Power management

Posted on March 21, 2018 at 10:37Hi,I have question about maximum modulation index in motor control library. When it is 100% is there any danger at very low RPM high side driver's bootstrap capacitors to be completely discharged? Is there any mechanism which guarantee that low side of the half bridge will be switched on in predefined interval of time?#modulation-index #motor-control-library

Posted on March 01, 2018 at 13:31We are using L6203 IC in production with annual consumption of 400 Nos. The product where it is used in biomedical instrument used for blood analysis and diagnosis. IC L6203 is used for controlling temp of peltier from 3 set poins (25,30 and 37 �C) and temp can be changed to any values either 25,30,37 �C from its earlier set value ( either heating or cooling )Temp is sensed using LM35 temp sensor and using analog circuitry it is assigned to EN, IN1 and IN2 pin of L6203 to achieve set temp.Attached schematics and in design, D6(red) is indication of heating and D7 is indication of cooling.As per our observation when it is heating , D6 (red) is glowing.when is is cooling , D7(green) is glowing.But after stabilizing temp to set value, 4 conditions are observed  ( only D6 is ON, only D7 is ON, Both LED ON, Both LED OFF ), but temp is controlled correctly as per provided settings.So please guide us 'why LED indication is different when set temp is achie

Posted on February 21, 2018 at 14:10Hi renard.benoitPlease let me know the potential consequences of connecting a fan motor (Max 100W) to the A1 terminal of T435-800T (BT138-V marked on schematics) Triac? On the right schematics, please find my intended operation.Thanking you,Nazmulnull

Posted on March 13, 2018 at 18:21HelloI am looking for an equivalent of the mosfet stp5nk50z to 220  for a Rolling shutter, thank you

Posted on March 14, 2018 at 16:29Hello,I am looking for the MTBF Report of FIT value for the following part: SM30T21AYThank you for your help!

Posted on March 14, 2018 at 23:20Hi,I want to build my own application based on the X-Cube-SPN8 BLDC motor control expansion package.I can't find the CubeMX .ioc files in this package. However this would be very helpful as a starting point.I also checked out the X-Cube-SPN7 where the CubeMX .ioc files are included.Any idea where the .ioc files for the X-Cube-SPN8 could be found?Thank you,Marco#bldc-motor-control #motor-control

Posted on March 13, 2018 at 11:46I want to design Qi wireless receiver with 7.5W output capacity. I will use device STWLC03JR.Can anyone suggest me compact designing criteria or specification for Induction coil.I have seen they are readily available from mouser and Digikey. I want to select as per 7.5W capacity.Share me link for such compact induction coil.

Posted on March 09, 2018 at 14:05Hello,we tried to communicate to the powerstep01 trough spi and with a baudrate of 500kHz everythink works fine.The problem occur if we set the baudrate above 500kHz. Then we lose the first bit of each byte.For example:   - send 0xFF to the powerstep01 ABS_POS and we receive as result 0x7F   - send 0x1FF to the powerstep01 ABS_POS and we receive as result 0x17FIn the manual description is a max Value of 5MHz defined.Somebody help me if i overlooked something or there have to be specific timing issues.

Posted on February 16, 2018 at 16:50Hello!I am facing a problem with ST1S14. Conditions: - if Vin is 24.5V or less and load current less 30mA, output voltage drops to about 15V. (Problem)- If Vin becomes about 16V and less and load current still less 30mA, ->Vout=Vin-2VHowever if load >40mA output voltage behavior is ok: If Vin is 24.5V and more, output voltage is stable 22V - If Vin gets <24.5V, the output voltage get less but always Vout=Vin-2V, what is fully ok.  Seems when Vin comes to a level that Duty Cycles reaches it maximum and there is no load condition DCDC can't maintain proper Vout.Interesting that it happen when Vout>20V because when I made Vout=18V DCDC worked properly in full load and Vin range with the same schematic(just resistor divider is different)I tried to change 22uH to 10uH and 100uF. No resultTried to change Cout from 100uF(electrilytic) to 2x100uF(electrolytic), 10uF electrolyt

Posted on March 08, 2018 at 14:09Anyone could comment on why for UC3842B design, the MOSFET and Isolation transformer gets hot . We have done all calculation as per the design theory calculations. Thanks!

