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Tool/software: Code Composer Studio
Dear,
I'm using MSP-EX430FR5994 development kit and running at MCLK=16MHz (internal DCO oscillator is used), with one FRAM wait state (since frequency is higher than 8MHz). I have initialized and enabled 4 SPI masters (SMCLK = 1MHz), 1 SPI slave and DMA controller with 5 channels enabled.
I have measured power consumption (current) in active mode at the 3.3V rail (on J101 header, only GND jumper presented) and value measured by ampermeter is 7.5mA, wich is 3 times higher than it is stated in MSP430FR5994 datasheet (values presented in datasheet are typical, and there are no information about maximal values, but anyway measured current is much higher than those typical values).
Do you have any recomendadtion how to decrease power consumption?
What should be power consumption in LPM0 and LPM1 modes (I have to enter low power mode, where SPIs and DMA are still active and CPU clock is off)?
Is it possible to power the micro controller with 1.8V, with laboratory power supply for example?
Thank you in advance,
Stevan
Hi Stevan,
Stevan Marinkovic13 said:I have measured power consumption (current) in active mode at the 3.3V rail (on J101 header, only GND jumper presented) and value measured by ampermeter is 7.5mA, wich is 3 times higher than it is stated in MSP430FR5994 datasheet (values presented in datasheet are typical, and there are no information about maximal values, but anyway measured current is much higher than those typical values).
Do you have any recomendadtion how to decrease power consumption?
I'd recommend following the recommendations in Section 2.4 in the MSP-EXP430FR5994 User's Guide. Specifically, disabling the back-channel UART and configuring the inputs/outputs to ensure none are floating. Also, it's important how you measure the current consumption. Since you're using an ammeter, I'd recommend using the EnergyTrace++ feature in CCS instead to obtain more accurate results.
Stevan Marinkovic13 said:What should be power consumption in LPM0 and LPM1 modes (I have to enter low power mode, where SPIs and DMA are still active and CPU clock is off)?
For these modes, the typical values can be found in Section 5.6 in the datasheet. However, these values are assuming that no I/O's are sourcing/sinking any current. You can add the active current consumption values given for the SPI (see Section 5.10) module to find the overall expected current consumption. Table 6-1 has an excellent summary comparing current consumption values for each mode.
Stevan Marinkovic13 said:Is it possible to power the micro controller with 1.8V, with laboratory power supply for example?
Yes, according to Section 5.3 in the datasheet, the MSP430FR5994 can be powered by 1.8V.
Regards,
James
MSP Customer Applications
Hi James,
Thank you very much for the inputs.
I have one additional question:
I'm reffering to MSP430FE599x datasheet:
What about 1.8V power supply?
I tried to apply 1.8V from the laboratory power supply, but MSP-EXP430FR5994 board doesn't work. It looks for me that board starts working when applied voltage is higher than 2.2V, which is indicative for me, together with the upper table.
Thanks,
Stevan
Hi Stevan,
As mentioned by Footnote 1 on the first page of the datasheet, the actual minimum supply voltage is restricted by SVS levels. The specific values are provided in Table 5-2 in the datasheet. The value of 1.8V is given, since it's in between the min and max values.
Using the MSP-EXP430FR5994, I programmed the device with the 'msp430fr599x_lpm4-5_02.c' code example in CCS Resource Explorer. Then, after removing all the isolation jumpers that connect to the onboard emulator, I connected the LaunchPad to an external power supply via the "3V3" and "GND" pins. For this code example, the device is looking for a low-to-high signal on P1.3, which will trigger the LED to blink. I just used a jumper wire connected to the "3V3" pin and touched P1.3.
First, I started at a supply voltage of 1.80V, but touching P1.3 didn't cause the LED to blink. After disconnecting from the power supply, slightly increasing the supply voltage, reconnecting, and repeating this process, I got the LED to blink at a supply voltage equal to 1.88V (keep in mind this was the value shown on the display and not measured from a multimeter). Looking at Table 5-2, 1.88V is the typical value where the Power Management Module (PMM) releases the BOR reset (as shown in Figure 2-3 in the User's Guide). On other devices, they could start operating at 1.77V or up to 1.99V.
Hopefully, this makes sense.
Regards,
James
MSP Customer Applications
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