Switched capacitor filter systems and methods

An image detector system comprising:

• an image detector;
• a logic device;
• a switched capacitor filter configured to receive a reference signal and provide a sampled and filtered reference signal for the image detector, wherein the switched capacitor filter comprises:
• a first switch, having a first switch terminal and a second switch terminal, configured to receive the reference signal at the first switch terminal;
• a first capacitor, having a first terminal coupled to the second switch terminal and a second terminal coupled to a reference voltage, configured to sample the reference signal provided via the first switch, under control of the logic device, and store a sampled reference signal;
• a second switch having a third switch terminal and a fourth switch terminal, with the third switch terminal coupled to the first terminal of the first capacitor;
• and
• a second capacitor, having a first terminal coupled to the fourth switch terminal and a second terminal coupled to a second reference voltage, configured to be connected to the first capacitor by the second switch, under control of the logic device with the first switch open, to store the sampled and filtered reference signal, wherein with the second switch open the sampled and filtered reference signal is provided by the second capacitor for the image detector;
• a third switch, coupled between the first switch terminal and the first terminal of the second capacitor and under control of the logic device, configured to provide a direct path to bypass the switched capacitor filter and receive the reference signal and provide the reference signal as the sampled and filtered reference signal to the image detector;
• and
• a fourth switch, coupled between the third switch and the first terminal of the second capacitor and under control of the logic device, configured to pre-charge the second capacitor with the reference signal if the third switch and the fourth switch are closed.

A method of providing a sampled and filtered reference signal to an image detector array, the method comprising:

• receiving a reference signal;
• sampling the reference signal with a first capacitor to store a sampled reference signal based on the reference signal;
• coupling a second capacitor to the first capacitor to share charge stored on the first and second capacitors to generate the sampled and filtered reference signal to store on the second capacitor;
• decoupling the second capacitor from the first capacitor, wherein the sampled and filtered reference signal is stored on the second capacitor to provide for one or more image detectors within the image detector array;
• providing a direct path configured to bypass the second capacitor and receive the reference signal and provide the reference signal as the sampled and filtered reference signal to the image detector array;
• and
• coupling the second capacitor to the direct path to pre-charge only the second capacitor with the reference signal if the direct path is providing the reference signal as the sampled and filtered reference signal to the image detector array.