Posted on September 12, 2017 at 12:02 Hello everyone, We are having an issue with STC3115 (fuel gauge) where we are charging our device while it is powered off. After powering on the device, SoC received from STC3115 driver to application shows the same value as it was before charging. Then it takes around 30 minutes or so SoC slowly update to the actual value. Also to be noted that: a) If the battery is re-attached, then SoC shows the correct value on first power on after charging b) When the device is turned off (standby), our application sets fuel gauge to power saving mode c) SoC is updated correctly when the device charged while being powered on d) Our hardware does not support charging mode where the device could be woken from standby if the charger is connected If anyone has faced similar problems or have any ideas how to solve this issue with SoC not updating if the device is charged while powered off, please let us know. We are also happy to give more details if neede

Posted on February 27, 2018 at 14:19Start-up failure FOC SDK Hello!I used STM32F103C8 + STEVAL-IP05F and I was able to run successfully.Now, I developed my PCB, in which I took STM32F072C8 and STGIPQ3H60T-HZ.  I used FOC4.3.When I try to start, after running a speed ramp, I always get a Start-up error. I did everything that is described in FOC FAQ, but the error has remained. I reduce very strongly the coefficient of G2 to 1000 otherwise I get the erro Speed feedback.I got oscillograms when I overclocked the motor and I think they are normal. I observe that after several starts the engine is very hot. It seems to me that the FOC does not correctly calculate the current valuesThank you very much,Artem

Posted on February 22, 2018 at 07:59spice model for SCT10N120 for simulation in multism

Posted on February 15, 2018 at 09:13Hello,I am trying to monitor the h bridge VNH7100BAS. I want to open HSA and LSB during a certain time then open LSA and LSB. But I do not succeed to do it. I use the tab 'Input A,B' and try to control the H-Bridge with but it does not work.How can I do it ?Thanks for your help!#h-bridge #control #use

Posted on February 26, 2018 at 15:16L6472 stepper driver.hello, we are using 4x L6472 driver chip on a single board for some time now. We used the internal 16MHz clock, but it appeared that the clock frequencies differ a lot from each other. According the specs it can be plus or minus 3%. With four motors running simultaneously, it looks a bit funny to see them running different speeds/s. So what we did is using an external clock source. This clock is generated by the attiny, so is only available after the tiny is up and running. This worked for a coupe of days.now my question; this morning we blew up ( housing cracked open) 3 of the 4 L6470 while programming the Attiny. And we want to know why that happened? Also the boot diodes of three L6472 fried. Is this because the L6472 needs a clock before it can handle the init strings via SPI? I cannot find anything in the spect about the external clock and/or/if it must be present before the L6472 receives serial data?Or, is there an o

Posted on July 01, 2015 at 17:24Hello, I was at Embedded world Germany and an Italian ST representative showed me encoderless motor control which even worked well with zero speed (using High Frequency Injection). I want to test if this works in my case. Therfor I'm looking for a good Development board which will work with HFI and preferable a Cortex microcontroller. Which one do you recommend? Kind Regards, Dik-Jan

Posted on February 23, 2018 at 18:44Hi there,I would like to create a custom PCB build around the STSPIN32F0 MCU which integrates a gate driver and some other fancy features.Now I need to know some specs of that driver but they're not listed in the Datasheet (or am I blind ? Maybe ...).I need to know the resistance of the driver output for calculating if my MOSFETS will work with the driver ...So what are the values for R_src and R_snk  ?Next thing I would like to know: I can't find a Power rating of the driver. Only thing that's mentioned in the datasheet is the 600mW of output current (sink / source).Can anyone help me or point me into the right direction ?Other solutions for calculating, wether my mosfets work are also welcome.Thank you in advance.#gate-driver #stspin32f0 #mosfet

Posted on February 01, 2018 at 14:15Hello!Our company recieved from the official dealer in our country the TDA7850EP chip. The seller claims that this is an improved version of the TDA7850, but we never heard about. Is it so?I did not find information about this chip on your site. Where can I get its datasheet and description?Sorry for the trouble and thank you in advance.Yours faithfully,Aleksandr Efremov

