A circuit for low-noise reference signal generation comprising a filter unit and a functional unit. The filter unit comprises a transistor and an energy storage component. The transistor comprises a first node, a second node, a control node and a body node. The first node is configured to receive an input signal. The second node is configured to output a filtered signal. The control node is configured to receive a control signal for controlling the transistor to turn on or off. The body node is configured to couple to the input signal, the output signal or a signal which is similar to the input signal or the output signal. The energy storage component is coupled to the second node of the transistor. The functional unit is coupled to the second node of the transistor and the energy storage component. The functional unit has high input impedance.