9.4.3 Clock Mode

Operate the ADC with an external clock or with the internal oscillator. For external clock operation, apply the clock signal to CLKIN. The ADC detects the presence of the external clock and selects the clock automatically. As described in Table 9, the clock frequency depends on the data rate used. Be sure the external clock is free of overshoot and glitches. A source-termination resistor placed at the clock buffer often helps reduce overshoot. For internal clock operation, connect CLKIN to DGND. Be aware of the accuracy of the internal oscillator as described in the Electrical Characteristics table. The internal oscillator begins operating immediately at device power-on. Read the CLOCK bit in the STATUS0 register to verify the clock mode.