Charge amplifiers that can be implemented in thin film and are useful for imaging systems such as digital breast tomosynthesis with reduced x-ray exposure

An imaging system, comprising:

• a detector comprising a matrix of pixels, the matrix comprising N rows and M columns of pixels, each of a plurality of the pixels comprising:
• a circuit comprising:
• a p-i-n diode having a cathode of the p-i-n diode is coupled to a cathode bias voltage or ground;
• a charge transistor having a first source/drain terminal coupled to an anode of the p-i-n diode and a second source/drain terminal to the cathode of the p-i-n diode;
• a storage capacitor having a first terminal coupled to a second source/drain terminal of the charge transistor and a second terminal coupled to the cathode of the p-i-n diode;
• an amplification transistor having a gate terminal coupled to the first terminal of the storage capacitor and a first source/drain terminal coupled to a reference voltage in operation;
• a read transistor having a first source/drain terminal coupled to a second source/drain terminal of the amplification transistor;
• a data line having a first terminal coupled to a second source/drain terminal of the read transistor;
• and
• a readout circuit coupled to a second terminal of the data line and configured to provide in operation an output voltage corresponding to charge on the storage capacitor caused by interaction between the p-i-n diode and light.