| 摘要 |
PURPOSE:To realize an A/D converter which is very small-sized and has a high resolution and a high conversion speed by providing plural rows of charge transfer devices, which are different in value of storage gate capacity, in parallel and charging the electric charge repeatedly to generate an accurate reference voltage in a high speed. CONSTITUTION:A primed signal electric charge is sent to a sample holding buffer 111 provided for each vertical signal line or every several vertical signal lines at least and is compared with a reference voltage. The signal sent to a comparing part in this manner is compared with the reference voltage, and a high-1evel voltage (or pulse) is outputted to a signal line 112 when the reference voltage crosses the signal voltage. Signal lines 118, 119, 120, and 121 correspond to (00), (01), and (11) respectively. For example, when the high-level voltage is outputted to the signal line 112 in the process of determination of upper two bits, it is transmitted to a signal line 120 through a gate 116, and signal (1,0) is sent to the output side. simultaneously, a signal 121 is fixed to the low level by a gate 126, and therefore, the signal is not transmitted to the signal line 121 even if a gate 117 is opened. |
