A CMOS biomedical preamplifier for portable skin surface Electromyograph (EMG) signal recording is presented. The bioamplifier includes an improved pseudoresistor for realizing a large time constant high-pass filter, an improved differential difference amplifier (DDA) for increasing bandwidth efficiency and a modified MOSFET floating resistor using linearized native NMOS transistors to enable low-pass filter design in reduced supply environment. By incorporating chopper stabilization, an input-referred noise of 2.76 μVrms is attainable for bandwidth of 1.5 kHz. The simulation results are based on BSIM3 models from TSMC 0.25 μm CMOS technology at dual supply of ± 1.5V. The proposed EMG amplifier permits fully integration, with a power consumption of 685 μW (without including power of micropower oscillator).