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DRV110: Ripple on Input Voltage

February 6, 2018, 5:00 am
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Part Number: DRV110

I'm trying to implement a economizer circuit with a DRV110.

In the first implementation I wasn't able to keep the relays closed.

After some tweaking (first response) I got the relay to stay closed but had massive ripples on the input voltage. 

12V Input 
Ihold 0,1A -> 606k Ohm
Ipeak 0,4A -> 149k Ohm
tkeep ,5s -> 47µF

Rsense 1 Ohm

Mosfet DMN6040

With this setup I get the following measurements:

Voltage @Relay

Voltage At Relay

Voltage at Mosfet

Voltage At Mosfet

Voltage At Rsense

Voltage at Rsense

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DRV8320: Direction control in 1x PWM mode

February 7, 2018, 12:39 am
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Part Number: DRV8320

Hi

We use DRV8320H, and assume 1x PWM mode.

The direction of rotation can be controlled by INHC (DIR) from MCU.

Are there any procedure of changing direction while motor spining?

Can we change direction without any consideration ?(motor speed, BEFM and so on)

BestRegards

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RE: drv8320: Operation of sensored softwere

February 7, 2018, 4:06 am
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Hi James

The VCC of hall IC would be provided from the board, but it will be 3.3V.

If larger VCC is required to hall IC to be used, it should be provided from other supply.

Is my understand correct?

By the way, I got the following hall signal from powering hall IC of motor, with spinning by finger.

Do you think this output of hall is IC correct?  

BestRegards

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RE: Motor driver IC with open circuit / short circuit detection

February 7, 2018, 5:39 am
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Hi Rick

I tried in the lab the next solution, seems like it works good

My question is - should i disconnect the comparator from the motor before motor's operation ?

Is there any concern that the comparator will affect motor's operation and/or DRV sensing (current, fault etc')

There is different tolerances for comparator's input impedance, for the DRV also..

So what do you think ?

If so, how do you suggest to disconnect it ?

Thanks

Eduard

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RE: DRV8412: current limiting and increased voltage at OUT pins

February 7, 2018, 7:05 am
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Hi Atharva,

>> What is the current limit for cycle by cycle limit ? I have connected a resistor of 27Kohms between the OC_ADJ pins and GND. Also the OTW and FAULT pins are at 3.2 V (I have given a pullup to Vreg). The Vreg voltage is at 3.2 V. Also M3 and M2 pins are given logic 0.

The current limit is set by the OC_ADJ resistor, and is 9.7A +/- 20%. If M1 is logic 0, the device will stop driving until the output pair (A/B or C/D) are cycled. If M1 is logic 1, the device will stop driving using latched shutdown.

>> Yes, the output voltage is 0.5 V higher at all times.

The 6.5 appears to be ringing on the output. To me the bigger concern is why are the outputs at 4V with PVDD=6V with no load? The output should be ~PVDD V.
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DRV8412: current limiting and increased voltage at OUT pins

February 5, 2018, 7:07 am
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Part Number: DRV8412

Hello

I am currently working on DRV 8412 and my application is to use it just for bidirectional current control. So firstly,I wanted to ask if we can use all the half bridges individually?

Secondly,when I keep one H bridge on ie the High side mosfet of A and low side mosfet of B is ON (permanently on without switching ) then after increasing the load beyond 0.85 A or so the output OUT_A is not constant. The waveforms show that it is trying to turn off the High side mosfet of A. I am attaching the waveforms. The first waveform is the zoomed in version of the 3rd waveform. The second waveform is of the normal operation of the High side mosfet(which happens below 0.85 A load current). 

And thirdly, there is another issue regarding the increased output voltage at the OUT_X pins when a constant voltage is provided at the PVDD_X pins and the PWM_X are set to logic 1. There is a rise of voltage at the OUT_X pin of 0.5 V. For eg if PVDD_A is given 6 V then I am receiving an output at OUT_A of 6.5 V  

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RE: drv8320: Operation of sensored softwere

February 7, 2018, 7:15 am
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Hello na na78,

I think you are using the correct header file, so things should be fine from a software side.

However, those Hall outputs do not look correct. The Hall signals that the DRV8320EVM expects should be clean on/off logic signals between 0 V and 3.3 V.

