MSP430F6433 Power consumption > 32uA in LMP3 mode

Zhiyu,

Looking at your code, it is very similar tot he TI LPM3 example found in CCS TI Resource Explorer. You do take some additional steps to ensure ADC is off that is not entirely necessary for it is off by default after power-up. You also turn of the LDO properly by ensuring LDOEN == 0. My best guess here your increased power numbers are due to your GPIO configuration. In the TI examples we default the pin configuration to output low for we can guarantee on our target board that the pins have a "Open" connection on the headers. This would be the equivalent to cutting all unnecessary traces around the MSP430 on your board. You may have a point of contention on the board that can be causing the additional power usage. For example, if you have a trace on the board tied to VCC in some way (through another chip/resistors/caps or directly) and feed this to a GPIO, by forcing the pin on the chip side to output low, you effectively make a current sink that will consume more power. I would check your board and see if any of the GPIOs have a voltage when you go to LPM3.

Also, please follow the recommendations of other pins within Table 1-3 Connection of Unused Pins in the Family User Guide. www.ti.com/lit/slau208

Also please follow the ULP Advisor within CCS to help you lower your power numbers.

Hope this helps!

Regards,
JH

Zhiyu,

I updated the example code from CCS to what I included below. The current example code on CCS uses the USB monikers of the parent device and will need to be updated to what is below.  That being said, the code I tested below had 2uA max pull. When you are measuring your current, do you have the debugger connected?  If so, make sure to run the device in "Free Run" mode before taking measurements. Having the emulator active on the device will add significant current draw.

#include <msp430.h>

int main(void)
{
  WDTCTL = WDTPW + WDTHOLD;                 // Stop WDT
  // Enable XT1
  UCSCTL6 &= ~(XT1OFF);                     // XT1 On
  UCSCTL6 |= XCAP_3;                        // Internal load cap
  while(BAKCTL & LOCKBAK)                    // Unlock XT1 pins for operation
     BAKCTL &= ~(LOCKBAK);  
  do
  {
    UCSCTL7 &= ~(XT2OFFG + XT1LFOFFG + XT1HFOFFG + DCOFFG);
                                            // Clear XT2,XT1,DCO fault flags
    SFRIFG1 &= ~OFIFG;                      // Clear fault flags
  }while (SFRIFG1&OFIFG);                   // Test oscillator fault flag

  UCSCTL6 &= ~(XT1DRIVE_3);                 // Xtal is now stable, reduce drive
                                            // strength
  UCSCTL4 &= ~(SELA0 + SELA1 + SELA2);      // Ensure XT1 is ACLK source
  
  // Port Configuration
  P1OUT = 0x00;P2OUT = 0x00;P3OUT = 0x00;P4OUT = 0x00;P5OUT = 0x00;P6OUT = 0x00;
  P7OUT = 0x00;P8OUT = 0x00;P9OUT = 0x00;PJOUT = 0x00;
  P1DIR = 0xFF;P2DIR = 0xFF;P3DIR = 0xFF;P4DIR = 0xFF;P5DIR = 0xFF;P6DIR = 0xFF;
  P7DIR = 0xFF;P8DIR = 0xFF;P9DIR = 0xFF;PJDIR = 0xFF;

    // Disable VUSB LDO and SLDO

  LDOKEYID   =     LDOKEY;                 // set USB KEYandPID to 0x9628
                                            // enable access to USB config reg
  LDOPWRCTL &= ~(LDOEN);            // Disable the VUSB LDO and the SLDO
  LDOKEYID   =    0x9600;                  // disable access to USB config reg

  // Disable SVS
  PMMCTL0_H = PMMPW_H;                // PMM Password
  SVSMHCTL &= ~(SVMHE+SVSHE);         // Disable High side SVS 
  SVSMLCTL &= ~(SVMLE+SVSLE);         // Disable Low side SVS

  __bis_SR_register(LPM3_bits);       // Enter LPM3
  __no_operation();                         // For debugger
}