Power management

Posted on April 11, 2017 at 07:21I am using LD1085  voltage regulator connected to a 500mA of load. When the capacitor connected is 100uF at both i/p and o/p it is becoming too hot within  30-50 sec. Same is the condition with 10uFcapacitor at i/p and o/p and also with 22uF at i/p and 47uFa

Posted on April 11, 2017 at 07:19Please reply me as soon as possible.

Posted on April 07, 2017 at 08:26Hi ,I followed the link http://www.st.com/content/st_com/zh/products/evaluation-tools/product-evaluation-tools/automotive-ic-eval-boards/eval-l9907.html  and imitate the L9907 schematic to create my own PCB pad ,using the same components .But it did not work out. Testing finds out that L9907 chip dose not run ,the VDD pin shows only 0.8mV ,which supposes to be 3.3V.Meanwhile ,the boost converter seems not to work too.Could someone give me some advice on where the errors might be exist ?Thank you.Yours Bruce

Posted on April 04, 2017 at 17:25/********* This question is also asked at ''Power Management and Motor Control > Discussions'' *********/Hi,I am trying to use the STEVAL-PCC009V2 & EVAL6470H boards using the SPINFamily Evaluation Tool (Version 3.2)However when I try to connect to the board I get the following error:I have managed to locate the below hex file at the following location:C:\Program Files (x86)\STMicroelectronics\SPINFamily Evaluation Tool 3.2\Firmware

Posted on March 30, 2017 at 02:33Alternate Method to Characterize Stepper Motor for Voltage Mode Drivers Application note AN4144 describes a procedure to characterize the stepper motor for use with their voltage mode driver such as the L6470. This procedure starts from knowledge of the stepper motor (either from published values or measurements), creates an initial solution. Then a current probe is attached to one of the windings and the current through the winding is observed during a slow acceleration of the motor. This data is used to perturb the existing solution in an attempt to make the current consistent during the acceleration profile. The procedure can work fairly well, but there are several problems: It is not always obvious how to adjust the parameters to get the desired response.As the motor accelerates, the windings are heating up so the current decreases.The motor parameters must be known or measu

Posted on March 24, 2017 at 13:35Hi,I have downloaded the PSpice model of the VIPer17HD and when I try to simulate with Orcad 16.3, It gives and error: ERROR -- Invalid device in subcircuit.This error is repeated for each line in the .lib.How can I solve it?Thanks#error #viper17 #pspice

Posted on March 20, 2017 at 20:21Trying to communicate to a X-Nucleo IHM11M1 demo board and the Nucleo-F401RE using Tera Term and the IHM11M1 does NOT respond to sent commands.  I am running the X-Cube-SPN11 software sucessfully by uploading it to the IHM11M1.  I can manually start the BLDC motor using the on-board buttons on the -F401RE board.  When I start the terminal emulator SW to communicate to the IHM11M1/F401RE demo boards, I get no response from the demo boards.  NOTE, when I press the reset button on the F401RE, the menu screen apprears in the terminal emulator window as shown below:  ********************************************************************************             X-NUCLEO-IHM11M1 - 6-Step Motor Control Expansion board        *****************************************************************

Posted on March 23, 2017 at 13:11What is the 'Admin mode' of the the STPM3x Evaluation Software for ?What is the password ?Any help is greatly appreciated.

Posted on March 22, 2017 at 14:35Hello everybody,I'm working on a power supply with a LLC Stage in it. The LLC has following specifications:Uin: 385VUout: 28VIout: 5.75ASwitching Frequency: 300kHzFor the secondary side rectification I want to use a SRK2000A but i have the Problem with a delayed Turn-off of the synchronous rectifier MOSFet's. My selected Turn_off_threshold is 25mV. In the attached Picture you can see in yellow the output of the SRK2000A in red the secondary current in blue the Vds over the MOSFET and in green the resonant current. My schematic is like in the Datasheet but with RD=2kohm. At the High output current of 5.5A the time between the SRK2000A turns off the MOSFET and the current in the MOSFET gets negative is only about 40ns. So there is only a little margin to current reversal. Has anybody an idea to get a smaller delay? Or would it be better if i use a SRK2001?I'm grateful for any

Posted on February 21, 2017 at 07:02Hi all. I need a help regarding I2C write operation on one of the register of STC3100. There are two configurable registers, one is 'Mode register' and other is 'Control register'.I noticed that writing to the Control register is not working. When I write a value on control register, lets say 0x12 or any value,and then whenever I try to read that register it gives value as 0x10 everytime. Could you explain why it is happening so?

