Motor Drivers

Forum Post: RE: DRV8825 current regulation problem

Mikolaj Filar — Sat, 25 May 2013 12:33:00 GMT

Hi,

I've recorded a example movie (motor is enabled): http://youtu.be/x8S-rfuDhho

Driver additionally contains 3V3 and 5V regulators, some LEDs that current current probably is <50 mA .

I've also tried with impulse power supply of 15 V and have the same issue.

There is a part of schematic:

http://imageshack.us/a/img703/5162/drv1.jpg

We can see there is a capacitors: 10u, 1u, 100n, 10n, 1n for VMA and VMB. Additionally there is 470u LOW-ESR capacitor (on the schematic it looks like it's nearer VMA, but on the board there is similar distance). Before D1 diode there are also a lot of 47u, 10u, 1u and 100n capacitors and one 2200u.

and there is a part of layout:

http://imageshack.us/a/img254/4854/drv2.jpg

The 470u capacitor is more on the left side of the board. The GND is highlighted.

Best regards,

Mikolaj

Forum Post: RE: GUI Composer Generates an Error with my InstaSPIN DRV8312-69M_KIT

Rick Duncan — Fri, 24 May 2013 21:31:00 GMT

Hi John,

I suggest you also post the question in the "InstaSPIN Motor Solutions Forum". This forum is geared to InstaSPIN questions.

Also, please note that your post may move to this forum; I have asked for assistance from them.

The link to the forum is http://e2e.ti.com/support/microcontrollers/c2000/f/902.aspx

Forum Post: RE: SPI commands in DRV8301

Jeremy Dwyer — Fri, 24 May 2013 17:46:00 GMT

It appears that the DRV8301 always and only sends the register value the word cycle after the SPI master issues the read command for that register (except SR1 is sent after writes). Unfortunately a macro I was using did not generate the proper read command, so I did not evaluate this before.

Forum Post: RE: Confused about DRV8432 in parallel mode

Fernando Mart��nez — Fri, 24 May 2013 06:29:00 GMT

Okay, everything is clear now..

Thank you very much for your help.

Forum Post: RE: GUI Composer for DK-LM4F-DRV8312 will not open properly

MartinS — Wed, 22 May 2013 21:29:00 GMT

Adrian,

Our apologies for delayed response. Unfortunately, the application that Dobrin attached had some bugs in it. Attached .zip file contains a slightly tweaked application that I have verified with LM4F board, a motor that ships with DRV8312 kit and GUI Composer Runtime 1.8.0.1. (Please visit the site to view this file)

In summary you would need to download attached .zip file.

Install GC Runtime 1.8.0.1 from http://processors.wiki.ti.com/index.php/Category:GUI_Composer#Windows

Then unzip downloaded app into GCInstallRoot\guicomposer\webapps directory.

GC Runtime 1.8.0.1 contains the fix that you helped Dobrin with.

Again, I am sorry about the delay in getting back to you.

Martin

Forum Post: RE: Very little current [DRV8837]

Ryan Kehr — Tue, 21 May 2013 20:51:00 GMT

Jose,

Sorry for the uncertain statement.

The current when VCC is removed is the same as the I(vmq) number in the tabular data which is the VM sleep-mode supply current. When VCC is removed, the device automatically enters the sleep state and the current is nominally 30nA and max. of 95nA as the table implies.

The OCP circuit is not "in-line" with the output FET as shown in the block diagram. It is essentially a current mirror that scales the current in the output FETs. This scaled current is compared to an on-chip reference to set the OCP trip point. So, you do not need to consider this in the voltage drop calculations.

Forum Post: RE: DRV8801

Ryan Kehr — Fri, 17 May 2013 21:54:00 GMT

Eli,

1) Up to 200kHz is acceptable on the ENABLE input. This should be more than enough for a motor application. Typically we see 30kHz used for most applications.

2) The input deglitch time is the only thing you need to be concerned with. The deglitch range is 400ns - 800ns (max). A pulse of this duration will be ignored.

3) Crossover is "dead-time" to avoid current shoot-thru. This is the transition time between switching one channel high and the other low or vice-versa. I need to research the propagation delay more.

Forum Post: RE: Low Noise, Fast H-Bridge

Ryan Kehr — Fri, 17 May 2013 20:57:00 GMT

Fatin,

Rise/fall times for DRV8837 are typically 100ns with a max. of 150ns as given in the datasheet. Although, I have to be honest and am not sure what the load was under these test conditions and for your load it will surely be different.

The EVMs are $25, so pretty cheap to check out.

http://www.ti.com/tool/drv8837evm

If you need a device in the family with a spice model, the DRV8832 has a model. Scroll down under the MODEL heading:

http://www.ti.com/product/drv8832

Forum Post: RE: driver for bipolar stepper (3-4A) with step and dir input

Ryan Kehr — Fri, 17 May 2013 18:14:00 GMT

Silvio,

We do not have anything in the portfolio other than what you mentioned at this time.

However, we are working on something so check back within 1-2 months time.

Forum Post: RE: How to rotate BLDC motor Counter-clock wise which is bundled with DRV8312-C2 Kit.

Hale Petersen — Fri, 17 May 2013 18:07:00 GMT

I was actually able to figure it out, sorry i didn't post back for others to see. I had to play around with the commutation states that the motor was running though. Some were more smooth than others, but the changes I made are shown below.