Check the datasheet for the motor or Halls to see what supply voltage the Halls need. You are correct, they may need a higher voltage supply. Double check that the sensor outputs are open drain. If they are, then you can connect them directly to the EVM because the EVM has pull-up resistors to 3.3 V.
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drv8320: Operation of sensored softwere

February 5, 2018, 3:08 am
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Part Number: drv8320

Hi

I'm evaluating DRV8320H using BOOSTXLDRV8320H EVM.

The requirement is sensored application, so I followed the user guide, the sensored project was built and loaded to device. 

I believe there is no problem up to this point.

However, I could not start motor in BOOSTXL-DRV832x GUI.

I got the following status.

Regarding to status of LED1 and LED2 on MSP430F5529LP board, LED1 is "toggle", LED1 is "on".

The other configuration is below.

Before this evaluation, I populated R35, R36 and R38 with 0ohm for PWM inputs.

And I set 1x PWM Mode in the GUI, and start motor driving.

The tool version is below.

GUI : v1.0.0 (3fb7e5)

CCS : version 7.4.0

Motor: TelcoMotion DT4260-24-055-04H-TI

As a side note, a sensorless software worked properly with same motor.

Can you see the reason why my sensored software is not worked?

BestRegards

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RE: DRV8320: Direction control in 1x PWM mode

February 7, 2018, 7:34 am
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Hello na na78,

For the DRV8320, you should be fine to change direction without consideration to speed and BEMF. If there are any issues, the DRV8320's protection features should shutdown the device before any damage occurs. However, depending on your motor load, you may see better system performance by slowing the motor before changing direction.
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RE: DRV8834EVM: EVM App ITRIP A question

February 7, 2018, 7:48 am
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Hi AJ,

Thank you for pointing out this incorrect calculation in the GUI. We measured the ITRIP under the same conditions, the result is the same as you. I believe the GUI is incorrect. We will confirm where the issue resides (GUI or firmware) and correct it in the future.
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DRV8834EVM: EVM App ITRIP A question

February 4, 2018, 9:56 pm
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Part Number: DRV8834EVM

Hello.

I used DRV8834EVM have a question need you help. I set AREF A to 0.22V check Motor Current is 220mA. But App show ITRIP is 137.74mA.

In SLVU701A User's Guide Equation 1 is  ITRIP = xVREF / 5 · RSENSE , with RSENSE =  0.2 Ohm. I think ITRIP should be around 220mA.

May I ask what details have been ignored? Thank for help~

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RE: Motor driver IC with open circuit / short circuit detection

February 7, 2018, 8:22 am
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Hi Eduard,

The comparator should not affect the operation of the DRV8833, but the DRV8833 may affect operation of the comparator.

What is the input voltage rating of the comparator when VDD=3.3V. Are there some paths that could raise the VDD voltage?

If there are, you should protect the comparator. This can be done by either:
A CSD13381F4 can be placed between the motor and each input of the comparator to connect/disconnect OR
After confirming with the comparator manufacturer, possibly adding resistors from the motor to the comparator to limit the current.
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Motor driver IC with open circuit / short circuit detection

December 20, 2017, 5:19 am
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Hi

Is there a motor driver with the feature to detect if motor is connected or not ?

For example a driver connected to a DC motor

In idle state (no motor operation), the motor can be disconnected machanically from the driver.. so i need to detect it

Thanks

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RE: DRV8801-Q1: about PHASE control

February 7, 2018, 9:53 am
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Hi Sagara-san,

(1) If CW / CCW switching is performed by PHASE signal while ENABLE = "H",
Is there a problem with the drive stage or IC?

>> The answer depends on the operating conditions and system design. Assuming the absolute maximum ratings are not exceeded, there should be no problem doing this. Please see additional details below.

(2) Is it necessary to change CW / CCW while ENABLE = "L"?
If yes,
Is it necessary to confirm the motor stop?
Under what conditions can you change PHASE even if you keep ENABLE = "1"?

>> Assuming the absolute maximum ratings are not exceeded, there should be no problem doing this. Please see additional details below.

