CCS/MSP430G2553: What is the minimum DCO frequency that can be used for msp430g2553 controllers

Tool/software: Code Composer Studio

Hi,

I am using msp430 controller to log temperature values to SD card every 15 minutes. I am using  msp430g2553 controller without LDO & external crystal as to save power. In between logging, I am putting the controller in the low power mode (LPM3) which uses VLO as clock source. But the issues is VLO is very much dependent on the voltage (Li-ion battery changes voltage from 4.2V to 3.6V) and temperature, hence we are not able to log 15 minutes precisely. So I am planning to use DCO clock source, as it is much more accurate than VLO.

To save power, I am planning to run DCO well below 1MHz, but one TI workshop document is saying we can't go beyond 1 MHz (pasted below). But MSP430x2xxx family user guide is showing we can use 100 KHz frequency also (pasted graph below). Please advice.

Regards,