Pixel circuit

A pixel circuit, comprising:

• a photodiode (PD), arranged to accumulate charges in response to incident radiation, to generate a PD signal;
• a transmission circuit, coupled between the PD and an ordinary floating diffusion (FD) node, arranged to transmit the PD signal to the ordinary FD node;
• a reset circuit, coupled to the ordinary FD node, arranged to reset the ordinary FD node and provide a reference signal;
• a signal storage circuit, coupled to the ordinary FD node, arranged to store the PD signal on a specific node having a reduced leakage path in comparison with the ordinary FD node during a holding phase of the pixel circuit, wherein the holding phase is a time interval starting from a first time point at which the PD signal is stored on the specific node and ending at a second time point at which the pixel circuit is selected for performing a read-out operation;
• and
• a buffer circuit, coupled to the ordinary FD node, arranged to buffer pixel signals of the pixel circuit, to generate output signals for being read out when the pixel circuit is selected for performing the read-out operation, wherein the pixel signals comprise the PD signal and the reference signal.