Additional details. Switching the direction of the motor instantly can result in an overcurrent condition. The overcurrent circuitry will disable the outputs for 1.2ms resulting the current flowing back to VM. If VM is near the maximum recommended voltage and the bulk capacitors are too small, the device could be damaged.

It is recommended to stop the motor prior to switching directions for this reason.
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RE: DRV8308EVM: motor rotates with noise and gets hot after a while

February 7, 2018, 3:25 pm
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Hello Hong,

Do you have the Hall sensors and the motor phases connected to the correct terminals? Sometimes if the order of the Hall sensors and motor phases do not correspond, you can have issues like this.

Also are the Hall sensors single-ended or differential?
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DRV8308EVM: motor rotates with noise and gets hot after a while

February 7, 2018, 1:45 pm
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Part Number: DRV8308EVM

I am evaluating DRV8308 chip for my motor using DRV8308EVM.  it is known that hall sensor is 0 degree aligned (from vendor with integrated motor/hall sensor).  I started motor using the open loop: pwm mode and 120 deg commutation.  motor can rotate but with noise and bumpy visible bumpy rotation and motor can get really hot after a few minutes.   Hall sensor's output shows the uneven speed too.   I adjust ADVANCE value and speed will be impacted but the noise, uneven speed and motor getting hot remains.   I tied to change to 180 commutation (sine) and it won't help.   Lockn signal come and go.    Any tips what should I do to improve the smoothness of rotation and reducing the heat generated by motor?

The motor's specification: 12V with no load speed 63400 rpm, nominal speed 46800rpm  (the motor is integrated with a 15:1 gearhead and with a simulated load).  phase resistance = 12ohm, inductance 0.118 mH.  I have run the motor with the motor mfg's controller which can run quietly and won't get hot at all.

thanks,

Hong

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DRV8801A-Q1: drv8801a-q1: Can i drive an external FET for reverse battery protection using Vcp?

February 7, 2018, 7:39 pm
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Part Number: DRV8801A-Q1

Can i drive an external FET for reverse battery protection using the charge pump of the DRV8801A-Q1? There is no information in the datasheet about the charge pump. In the DRV8703-Q1 it is recommended to drive an external FET with the charge pump and it can source minumum 12mA while Vcm>13.5V.  Im assuming since its integrated FET's the charge pump of DRV8801 will not be able to source as much current but what would that number be?

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RE: DRV8305: Recommended VCPH Capacitor Voltage Rating

February 8, 2018, 6:27 am
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Hi Paul,

Thank you for pointing this out.
Yes, the capacitor rating should be higher than 18V. We will correct this in a future datasheet update.

FYI -- under normal operating conditions the capacitor should be <11V.
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DRV8305: Recommended VCPH Capacitor Voltage Rating

February 7, 2018, 10:26 pm
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Part Number: DRV8305

I noticed that the recommended VCPH capacitor voltage rating is 16V in the DRV8305 datasheet. However, the charge pump over voltage protection V_VCPH_OVLO maximum is 18V. If the over voltage protection does not stop the charge pump from generating a voltage greater than 16V, then the 16V rating would be exceeded. Should a capacitor with a voltage rating greater than 18V be used instead of 16V rating?

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RE: DRV8323R: I think I found major defect on DRV8323RS.

February 8, 2018, 7:12 am
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Hi David,

Thank you for the schematic.

As you noted the default is 6x. If INLA is 1, INHB is 1, and INLB is 0, you may have current flow from the B phase to the A phase when the device is enabled. To eliminate this possibility, two of the three phases should be off.

From your schematic, phase C can be turned off if you know the state of the INHC pin on the board and set INLC to the same state.

Phase A and B do not appear to be known. There are multiple methods to address this.

If you plan to use the stop state, this would be very beneficial. Adding the ability to turn off the hall pullup voltage would allow entry into the stop state. By disabling the 3.3V, the internal pulldowns will set the INLA, INHB, and INLB low.

Prior to enabling the device, use the stop state as described above and set the INHA to low to disable the all phases.

Once enabled, the device can be set into 1x PWM mode and remains in the stop state since INHA=INLA=INHB=INLB=0.

Finally, the pullup voltage can be turned on and the INHA can drive the PWM input.

Please double check this procedure. This is based on the datasheet and has not been verified.
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