Posted on March 20, 2017 at 23:15I have a sensorless BLDC drive application where I need to get near 100% duty cycle on the power PWM while spinning at about 1300Hz (21 pole pairs, 3700RPM).  However it appears that the six-step library only samples the BEMF during the off time, thus precluding the use of 100% duty cycle on the PWM.  Here are my questions.1) How much off time is required to sense the BEMF? Or how close to 100% duty cycle can I get using this method?2) Do you have another library I can use that does not have this duty cycle limitation?3) I don't need FOC, but if it would work in my application I am open to it.  Would your FOC library run at 1300Hz or faster with a low inductance motor?Thanks,Tim#duty-cycle #six-step #pwm #bemf

Posted on March 10, 2017 at 14:31Hi would it be possible to use STSPIN3201 to build BLDC servo drive.Basic spec step and direction input, quad encoder input. Any help greatly appreciated. Thanks Paul

Posted on March 14, 2017 at 17:05 when the stepper motor got horizontal forces the powerstep01shutdown and all the status register bits turns to zeros.We work in current mode, the thresholds levels adjusted to maximum.

Posted on March 15, 2017 at 08:171�what is Vsense_nom ? How level? I find nothing in datasheet.

Posted on March 09, 2017 at 15:28Hi, i designed transformerless capacitive power supply for compact home automation project. Initially its used for only controlling load so it worked good at 4.8Vdc. Later i added seven segment display and tactile switch for HMI, once all circuit construction done at breadboard then i checked voltage it drops from 4.8V to 4.1V. This is due to current demand while adding more component i understand that. But i seen some reference from ST, MICROCHIP, NXP they were used this power supply in energy meter design and this circuit will have adc, display, keypad, communication circuit. Is there any special consideration has to be follow to get correct voltage regulation?.Application Note : AN1476 from STM

Posted on February 17, 2017 at 06:01In the document EVLCMB1-90WADP, is L2 a simple inductor or a transformer? If it is a transformer, then what is the turns ratio?

Posted on February 21, 2017 at 07:11Hello,I am looking at using the L6480 in the externally supplied modes, where my system will be supplying: VS = +24V DCVSREG/VCC = +12VVCCREG/VREG = +3.3VThe +24V supplied to VS by the system is removed (floating) during an emergency stop condition.Can the L6480 handle this situation where VS and thus VBOOT is removed, but the other rails are still supplied with the +12V and +3.3V respectively?On page 34 of the data sheet there is a note that states 'VSREG must be always less than VBOOT in order to avoid related ESD protection diode turnon'When VS is removed due to an emergency stop condition, VSREG will be +12V greater than VBOOT (floating), causing the internal protection diode turnon.It goes on to say 'The device can be protected from this event by adding an external low drop diode between the VSREG and VS pins' 

Posted on February 28, 2017 at 15:54i am looking at using the L6668 as a multy output flyback, i need it to have a high voltage start up (which this IC does have, that is good), but i also need it to synchronise it to about 100KHz from a micro.my question is, can the L6668 be synchronised ?. basically it needs to run at a fixed frequency and be synchronized by an external micro.

Posted on February 18, 2017 at 17:51I am using the L6615 in a 50V bus current sharing application and I have the required voltage divider from each side of the high side current sense resistor to ground but I am unsure if another series resistor needs to be placed in series with the sense pins on the IC.  Any guides on how to calculate these values would be appreciated.  Thanks!

