Part Number:MSP430F6733A
Hi!
In some conditions, the AUXVCC1 pin consumes more than specified in datasheet: parameter "Current drawn from highest supply": 0.73uA.
AUXVCC1 is connected to battery thru diode. AUXVCC2 is connected to DVCC and configured as an interrupt source if DVCC becomes less than 3.02V.
My customer prefomed 2 tests, with different voltages at AUXVCC1.
In each test, the DVCC was raised to a voltage of 3.5V, and then lowered below AUXVCC1.
When the AUXVCC1-DVCC difference is reached around 30-80mV, the AUXVCC1 pin starts consuming more (1.2 and 2.12 μA) than specified in the datasheet (0.73 μA Max).
In second test AUXVCC1 is connected to battery thru 2 diodes to change voltage.
During all 5 test steps, there is no switching between power supplies.
Step | DVCC, V | AUXVCC1, V | IAUXVCC1, uA |
1 | 3,3000 | 3,4 | 0,40 |
2 | 3,5000 | 3,4 | 0,05 |
3 | 3,4000 | 3,4 | 0,42 |
4 | 3,3200 | 3,4 | 2,12 |
5 | 3,3190 | 3,4 | 0,38 |
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Connected additional diode to AUXVCC1 | |||
Step | DVCC, V | AUXVCC1, V | IAUXVCC1, uA |
1 | 3,3000 | 3,24 | 0,14 |
2 | 3,5000 | 3,24 | 0,04 |
3 | 3,2000 | 3,23 | 0,40 |
4 | 3,1000 | 3,13 | 1,20 |
5 | 3,0900 | 3,18 | 0,37 |
Initialization:
//_______________________________________________________________________PMM //_errata_PMM26 SFRRPCR |= SYSNMI; // threshold for switching from DVCC to AUX21 1,95V, threshold for reset by core voltage 1,8V PMMCTL0_H = PMMPW_H; // open PMM for write PMMRIE = 0; // remove reset on core voltage PMMCTL1 = 0; // not used SVSMIO = 0; // not used PM5CTL0 = 0;// not used //___1,95В SVSMHCTL = SVSHE | SVMHE | SVSMHRRL1; // enable SVSH and SVMH | level SVMH = 1,95В while (!(PMMIFG & SVSMHDLYIFG)); // waiting while SVMH is setting // disable SVSML SVSMLCTL = 0; while ((!(PMMIFG & SVSMLDLYIFG)) && ((--timeout) > 0)); // waiting while SVML is setting + timeout PMMIFG = 0; // clear all flags //__Vcore PMMCTL0_L = PMMCOREV_0; // set Vcore = 1,42V (AM)/1,54V (LPM) PMMCTL0_H = 0x00; // close PMM registers for write //_errata_PMM26 SFRRPCR &= ~SYSNMI; //_______________________________________________________________________AUX AUXCTL0 = AUXKEY | LOCKAUX; // key for write | AUX lock AUXCTL1 = AUX1MD | AUX1OK;// AUX1 controlled by software | AUX1 state - normal AUXCTL2 = AUXMR_0 | AUX0LVL_6 | AUX2LVL_6; // monitoring alltime | switching DVCC when VCC > 3,02В | supply error signaling if AUX2 < 3,02V AUX2CHCTL = AUXCHKEY; // disable charging on AUX2 AUX3CHCTL = AUXCHKEY; // disable charging on AUX3 AUXADCCTL = 0; // ADC is not measure aux supply AUXIFG = 0; // clear flags AUXIE = AUX1SWIE | AUX2DRPIE; // enable interrupt on AUX1 | AUX2 below 3,02B AUXCTL0 = AUXKEY; // unlock AUX AUXCTL0_H = 0x00; // close AUX regs for write
Please help to solve problem with hi consumption.