MSP-EXP432P401R Current draw in LPM3 and LPM4

keepcoding

I have been playing around with the low-power modes on the new MSP-EXP432P401R Launchpad, but can't figure out a way to bring the current drain down to the specified < 1uA in LPM3/4. I can't get it below 12 uA.

I have disconnected all jumpers and measure the current drain across the 3V jumper. The device is powered via USB. The JTAG switch is in the position for the external debugger.

My code is pretty trivial:

MAP_WDT_A_holdTimer(); 
P1DIR  = 0xff; P1OUT  = 0x00; P1SEL0  = 0; P1SEL1  = 0; P1IFG = 0;
P2DIR  = 0xff; P2OUT  = 0x00; P2SEL0  = 0; P2SEL1  = 0; P2IFG = 0;
P3DIR  = 0xff; P3OUT  = 0x00; P3SEL0  = 0; P3SEL1  = 0; P3IFG = 0;
P4DIR  = 0xff; P4OUT  = 0x00; P4SEL0  = 0; P4SEL1  = 0; P4IFG = 0;
P5DIR  = 0xff; P5OUT  = 0x00; P5SEL0  = 0; P5SEL1  = 0; P5IFG = 0;
P6DIR  = 0xff; P6OUT  = 0x00; P6SEL0  = 0; P6SEL1  = 0; P6IFG = 0;
P7DIR  = 0xff; P7OUT  = 0x00; P7SEL0  = 0; P7SEL1  = 0;
P8DIR  = 0xff; P8OUT  = 0x00; P8SEL0  = 0; P8SEL1  = 0;
P9DIR  = 0xff; P9OUT  = 0x00; P9SEL0  = 0; P9SEL1  = 0;
P10DIR = 0xff; P10OUT = 0x00; P10SEL0 = 0; P10SEL1 = 0;
PJDIR  = 0xff; PJOUT  = 0x00; PJSEL0  = 0x30; PJSEL1  = 0; 
MAP_RTC_C_holdClock(); 
MAP_PCM_gotoLPM3();

Did I miss something? How can I get the current drain down to sub micro-amps?

Thanks in advance.

over 10 years ago

0 Luis RC over 10 years ago

TI__Genius 16840 points

Hi R,

Try using the same configuration shown in the datasheet. The one thing probably consuming more current is the SVS configuration, so you can try:
MAP_PSS_disableHighSide();
MAP_PSS_disableLowSide();

Regards,
Luis R

0 Dung Dang over 10 years ago

TI__Genius 17802 points

R,
in addition to trying out Luis' suggestion, you can compare your code with this existing code example, which completely covers the device configuration to achieve sub-uA in LPM3, :
dev.ti.com/tirex
~Dung

0 keepcoding over 10 years ago in reply to Luis RC

Intellectual 480 points

Thanks a lot! I think this did the trick: 1.2 uA, close enough to the specs in the datasheet.

0 keepcoding over 10 years ago in reply to Dung Dang

Intellectual 480 points

Thanks for the link, will have a look at this example as well.

0 Prem over 9 years ago in reply to Luis RC

Prodigy 60 points

Is it necessary to enable both high side and low side after exiting low power mode?

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MSP-EXP432P401R Current draw in LPM3 and LPM4