Posted on February 13, 2017 at 20:46I want to use the STM6600 controller to manage the power ON/OFF of my microcontroller system. In the specific I want:- Turn ON the system simply pushing a button.- Turn OFF the system simply pushing the same button.- Force the power OFF pushing and holding the same button.I read at pg. 5 on the STM6600 http://www.st.com/content/ccc/resource/technical/document/datasheet/1f/9e/3b/43/ec/04/44/71/CD00226957.pdf/files/CD00226957.pdf/jcr:content/translations/en.CD00226957.pdf that'By a long push of one button (#PB) or two buttons (#PB and #SR) either a reset is asserted or power for the application is disabled depending on the option used.'It says th

Posted on February 10, 2017 at 15:10HiI'm using the L6472 Eval board, revision 1.1.We got two L6472 Eval board connected to our main stm32f2 board. Both drivers are running smoothly and everything is working, but reading the absolute position register makes no sense.  The absolute register seems to have some faulty bits, which is hardwired to 0.  I'm using the c driver which weremade by ST. (dspin.c)When reading the absolute position register (called ABS_POS in the datasheet) is in 2's complement format and it ranges from -2^21 to +2^21-1.  I'm using the dspin.c driver to read this value (see below) but I do not get the correct value.  I'v also got the new L6472 DISC eval board and tryed it via windows and here the ABS_POS seems to work.I'm currently moving the motor without checking if my position is correct. However due to safety reason I need toknown the

Posted on February 08, 2017 at 15:03Hello,i our Motor Control Board with FOC i have very high losses in the Driver IC L6230Q in the VFQFPN package.In the On-Time of the High side i have a differenz of 2.6V between the Operatine Voltage (21V) and the Output Voltage on the Motorphase. (see picture)Channel 2 (blue) = Opperating VoltageChannel 1 (yellow) = Out 2measured direktly on the pins of the L230One of the other Phase is Low (Low-Side On) and the third one is Open (EN is low)With the thermo camera i can see hot points (>100°C) in the chip. so there is no bad soldering.The schematic is equal to the datasheet.With the P-Nucleo IHM001 i dont have this high losses. On this Board the L6230Q is in the big PowerSO36 PackageAnyone ideas?Thank YouEric

Posted on June 08, 2016 at 11:29Hello All,i have a question about the VND7140AJ-E which i have incorperated into a design of our company. I read the datasheet several times, because the maximum current of the chip is not really stated as such, just as ''internally limited''. So i checked the Iliml and Ilimh parameters and they stated 4Atyp and 12Atyp. I need 4A max, so this should be more than enough for my application. The chip also has a maximum voltage of 28V which is enough for my 24V usage. We assembled the boards and I put it on the testbench. But to my surprise i can't get more than 1Amp out of it. I have been trying to figure out what is wrong, so I took off all the components which are around the VND7140 and i put the dutycycle on the input to 100%. Still just 1A.Another thing i noticed while the VND7140 was on the board is that when i lowered the dutycycle it would go on for a second and then drop int

Posted on January 13, 2017 at 02:26I am having difficulty discerning information from the datasheet.1) Where can I find additional information on this IC? (Other than the OrCad Model and Application Sheet.)2) What voltage can be used to activate/trip the H-Bridge gate to turn on the MOSFETs? Page 7/Tbl 3 of the DS states that the maximum gate/source voltage is 18v. But, Page 8/Tbl 5 of the DS states that the Gate Threshold Voltage is between 2v; minimum and 4v; maximum. Is it that the gate will definitely be tripped above 4v, but you should not exceed feeding it more than 18v?2) It appears that the Temp Sensor supply voltage is less than the gates?Per page 10, of the DS, the Chain Forward Voltage of the sensor is between 3.72v and 4.04v. If the Temp Sensor can only handle 4.04v, and I want to drive a PIC controller with 5v (this is typical, for the chip,) I guess I could add a separat

Posted on February 05, 2017 at 10:46We are using microcontroller STM32F051r8t6 for one of our application. We are currently working on power inverter using microcontroller. To drive MOSFET bridge we are generating PWM signals which are given to MOSFET driver. The problem we are facing is  that the MOSFETS burns out when the mains ON when charging pulses given. As the MOSFETs burns out driver also gets affected which inturns affect microcontroller. May be we are missing some consideration while coding, So can any one please suggest some solution for this.  To generate PWM signal we are using TIMER1 in PWM mode 1 and PWM mode 2. Channel 1 and 2 iof TIMER1 are  used in PWM Mode 1 and Channel 3 and 4 are used in PWM Mode 2.  There are two modes Discharging and Charging. -> In Discharging Mode the PWM wave is generated on all four channels by giving sample values of sine wave in Capture Compare Regist