//original for clockwise rotation

if (hall1.HallGpioAccepted==5)

pwm1.CmtnPointer = 0;

else if (hall1.HallGpioAccepted==1)

pwm1.CmtnPointer = 1;

else if (hall1.HallGpioAccepted==3)

pwm1.CmtnPointer = 2;

else if (hall1.HallGpioAccepted==2)

pwm1.CmtnPointer = 3;

else if (hall1.HallGpioAccepted==6)

pwm1.CmtnPointer = 4;

else if (hall1.HallGpioAccepted==4)

pwm1.CmtnPointer = 5;

//mine for counter-clockwise rotation

if (hall1.HallGpioAccepted==6)

pwm1.CmtnPointer = 0;

else if (hall1.HallGpioAccepted==4)

pwm1.CmtnPointer = 1;

else if (hall1.HallGpioAccepted==5)

pwm1.CmtnPointer = 2;

else if (hall1.HallGpioAccepted==1)

pwm1.CmtnPointer = 3;

else if (hall1.HallGpioAccepted==3)

pwm1.CmtnPointer = 4;

else if (hall1.HallGpioAccepted==2)

pwm1.CmtnPointer = 5;

Forum Post: RE: Power upgrade to HV Motor Control and PFC kit

ChrisClearman — Fri, 17 May 2013 17:52:00 GMT

there is also a 10A fuse on the kit

be sure if you change the power module you look at the current scaling for the ADC input to make sure you can measure those values and then convert them appropriately in SW.

Forum Post: RE: Control of Ac Motors

ChrisClearman — Fri, 17 May 2013 17:49:00 GMT

V/Hz control of ACI motors is pretty straight forward, there are some old examples here: http://focus.ti.com/docs/toolsw/folders/print/sprc194.html

If you want to introduce an inner torque controller for better performance / dynamics I would look at InstaSPIN-FOC

Forum Post: RE: Unipolar Microstepping

Gabriel Mejia — Thu, 16 May 2013 22:51:00 GMT

It is solved, the circuit of FIG works well. the problem was on a track in contact with the pad under the DRV8825.

thanks

Gabriel Mejia Ruiz

Forum Post: RE: DRV8811EVM Question

Ryan Kehr — Thu, 16 May 2013 15:11:00 GMT

Mike,

In full step, your current waveform should look similar to below. Notice it is bi-directional current.

This is showing 1 phase and the step input is shown in channel 1. The other phase is 90 degrees out of phase.

Forum Post: RE: DRV8412 PWM help

Ivan Debelec — Thu, 16 May 2013 09:05:00 GMT

Hello again...

Can you please post here pictures from PWM input on DRV8412 kit??? If is possible i'd like to see all 4 PWM inputs at speed of 100 rpm and current aprox. 2A...

I'm trying to make my stepper move with C2000 Launchpad i get some rotation but sometimes i get some strange hitches...

Thanks...

Forum Post: RE: DRV8832 Reliability

Ryan Kehr — Wed, 15 May 2013 18:31:00 GMT

Andrew,

Our standard reliability data is available on our website at the link below. Scroll down to "Quality & Environmental Data" heading and click on the "View" button for the package option you are interested in.

We recently released an automotive grade of the device at the link below:

http://www.ti.com/product/drv8832-q1

Unfortunately, your specific request I can't provide any background on as I don't have point failure information. The case I can think of is one of the inputs getting stuck HIGH while the other is LOW. This condition would happen if any ESD damage occurred at the inputs causing a short to one of the supply rails. If this is your concern, you would need to add additional monitoring circuitry on the outputs to ensure they are in the correct commanded state based on your software.

Forum Post: RE: BLDC motor control basics using DRV8312/8313 and an MSP430/Arduino

Ryan Kehr — Wed, 15 May 2013 18:20:00 GMT

Sashwat,

All of the code and hardware files for the DRV8313 are at the link below:

http://www.ti.com/tool/drv8313evm

You can use this as a starting point.

Forum Post: RE: DRV8843 3.3V Regulator Problem

Wilson Zuo — Wed, 15 May 2013 08:18:00 GMT

Hi Jake

It is strongly recommended that you put extra 100uF near by VM and GND directly. This is important for almost motor drivers. Especially when you do not have current regulation resistor, the peak current could cause obvious ripple on VM pin. All the driver functions will work correctly as long as the VM is stable and within the operation range.

You can have test again with the 100uF cap manually add to you current board. Make sure add the cap near by the driver side other than the power side.

Thanks.

Wilson

Forum Post: RE: DRV8312 bootstrap diode current limit

Andrew Kuklinski — Tue, 14 May 2013 13:15:00 GMT

Excellent news Ryan. Thanks for your support on this issue.

Best regards, Andrew Kuklinski

Forum Post: RE: DRV8811 Decay Mode Select

Mike Tucker — Sat, 11 May 2013 01:53:00 GMT

Ryan, Wilson:

Thank you Wilson for your comments. Yes, I am running in full-step mode with a 1.8 degree motor. Can you summarize the best settings for the highest torque at 12 VDC motor voltage? I do not need precision steps so I am guessing that the highest torque at 700 steps per second would be achieved using full steps with slow decay?

Mike