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Frequently Asked Question

What is the ratio between the analog and digital currents drawn by the DDS devices?

Typically, the analog current is 10% to 30% of the total current when the device is running at the MAX System CLK rate. In some DDSs (AD9852/54), it also depends on which options or features are enabled (inverse SINC, amplitude scale factor, etc.). The analog current is mainly biasing current, therefore the current does not change much with the System CLK rate, unlike the digital current which is proportional to the System CLK rate. If the System CLK is quite low the analog current may dominate the total current.