Common mode feedback circuit supporting dual data rate, programmable gain amplifier having the same, and image sensor having the programmable gain amplifier

A programmable gain amplifier comprising:

• a differential input unit;
• a gain stage connected to the differential input unit;
• and
• a common mode feedback circuit connected to the gain stage,
• wherein the common mode feedback circuit comprises:
• a first capacitor connected between a common mode feedback terminal and a first output terminal;
• a second capacitor connected between the common mode feedback terminal and a second output terminal;
• a first cell having a third capacitor sharing charges with the first capacitor and a fourth capacitor sharing charges with the second capacitor, in response to a first clock control signal;
• and
• a second cell having a fifth capacitor sharing charges with the first capacitor and a sixth capacitor sharing charges with the second capacitor, in response to a second clock control signal.

An image sensor comprising:

• a pixel array arrayed in a predetermined color pattern;
• a programmable gain amplifier having a differential input unit, a gain stage connected to the differential input unit, and a common mode feedback circuit connected to the gain stage;
• and
• an analog-to-digital converter converting an amplified analog signal from the programmable gain amplifier to a digital signal,
• wherein the common mode feedback circuit of the programmable gain amplifier comprises:
• a first capacitor connected between a common mode feedback terminal and a first output terminal;
• a second capacitor connected between the common mode feedback terminal and a second output terminal;
• a first cell having a third capacitor sharing charges with the first capacitor and a fourth capacitor sharing charges with the second capacitor, in response to a first clock control signal;
• and
• a second cell having a fifth capacitor sharing charges with the first capacitor and a sixth capacitor sharing charges with the second capacitor, in response to a second clock control signal.