Saturation detector for an ADC

1. A saturation detector for a cascaded ΔΣ ADC, the saturation detector comprising:

a magnitude square unit for receiving an output of the cascaded ΔΣ ADC, determining a magnitude of the output, and squaring the magnitude;

an adder for receiving an output of the magnitude square unit and providing a sum output as a saturation signal;

a filter for filtering the saturation signal and outputting a filtered saturation signal;

an amplifier for amplifying the filtered saturation signal and providing an amplified, filtered saturation signal to the adder; and

a comparator for comparing the saturation signal to a threshold and determining whether the cascaded ΔΣ ADC is in saturation.

2. The saturation detector of claim 1 , wherein the threshold is programmable.

3. The saturation detector of claim 1 , wherein the filter includes a leaky bucket filter.

4. The saturation detector of claim 1 , wherein the filter includes a first order, low pass filter.

5. A method for detecting saturation in a cascaded ΔΣ ADC, the method comprising:

receiving an output of the cascaded ΔΣ ADC;

determining a magnitude of the output;

squaring the magnitude;

adding the squared magnitude to a feedback signal and outputting a sum that represents a saturation signal;

filtering the saturation signal and outputting a filtered saturation signal;

amplifying the filtered saturation signal and providing the amplified, filtered saturation signal as the feedback signal; and

comparing the saturation signal to a threshold to determine whether the cascaded ΔΣ ADC is in saturation.