Posted on February 18, 2018 at 20:33Hi all,i try to run the SPINFamily Evaluation Tool with my Nucleo-F401RE + IHM03A1 Expantion Board.If i try to connect to the board, the sowftare returns me an 'Communication board initialization failed' error message. I did a firmeware update of the nucleo and i connected all nessesary parts. Whats wrong?Do i need a binary for the nucleo to get the communication to work?In the serial spy tool i can see this HEX code (maybe this is helpful):01040000 00000081 81010000 00000000 00000000 00000000 00000000 00000000 B8A073DA B8A073DAB1A91DD2 0F03E879 98111875 1B03D079 1B03D079 B1A96AA5best regardsmerle

Posted on November 08, 2017 at 14:43I wonder if the schematic suitable to apply the FOC library? And what settings should I change for it?

Posted on February 05, 2018 at 14:13       Hello, I got a problem with my light dimmer pet project using ST's snubberless triac, T435-800T. It's working fine (turning on and off based on the control input) with the positive going half cycle of AC main. But during negative going half cycle, I found a strange behavior. Traic failed to turn off  during the negative going half cycle of AC main. I tried two separate rated incandescent lamp as a load. One rated at 25 W and another 60 W. What I found are, for 25 W lamp, turning off of Triac during negative half cycle not working at random intervals (please find the attachment) and for 60 W lamp, there is no turning off of Triac during negative going pulse. Please be noted that I checked control signal for both cased, and controller producing exact signal as the positive going half cycle. Can you please share your experience if I got same problem earlier? Do I need a Triac with higher Irms (on-state) value to overcome

Posted on February 19, 2018 at 09:43Hello ST,I am a NEW hire in our company and I am trying to understand the Analog PFC in our current design using L4981A PFC controller IC. I need to fully understand the feedback control portion in this circuit because we are having some input current oscillation problems (Dancing waveform that is non-sinusoidal).I am referring to the L4981A's application note for help. You can access it in this link: http://www.st.com/content/ccc/resource/technical/document/application_note/94/6e/ec/8c/4c/3e/40/a9/CD00003936.pdf/files/CD00003936.pdf/jcr:content/translations/en.CD00003936.pdfWe have plans to move into TI products especially thehttp://www.ti.com/product/UCD3138AIC family of digital PFC solutions.My questions below are related to how to select compensation network values for the inner current loop of Boost PFC.Doubts from pages 7,8 & 9The equation below is trying to say that the inductor down slope must be smaller than the ramp up s

Posted on July 08, 2016 at 09:59Hello, may anybody can help me out with a  .schLib and .pcbLib for the ST PowerStep01   89-PowerVQFN in Altium Designer? May send via EMail? Thanks so far Best Regards Oliver #powerstep01-stepper-motor-driver

Posted on January 29, 2018 at 00:26Hello everybody,                              I am trying to understand the calculations and derivations of L4981A average current mode PFC controller circuits from the application note, AN628 : DESIGNING A HIGH POWER FACTOR SWITCHING PREREGULATOR WITH THE L4981 CONTINUOUS MODE.1) How was rms switch current found from O/P power and Peak inductor voltage?2) Similarly how to find the RMS diode current?How do the factors 3) The AC component of diode current flows into the output capacitor soHow to derive Ic?4) RMS twice capacitor line frequency capacitor currentWhat is the difference between Total RMS-Capcitor Current and RMS twice line frequency capacitor current?Does it refer to output bulk capacitor or input capacitor?Why is 2f twice line frequency capacitor current important?5) RMS high frequ

Posted on January 31, 2018 at 10:30 Hi, I'm using IHMOA03 to control NEMA23 format stepper motor running in half-step current controlled clock step mode. I put the scope on the sense resistor R1 to monitor the phase current and it is not what I expected. The motor is a six wire connection with the centre taps left unconnected: series full coil connection. The pulse rate is circa 1kHz and vertical scale is 0.2V/div ( R1 is 0R1 ) . The wave is smoothed because R/L corresponds to about 625Hz ( 1 ohm / 1.6mH ) that's fine but I was expecting a symmetric waveform not this abrupt cut off. Each winding should go through a cycle 0 70 100 70 0 -70 -100 -70 0 % ; ie a symmetrical cycle. Why am I not seeing this? Slower speeds show the step nature but there is still this asymmetric switching. What is this about? thanks.