Motor Control ICs Forum Discussions
Hello, I have found a weird bug/error in the PWM sequencing during bootstrap charging in a custom application using IMC101T-Q48.
Phase V low side PWM is going HIGH a bit before phase U low side and then staying HIGH until it should go LOW which it does fine. I have not observed any errors later in the bootstrap charging process or during normal operation.
Some further investigation proved that this phenomenon happens with a switching frequency of 10kHz and 8kHz, but not at any other frequency I tried. I have tested the following frequencies where it does not happen: [kHz]
4, 5, 6, 7, 9, 9.9, 10.1, 11
This is not a major issue as the bootstrap charging still works, but it decreases the confidence in the product.
I am using iMotion_SD V5.03.07 package.
See attached scope captures for illustration.
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Hello dear community!
I am searching for a component with at least the specifications of the previous one! It's important that it is pin-compatible and available. There's already a post, but unfortunately, it wasn't helpful for me....
It concerns the obsolete component: BTS7740G / BTM7740G in SO28
Thank you in advance and best regards!
Show LessI'm working with a mix of IFX007Ts and the older BTN/BTS7960s (latter on dev boards, former for custom designed PCBs).
I'm working well below their actual current limits and using them to run a very sharply spiking waveform (surge of increasing current enters a low resistance inductive load (BLDC coil) with the driver in the HIGH ON state for tens of microseconds, then the river goes to the LOW ON state and the current recirculates for hundreds of microseconds until it drops to near zero, then the cycle starts again). The peak of the waveform is at 15A for tens of microseconds, well below the 43A spec of these half-bridges. The mean average over time is more like 4A, a tiny fraction of what these chips are rated for. Inhibit is permanently held high.
On the dev boards though there are 10K resistors on the slew rate pins, limiting how fast the half-bridge lets the current rise when it has just switched state.
Would, with a high PWM rate being applied to the Input pin of such a half-bridge, using smaller slew rate resistors, or directly grounding the slew rate pin, further reduce any heating inside the half-bridge chips which may be occuring? When it comes to the IFX007T custom board, should I be fitting much smaller Slew Rate resistors to reduce the potential for overheating the half-bridge chips (I'm not in a situation where I'm concerned abut the increased EMI possible from high slew rates with large currents, but I'd like to keep the slew rate limited as a way to make by low resistance load have a shallower gradient of current rise if doing so does NOT increase heating in the IFX chips)?
I would assume the only way that an IFX007 can limit the slew rate is by gradually taking the internal MOSFETS through higher resistance conducting states before reaching the minimal resistance of being fully ON, and this would surely generate more heat than switching straight to being fully ON??
I've seen rumoured discussions of IFX and BTN/BTS half-bridge driver chips being prone to overheating when run at high PWM rates, is this a condition which only occurs when PWMed or currents at close to the 43A? Or is this a condition which specifically occurs, potentially even at much lower time averaged currents , when a large resistor is used to set a slow slew rate?
Thanks
P.S. is there any reason that most exmaple IX/BTN/BTS boards including Infineon's own Arduino form factor triple IFX007T BLDC shield seem to use series resistors on the Input and Inhibit pins? Can't those just be driven directly from a 5V microcontroller's output pins? Aren't series resistances on these lines liable to cause the voltage at the Input and Inhibit pins to jump around somewhat when in electrically noisy environments when compared to the more tightly fixed voltage that would be achieved at the pins with a direct connection to an MCUs outputs?
Thank you
Show LessQuestion:
IRSM005-301MHTR H-Bridge
- can it be used as a ON/Off switch (no PWM inputs),
It looks like the Vboot is generated from PWM at the Output.
My application is for ON time=20 Seconds Off time >+ infinity
I.E. it needs to operate as a SPST switch 20 Sec 'ON' 20 Sec 'OFF' than all output are tristated .
please advise.
Show LessHi everyone,
I have a question related to the EVAL-M3-IM564, in the user manual it says that the input voltage is from 165V to 265V, but in my project i will need to have an input of 110V 60Hz or 220V 50Hz.
1 - What changes would i need to make to the eval circuit to be able to use both 110V 60Hz and 220V 50Hz?
2 - What would be the implication on the output power?
3 - Would i need to change configurations for the motors, or only PFC?
Best Regards,
Paulo
Show LessHello everyone,
I am having problems related to sensing current and controling current limits using a induction Motor.
This post is related to my previous post: Motor Current Register in iMotion - Infineon Developer Community, but since i didn't get reply's for some time i am starting a new post.
I am controling the motor using voltage control, and i followed this aplication note: Induction motor control by iMOTION™ (infineon.com) I think the control of the motor is good, and im changing the speed using duty-cycle control.
But in my aplication i need to be able to limit the current that the gate can draw.
When i was testing the evaluation board i had used MotorLim, and putting diferent values would have an effect on the motor current. But now, in my custom board nothing happens, even if i put 150% or 50%, the current is allways the same.
My aplication requires another safety measure, that is to allow the motor current to go above a treshold only for a few ms before giving an error. For that i am using the Script in MCEWizard. In that script i want to use the MotorCurrent, since it should already be in RMS. But what when i read that register in MCE Designer or by UART i always get a very variable value.
When i tested in the evaluation board i would get the RMS value as expected:
Print taken in MCE designer with evaluation boards, the current value is in RMS.
Print taken in MCE designer with custom board, the current value is very variable.
What can cause this problems i am experiencing?
If someone can help i would apreciate it.
Best Regards,
Paulo
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Hi,
I am evaluating the REF-MHA50WIMI111T board and I am attempting to use an low cost off the shelf isolated USB to TTL interface to connect to the target board. The interface uses an FDTI FT232RNL chip. It has isolated data and power. I do not connect the Vcc of the interface to the target board. Only Txd, Rxd, and Gnd. It is able to connect and program my configuration and even start motor motion, but It seems to lose connectivity often and at random. I would prefer not to have to buy the Link interface that is specified as it seems to have features I don't need. The device I am using is found here:
https://www.amazon.com/dp/B07TS3GPQ1
I have it jumper configured for 3.3V operation and I verified with a scope that the TX signal levels are at 3.3V. It also seems to loop back on itself fine. I am connected to my desktop USB port via a 6 foot USB extender cable so that the interface is located very close to the target board. Is there any thing I can do to use this or some other low cost interface to work with this board?
Regards,
Mark
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