Brian,
I increased the Open to Closed Loop Threshold from 12Hz to 25.6Hz.
Set the T Control Advance to 600us
All other settings as before.
With the speed set to 100 I get
Motor speed 1638Hz
speed command 19%
Speed cmd buf 23%
with the speed set to 400 I get
Motor speed 1638Hz
speed command 78%
Speed cmd buf 23%
Thanks
John
Hi,
In case of the DRV8838, you will need to leave EN high at all times to drive the Outputs and switch the logic on the PH pin. Therefore, you can control the speed by controlling the frequency of the PH switching.
Look at Section 6.6 and the DRV8838 timing diagram in this section to learn more.
The frequency can be from 0 to 250kHz.
Part Number: DRV8323
I love the concept of integration the DRV8323 provides.
Does TI have any plans to introduce any 80-100V version of DRV8323 . I am so frustrated with all the discrete components that we are currently using.
Hi Rick,
System is powered up when ESD contact test was done. Test is done while board is installed in the unit (big grounded metal box). ESD gun ground was connected to chassis GND - same potential as board GND.
With bidirectional 43V TVS AOUT failed on second -8kV hit (we haven't tried -8kV on BOUT). It passed +8kV on both outputs.
With unidirectional 43V TVS board is passing both +/- 8kV. We are planning to keep these TVSs in design.
My main question/concern is impact of forward biased diodes in parallel with low side FET body diodes. Based on data sheet there should not be any. In drive current mode (PWM ON) current flow is opposite. In fast and slow decay mode (per Figure 7) appropriate FETs are being turned on and there is no current thru body diodes and TVSs. Correct?
We figured the reason for occasional lockups after ESD hits. Reset line drive from our uP gets low. Working on fix.
Regards,
Darko
Part Number: BOOSTXL-DRV8305EVM
Customer is having some trouble with the BOOSTXL-DRV8305EVM. He is using the InstaSPIN FOC software with an 18V 7 pole SMPM motor.
He is trying to get maximum torque at the initial motor startup. and maintain a strong torque throughout using the speed control feedback loop (Lab 5b). His problem is that he has very little torque throughout the entire process. Using Lab 4 (Torque Control), when he increases the IqRef value considerably, he still have very little torque. It doesn't take much to stop the rotor from spinning.
Can you let me know which parameters he should be changing to maximize the torque my motor delivers? Can you refer to any relevant documents he may find will resolve this problem?
Regards,
Naser
Part Number: DRV8323R
I use DRV8323RH for BLDC motors.
When I use 1 PWM mode, the temperature of 8323R goes up to 40 celcius degree.
But, When I use 6 PWM mode, the temperature of 8323 R goes up to 65 celcius degree.
I used a thermal camera for measuring temperature.
1-PWM mode is used to 6-step control and 6-PWM mode is used to SVPWM control.
I wonder it is normal.
If it is not normal, what I should do for 6-PWM mode?
Part Number: CSD88539ND
Hello,
Could you tell us about CSD 88539?
What is the avalanche (EAR) value under the following conditions?
※ This question is about EAR, not EAS.
VDD = 30 V,
Vgs = 20 V -> 0 V,
ID = 10 A,
L = 100 uH,
RG = 25 ohms
Tch ≦ 150 ° C., test time 1000 h
On = 1 us, duty cycle ≦ 1%
Thank you.
Hi Madhu Chandra K,
There is no need to reduce the current limit resistor.
My understanding is that your part is working fine but you are measuring the current in the wrong location. Have you tried measuring the current in the place I suggested?
Let me highlight this for you:
If you are measuring the current in the wrong location, then the average measured current is going to drop when you add the diode as you have observed.
Please try this and let me know if this solves your issue.
Best,
Grant
Part Number: DRV8838
Hi
Could I input the PWM signal at EN pin on DRV8838 ?
I know the DRV8837 support the PWM control, but my exist hardware is DRV8838 and it needed speed control .
I 'm not sure if I can input the PWM at EN pin on DVR8838
thanks
Part Number: DRV10975
Hello all
If the PWM input signal has a slow rise time,Does it cause the PWM control failure? What is scope time scale for PWM voltage high level?
Thanks.
Part Number: DRV8881P
So, we have a board that uses a bank of DRV8881Ps to drive a number of motors without issue. Now, we are looking to reuse the same board to drive some resistive patch heaters (with pwm from our controller).
However, according to testing performed when we first brought up the boards, it looks like there are some issues when we try to drive a purely resistive load. It seems to want to engage current-limiting mechanisms or something along those line despite never actually reaching overcurrent.
So, we can't find any specification in the datasheet which indicates a failure or limiting mode at high di/dt. Is that a hidden spec? If so, is there any hope for reusing this part to drive our heaters, or do we move on?
Part Number: DRV8320
I am unable to configure my DRV8320S in 1XPWM mode in one count. It takes more than 3000 count to configure it. Also the IC is getting heated up to 60*C. What may be the possible cause. Even after configuring, i am unable to see comutation output on PINS of DRV.
Part Number: DRV8312
Tool/software: Code Composer Studio
Hello,
I'm working with the DRV8312EVM developped kit with the motor BLDC DT4260-24-005 24VDC 4000RPM (just starting). I ran the example code BLDC_sensorles, the motor runs just untill the level 4. AT level 5, when I close the loop, it didn't work. I think the problem coule be in the CMTN_TRIG module.
Below is the CmtnTrig and ZcTrig signal mesured. I think is not normal comparing with the guide file (which say that CmynTrig should appear 30° after the ZcTrig). the motor in this case still works.
Thank you in avance for your support,
Trung