CHARGE TRANSFER DEVICE

PURPOSE:To expand a dynamic range obtained by a holding circuit by setting the threshold voltage of a reset transistor which is coupled to the output end of a charge transfer unit to a value smaller than that of each switching transistor forming the charge transfer unit, thereby enhancing in advance the data voltage value introduced to a sample-holding circuit from the charge transfer unit. CONSTITUTION:The input terminal a point, to which an input voltage VIN is applied, is connected as an input circuit 1 to the point b of an input capacity CIN through an MOS type input transistor TIN, a plurality of MOS type switching transistors TS1-TSN and bucket capacities CB1-CBN are formed at the charge transfer unit 2 of rear stage, and connected in cascade. Further, sample- holding circuit 3 having transistors F1 and F2, F3 and F4, F5 and F6 connected in series with each other at the rear stage is connected to the rear stage. In this structure, a reset transistor TR is provided between the transfer unit 2 and the circuit 3, and the threshold voltage is selected to a value smaller than that of each transistor of the transfer unit 2.