Balanced regenerative charge detection circuit for semiconductor charge transfer devices
Sensing circuit for semiconductor charge transfer devices
Reduction of sparkle noise and mottling in CCD imagers
Low noise synchronous detection for a charge transfer device Patent #: 4644287
ApplicationNo. 07/100668 filed on 09/24/1987
US Classes:327/563, With differential amplifier327/212, With clock input330/253, Having field effect transistor377/63Charge-coupled device
ExaminersPrimary: Miller, Stanley D.
Assistant: Callahan, Timothy P.
Attorney, Agent or Firm
International ClassesH03K 3/00 (20060101)
H03K 3/356 (20060101)
H04N 5/217 (20060101)
AbstractA low 1/f noise amplifier has been provided for an output of a CCD imager. To reduce clock noise, the amplifier employs a differential detection scheme. Linear stages (54, 76) are coupled by capacitors (60, 82) to a differential amplifier (64). Differential amplifier (64) employs a first (112, 118) and a second (172, 198) differential transistor pair. The second differential pair (172, 198) is cross-coupled to the outputs of the first differential pair (112, 118) by load resistances (180, 206) with the voltage drop across them remaining substantially constant. To maintain stability, the positive and negative branches of the amplifier are periodically reset by a resetter (210). The input nodes (62, 86) are periodically reset to a voltage reference.