CMOS imager with discharge path to suppress reset noise

An image sensor comprising:

• a photo-detector;
• a reset contact electrically connected to the photo-detector;
• a discharge path that enables charge flow between the reset contact and the photo-detector;
• and
• a reset implant electrically connected to the reset contact and to the photo-detector.

A method for resetting an image sensor that substantially avoids reset noise, the method comprising:

• applying a first reset voltage level to a reset contact of the image sensor;
• and
• creating a discharge path between the reset contact and a photo-detector having a charge in response to the application of the first reset voltage;
• transferring the charge on the photo-detector through the discharge path;
• increasing the voltage on the reset contact to a second reset voltage level;
• establishing a potential difference across the discharge path in response to the second reset voltage level;
• and
• reducing the second reset voltage on the reset contact at a rate sufficient to maintain the potential difference across the discharge path that prevents the discharge path from collapsing before the charge on the photo-detector is substantially removed.

An image sensor comprising:

• a photo-detector;
• a reset contact electrically connected to the photo-detector;
• means for enabling charge flow between the reset contact and the photo-detector;
• and
• a reset implant electrically connected to the reset contact and to the photo-detector.

A system for resetting an image sensor that substantially avoids reset noise, the method comprising:

• means for applying a first reset voltage level to a reset contact of the image sensor;
• and
• means for creating a discharge path between the reset contact and a photo-detector having a charge in response to the application of the first reset voltage;
• means for transferring the charge on the photo-detector through the discharge path;
• means for increasing the voltage on the reset contact to a second reset voltage level;
• means for establishing a potential difference across the discharge path in response to the second reset voltage level;
• and
• means for reducing the second reset voltage on the reset contact at a rate sufficient to maintain the potential difference across the discharge path that prevents the discharge path from collapsing before the charge on the photo-detector is substantially removed.