A signal generator (100, 1100, 1300) for generating an output signal (S_OUT) according to an oscillating signal (XO_IN), comprising: a plurality of edge sampling circuits (102_1-102_N), each configured to receive the oscillating signal (XO_IN), sample the oscillating signal (XO_IN) to obtain at least one of a rising edge and a falling edge in one cycle of the oscillating signal (XO_IN), and output a sampled signal (S1-SN) using the at least one of the rising edge and the falling edge; and an edge combining circuit (104, 600, 800, 1000), configured to combine a plurality of sampled signals (S1-SN) generated by the edge sampling circuits (102_1-102_N), respectively, to generate the output signal (S_OUT), characterized in that the edge sampling circuits (102_1-102_N) comprise at least a first edge sampling circuit and a second edge sampling circuit, and the signal generator further comprises: a voltage generator, configured to generate and supply a first reference voltage to the first edge sampling circuit and generate and supply a second reference voltage to the second edge sampling circuit; wherein the first reference voltage is different from the second reference voltage, the first edge sampling circuit obtains a first set of a rising edge and a falling edge in a cycle of the oscillating signal according to the first reference voltage, the second edge sampling circuit obtains a second set of a rising edge and a falling edge in the cycle of the oscillating signal (XO_IN) according to the second reference voltage, and the first set of the rising edge and the falling edge is different from the second set of the rising edge and the falling edge. a plurality of edge sampling circuits (102_1-102_N), each configured to receive the oscillating signal (XO_IN), sample the oscillating signal (XO_IN) to obtain at least one of a rising edge and a falling edge in one cycle of the oscillating signal (XO_IN), and output a sampled signal (S1-SN) using the at least one of the rising edge and the falling edge; and an edge combining circuit (104, 600, 800, 1000), configured to combine a plurality of sampled signals (S1-SN) generated by the edge sampling circuits (102_1-102_N), respectively, to generate the output signal (S_OUT), characterized in that the edge sampling circuits (102_1-102_N) comprise at least a first edge sampling circuit and a second edge sampling circuit, and the signal generator further comprises: a voltage generator, configured to generate and supply a first reference voltage to the first edge sampling circuit and generate and supply a second reference voltage to the second edge sampling circuit; wherein the first reference voltage is different from the second reference voltage, the first edge sampling circuit obtains a first set of a rising edge and a falling edge in a cycle of the oscillating signal according to the first reference voltage, the second edge sampling circuit obtains a second set of a rising edge and a falling edge in the cycle of the oscillating signal (XO_IN) according to the second reference voltage, and the first set of the rising edge and the falling edge is different from the second set of the rising edge and the falling edge. a voltage generator, configured to generate and supply a first reference voltage to the first edge sampling circuit and generate and supply a second reference voltage to the second edge sampling circuit; wherein the first reference voltage is different from the second reference voltage, the first edge sampling circuit obtains a first set of a rising edge and a falling edge in a cycle of the oscillating signal according to the first reference voltage, the second edge sampling circuit obtains a second set of a rising edge and a falling edge in the cycle of the oscillating signal (XO_IN) according to the second reference voltage, and the first set of the rising edge and the falling edge is different from the second set of the rising edge and the falling edge.