Hello Rick-san,
Is there any update?
Another customer ask me same question.
I think there is some data like bellow.
*For example : DP83822
(Please visit the site to view this file)
Regards,
Naoki Aoyama
Part Number: DRV8884
Hello,
Our customer use the DRV8884.
The customer apply voltage to Decay pin.
Perhaps, there are three threshold voltage at Decay pin.
Vth1: between Vi1 and Vi2
Vth2: between Vi2 and Vi3
Vth3 between Vi3 and Vi4
Could you tell me the value of threshold voltage?
I know it operates correctly by input 100mV, 300mV, 1V, 2.9V.
The customer want to know the tolerance.
one more question
When the customer use Slow/Slow decay, is it possible to left open the Decay pin?
Best Regards,
Naoki Aoyama
Part Number: DRV8825EVM
Hi,
I am looking for an easy to implement stepper motor drive set-up to introduce controlling of stepper motors as part of a laboratory session for students from the Diploma in Electronics. Would you be able to advise if the DRV8825EVM is a good choice?
Appreciate if you could also suggest a suitable motor that can be interfaced to this.
Thanks Rick - they cound have made this a litte more obvious I think...
Part Number: DRV8303
Hello
I am doing a quick schematic using the DRV8303 and there does not seem to be any pull down resistors on the Gate driver outputs. I cant seem to any data on the pull downs in the datasheet and there are none present in any of the reference designs, but I would hat to get the PCB made up without them if they are needed.
Thanks
Graham
Hello
What are the Pro's and Con's to both high side or Low side PWM switching when using the DCR8303? (high side N-channels)
I was looking to use the 6-PWM modem PWM the high side and just use standard IO for the low side for the 6-step commutation. The 3-PWM mode looks interesting however I was hoping someone could highlight the issues created and how they are resolved... Ie, with 6 step you may need GH_A & GL_B high and all switches on LEG C off, as far as I can tell in 3-PWM mode you can not switch Leg C off completely (perhaps 3-PWM mode is more suited to sinusoidal or FOC control?). If I could disable leg C completely (on this step) it is also apparent that the motor will be driven in bipolar four quadrant configuration which may be useful as future proof.
If possible, please can someone show me where I can find some scope traces of the motor phases when the 3-PWM mode is used?
Thanks
Part Number: DRV8301
Hello there,
I have developed the BLDC drive on DRV8301(referenced on Booter pack). The developed board is working good. But I have an issue regarding the setting of the Gains .
The minimum Gain is 10VpV ,and my hardware I designed is having 20VpV gain, I tried changing the gain to 20VpV through SPI , But everytime It defaults to 10VpV.
Is there any way to set the gains permenantly to some set value?
Hi Rick,
Further update. I have a 1uF capacitor across the OUT+ and OUT-. This works fine in my prototype test system but it seems to be causing the issues on my PCB.
Here's what happened. I tried increasing the output capacitance (across OUT+ and OUT-) and the FAULT started happening at a lower voltage so that gave me the idea to remove it altogether and see what happens. Voila, no FAULTs and I ramped up the voltage to 24V without any issues (I didn't go any further because that is the maximum voltage I plan to use). All this was happening at about 12.5% duty cycle. To test it out further, I switched to 25% duty cycle and the DRV8800 went up in smoke. My PWM frequency is 100Hz.
Do you know why having a capacitor across the outputs would cause any issue and trigger FUALTs?
What might cause the chip to blow up at 24V when increasing the duty cycle especially with all the in-built protections?
I appreciate any insight into the above issues and what approach I should take to remedy the situation.
Thanks,
Peeyush
Part Number: DRV8702D-Q1
Hi,
two question regarding DRV8702D-Q1:
1) R(VDRAIN) 100-Ω series resistor (-> The R(VDRAIN) resistor should be used between the VDRAIN and VM pins to minimize current to the VDRAIN pin if no external reserve battery protection is implemented on the VDRAIN pin).
