most of the solenoid valves in the automotive world draws. Perhaps you know this?

To minimize the design I am looking for a compact IC and found the DRV8432 to be a good choice, but I want to be sure it’s the right choice, or to know if there is other, perhaps better and cheaper alternatives.

Thanks. 

/Raymond

RE: Upgrading from L293 chip

RE: DRV8881: question regarding "decay modes" of the DRV8881

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Hi Rick,

Thank you for the reply. I will read this by tonight.

Eric Sihite


DRV8881: question regarding "decay modes" of the DRV8881

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Part Number: DRV8881

Hi Rick,

I'm working with Thomas Bewley on a project to model the motor dynamic for both braking and coasting during low PWM cycles. We're also investigating the effect of the PWM frequency and the coasting during low PWM cycle, specifically at low motor duty values. We have got some experimental results, but haven't been able to find a good literature source yet.

Can you point us to a good source/documentation about the brake vs coast during low PWM cycles? I found comments and discussion on this topic online, but I haven't been able to find any good literature source so far.

Thank you,

Eric Sihite

*Note: I think I replied to one of your answer in the "question regarding "decay modes" of the DRV8881" thread, but for some reason my question does not show up in the discussion thread. It's my first time using this forum, so I'm sorry if I ended up double posting.

DRV8844: optional current-sense resistor

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Part Number: DRV8844

There are two optional current-sense resistor, SRC12 & SRC34.

How to select suitable value for them? it is for a single power application.

Thanks,

Wentong, 6/8 18'

H bridge pre drive

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Our existing predrive and the predrive used before are respectively A3941 and MC33883, both of which are H bridge. May I ask if there is a good replacement material with good delivery date for TI now and a good price?

RE: DRV8313: How to limit the current value with the COMPO pin ?

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Hi Rick,

  What I want is the adjustable current regulation function, the regulate current levels for optimal motor performance.

I find a DRV8313 reference drawing as below,Can it achieve the adjustable current regulation function ?? 

At the same time, I find the DRV8881, DRV8813 in the ESP, Which one can achieve the adjustable current regulation function ?? 

DRV8313: How to limit the current value with the COMPO pin ?

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Part Number: DRV8313

Hi, I use the DRV8313 on the new project. 

Now the torque is about 5KGf.cm.  How can I  reduce the output current , so that the motor rotating torque could lower about 3KGf.cm ???

I found the words form the specification:

I think the uncommitted comparator only can detect the current, it cann't limit the current. If I want to use the current-limiting function, How can I design the drawing??

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