SLAZ210I October 2012 – May 2021 MSP430F438
ADC Module
Functional
Incorrect conversion result in extended sample mode
The ADC12 conversion result can be incorrect if the extended sample mode is selected (SHP = 0), the conversion clock is not the internal ADC12 oscillator (ADC12SSEL > 0), and one of the following two conditions is true:
- The extended sample input signal SHI is asynchronous to the clock source used for ADC12CLK and the undivided ADC12 input clock frequency exceeds 3.15 MHz.
or
- The extended sample input signal SHI is synchronous to the clock source used for ADC12CLK and the undivided ADC12 input clock frequency exceeds 6.3 MHz.
- Use the pulse sample mode (SHP = 1).
or
- Use the ADC12 internal oscillator as the ADC12 clock source.
or
- Limit the undivided ADC12 input clock frequency to 3.15 MHz.
or
- Use the same clock source (such as ACLK or SMCLK) to derive both SHI and ADC12CLK, to achieve synchronous operation, and also limit the undivided ADC12 input clock frequency to 6.3 MHz.