-> If there exists an inverse-polarity protection, can the resistor be left away? The inverse-polarity protection sits in the entry area of the electronics, not directly at VDRAIN.
2) Do you have details on the internal resistance pull down of the sleep pin?
Thx
Part Number: DRV10983
Hi
Our customer faced the following error by increasing rotation speed.
I believe it represents Lock2 : Abnormal Kt.
DRV10983 is configured for customer motor to be used by referring Tuning guide (SLOU395D).
Could you please advice how to avoid this error?
BestRegards
Hi Peeyush,
I had ruled out overcurrent because you said you had added a 10Ohm series resistor, and the fault was not consistent at ~1.2ms.
Placing a large capacitor like a 1uF can cause overcurrent events as the voltage increases.
Regarding the damage, it is difficult to speculate. How are you controlling the PWM inputs at 100Hz?
Hi Rick,
Thank you for your reply.
I did place a resistor temporarily to test it out but it was placed after the capacitor (see picture) so I believe it becomes immaterial whether the resistor is placed on not for the overcurrent condition. Interestingly, it works nicely in my prototype with the capacitor. The only other difference between prototype and PCB layout is that in the prototype version the capacitor is very close to the OUT+/- terminals while on the PCB it was further down the trace about 15mm from the OUT+/- pins (possibly adding some inductance there). Since it worked in my prototype, I kept the capacitor in my final schematic for the PCB for noise filtering purposes. I see two faults in my scope, one lasting ~1.5ms and the other lasting ~2.5ms (~2 X 1.2ms) and they alternate when using the capacitor and Vbb > 15V.
As for controlling the inputs, I'm using 3.3V MCU to generate the pulses for the ENABLE pin while keeping the PHASE high or low depending on which direction I want to turn the motor. I always ramp the duty cycle about 0.4% every 200ms. So, let's say the user application requests a duty cycle of 25%, it takes appropximately 12.5s to reach that value. FAULT, MODE and SLEEP are pulled up using 10k resistors. VREG is not connected. I'm almost using the suggested PCB layout except that I have only 10uF ceramic bulk capacitance (due to space considerations) and the 1uF output capacitor which I have now removed.
Just when I though I figured out one issue, a bigger one has popped up. I would really hate to change my PCB in lieu of another motor driver. DRV8800 meets my requirements very nicely.
Please let me know if you need more info.
Regards,
Peeyush Garg
Hi Jesal,
Are you using EN_GATE to disable the device? This will reset the SPI registers.
Part Number: BOOSTXL-DRV8301
Hello
I tried to use the LAUNCXL-F28027F + BOOSTXL-DRV8301 to control the speed of GT2820/04 motor. the motor's parameters: Cell count:3-4S, RPM/V=1460, no load current=3A,Max RPM=17000, Max current=48A, number of poles=14
Max speed that I need is about 3000 rpm. I ran lab2b and lab2c to identify the motor's parameters. in these labs when I changed the "SpeedRef_krpm" the motor's speed didn't change. why does it occur?
below shows the achieved result with vdc=13v:
#define USER_MOTOR_NUM_POLE_PAIRS (7)
#define USER_MOTOR_Rr (NULL)
#define USER_MOTOR_MAGNETIZING_CURRENT (NULL)
#define USER_MOTOR_RES_EST_CURRENT (1.0)
#define USER_MOTOR_IND_EST_CURRENT (-1.0)
#define USER_MOTOR_MAX_CURRENT (8.0)
#define USER_MOTOR_FLUX_EST_FREQ_Hz (20.0)
#define USER_MOTOR_Rs (0.01457627)
#define USER_MOTOR_Ls_d (2.113534e-09)
#define USER_MOTOR_Ls_q (2.113534e-09)
#define USER_MOTOR_RATED_FLUX (0.01733333)
when I use thses achieved parameters an error appeared as "USER_ErrorCode_ctrlFreq_Hz_Low". and when I increase the Ls_d and Ls_q value, this error dosen't occure . but I cant change it's speed. How can I solve these issues?
Regards.