SBASAM0A March 2024 – June 2024 ADS127L18
ADVANCE INFORMATION
The ADC provides an internal oscillator for use as the ADC clock. Because of the associated high level of clock jitter, the internal oscillator is only recommended for measuring dc signals. Operate the ADC with an external clock signal for measuring ac signals. In SPI programming mode, default operation is the internal oscillator. In the hardware programming mode, external clock operation is fixed. Because the internal oscillator frequency is 25.6MHz, program the ADC clock divider to configure the ADC clock frequency corresponding to the speed mode.
The internal oscillator is only available through SPI programming. When changing the clock mode from an external clock to the internal oscillator, maintain the external clock after changing the clock mode. Maintain the clock mode for at least four cycles after the SPI register write command that changed the clock mode completes. After the clock mode changes, the ADC ignores the control inputs (the START and RESET pins) for a period of 150μs. This period of time allows the internal oscillator to stabilize.