7.3.4 Clock Input

The AMC1336 system clock is provided externally at the CLKIN pin. The clock signal must be applied continuously for proper device operation.

To support the bipolar input voltage range with a unipolar high-side supply AVDD, the AMC1336 includes a charge pump. This charge pump stops operating if the clock signal is below the specified frequency range or if the signal is paused or missing. In that case, the input bias current increases beyond the specified range and significantly reduces the input resistance of the device. When the clock signal is paused or missing, the modulator stops the analog signal conversion and the digital output signal remains frozen in the last logic state. When the clock signal is applied again after a pause, the internal analog circuitry biasing must settle for proper device performance. In this case, consider the t_ASTART specification in the Table 10 table.