The device uses one of the two internal
oscillators (low-power oscillator or high-speed oscillator) for converting the analog input
voltage into a digital output code.
The steps for selecting the oscillator and
setting the sampling speed are:
- Select the low-power oscillator
(OSC_SEL = 1b) to monitor slow-moving signals (< 300 Hz) at extremely low-power
consumption and sampling speeds (< 600 SPS). Select the high-speed oscillator
(OSC_SEL = 0b) to scan the sensor signals with faster sampling speed (> 50 kHz).
- Set the sampling speed by programming
the NCLK_SEL register:
Equation 2.
- fs = Sampling speed.
- Oscillator frequency = 1 /
tHSO or 1 / tLPO depending on the OSC_SEL bit; see the Section 6 section for 1 / tHSO or 1 / tLPO.
- nCLK is the number of clocks in one
conversion cycle (see the NCLK_SEL register).