power consumption

[hsguja]

Posted on August 22, 2008 at 11:23

power consumption

[hsguja]

Posted on May 17, 2011 at 12:42

Hi,

I am using STM32 performance stick from hitex. I am trying to measure the power consumption for the BOARD and not CPU for a set of benchmark tasks. The hitex data sheets only provide maximum power dissipation value for the board which is 1.5W The power consumption value i get is 470mW in the active mode when the benchmark code is running. When the board is idle (program execution is over) the power consumption is 350mW. Is there any way i can verify if these values are correct or within accepted range. I have enabled USART2, GPIOA and running at 72MHz (HSE). thanks & regards Hemal

[16-32micros]

Posted on May 17, 2011 at 12:42

Hi,

You can ask an STM32-PerformanceStick Hitex Kit Expert here

http://www.ehitex.de/pr_frage.php?products_id=314&xID=5bd8fd2efb0a25c7434fd0e6199f2962

and let us know :) Cheers, STOne-32.

[hsguja]

Posted on May 17, 2011 at 12:42

Hi STOne-32,

thanks for the link, i got the response from Hitex. i have attached the complete emails below ----------------------------------------- Hi, I am using STM32 performance stick. I am trying to measure the power consumption for the BOARD and not CPU for a set of benchmark tasks. The hitex data sheets only provide maximum power dissipation value for the board which is 1.5W The power consumption value i get is 470mW in the active mode when the benchmark code is running. When the board is idle (program execution is over) the power consumption is 350mW. Is there any way i can verify if these values are correct or within accepted range. I have enabled USART2, GPIOA and running at 72MHz (HSE). thanks & regards Hemal ----------------------------------------- Hi Mr. Gujarathi, As I understand you correct you try to measure the power consumtion of the complete STM32-PerformanceStick device? To verify the data you have measured the only way is to cut an USB cable and measure the current directly in the line. The current mentioned in the data sheet is the all inclusive current the USB host have to provide to the Stick. If this current is not available from host side the enumeratin process is dicarded and the stick can not be used in this configuration. To get this value we have measured it in the line. This has nothing to do with the current of the STM32-Device. The power consumption which is displayed in the Dashboard GUI is the really measured current of the STM32 controller. Please have a look at the schematics (Run the Dashboard, menu Help and Schematics) on page 2 in the PDF file you'll see the schematic of the measuring unit in the upper right corner. The shunt resistors R400 and R401 combined with the FETs Q401 and Q402 are switched depending of the power consuption of the demo application. In normal mode the R400 (10 Ohm) is used for a range over 1 mA current. In the schematic there are 3 ADC lines going to the STR7. The current displayed in the Dashboard GUI is the Voltage difference measurend at the used resistor. Formula : 10 Ohm resistor STM32_Power_Consumption = Channel0 - Channel2; /* Delta */ STM32_Power_Consumption *= 330; /* factorize with 3.3 Volt*/ 10 KOhm resistor STM32_Power_Consumption = Channel1 - Channel2; /* Delta */ STM32_Power_Consumption /= 3; /* = 330/1000 */ The measurment failure is less than 1% in the average. Kind Regards, Stefan Grohmann ---------------------------------------------------------------- Hello Mr.Stefan Grohmann, Thank you for the information you provided. I would request you to clear some doubts that i had after readnig your mail. These might look quite simple questions but it is important for me to get them clarified. Yes it is correct that i am trying to measure the power consumption for complete STM32-PerformanceStick device. I am measuring the current in the similar way you mentioned below i.e i have cut the USB cable and placed a current meter in series with the stick and the PC (USB host). 1. STM32 device means complete performance stick with SPI, CAN, FLASH and io-board as well. STM32 controller means only STM32103RB chip, right?? 2. As per your information the dashboard shows the current consumption for the STM32 controller i.e. only the STM32103RB and not rest of the peripherals on board, right?? 3. The data sheet says maximum current consumption FOR STICK device is 300mA. When i execute the applications and measure the current i get values of around 140-145mA. Please note i have connected the extension board as well and using one of the GPIO lines. So can i say that these values are within expected range if not exact? Thanks again for your reply regards Hemal ----------------------------------------------------------------- > 1. STM32 device means complete performance stick with SPI, > CAN, FLASH and io-board as well. STM32 controller means only > STM32103RB chip, right?? Yes, indeed. But this means also the driven Ports of the STM32F103 chip > 2. As per your information the dashboard shows the current > consumption for the STM32 controller i.e. only the STM32103RB > and not rest of the peripherals on board, right?? There are no peripherals on the Stick. The current for the extension board Is directly suplied by the Vbus (USB) for 5V and the 3.3 volts of the line regulator on the stick. This current is not measured by the Dashboard application. > 3. The data sheet says maximum current consumption FOR STICK > device is 300mA. When i execute the applications and measure > the current i get values of around 140-145mA. Please note i > have connected the extension board as well and using one of > the GPIO lines. So can i say that these values are within > expected range if not exact? Yes I expect this current if only the view peripherals are used. Aprox. 25 mA for the UART phy, Aprox. 30 mA for the FTDI (on the Stick) Aprox. 10 mA for the LED (on the Stick) Aprox. 50 mA for the STR7 (on the Stick) Rest should be the STM32F103 (including the GPIO)