Low-noise, high-dynamic-range readout circuits with reduced power dissipation for capacitive sensors having small sensing capacitance and low transducer sensitivity are provided by combining a mixed modulation clock and a dual-chopper amplifier (DCA) circuit. The mixed modulation clock is generated by an exclusive-OR (XOR) of a high frequency clock and a low frequency clock. With the mixed modulation clock, an input signal is double-modulated by the high frequency clock and the low frequency clock, respectively. The DCA amplifies the input signal in two amplification stages. The first amplification stage amplifies the double-modulated signal and then demodulates the amplified signal by the high-frequency clock. Then, the second amplification stage amplifies the signal as a conventional chopper amplifier with the low-frequency clock as the chopping clock. Low pass filters following the two amplification stages filter out the modulated circuit offset and low-frequency flicker noise.