Full Integrated Biomedical Amplifier with Adjustable Gain and Bandwidth for ECG Recording

A new full integrated biomedical amplifier with adjustable gain and bandwidth for ECG recording were designed in 0.13 μm CMOS process. Designed circuits simulated in Star-Hspice2009. This bioamplifier is composed of two primary and secondary stage. Primary amplifier determines the system bandwidth. This amplifier has achieved low cutoff frequency below 1Hz by a pseudo -resistor. Pseudo resistors presented in the previous structures shows the ohmic value of about 109 in 0.13 μm CMOS process which is not enough to achieve 1Hz low cutoff frequency.a new pseudo resistor is proposed which shows a resistance of about 1013 ohm.Also the proposed pseudo resistor has the ability to properly tunable compared to previous structures.. The given low cutoff frequency varies from 0.008Hz t 1Hz. Amplifier high cutoff frequency is controllable with a proposed structure; high cutoff frequency of the primary amplifier is from 38Hz to 160Hz. Then, to enhance the whole amplifier gain, we designed a secondary amplifier Then, with changing the capacitor feedback in the secondary amplifier, we havetunable its gain. and finally a proper control is done over the biomedical amplifier gain and bandwidth. the input referred noise equals 2.4 μV and the gain of whole system is between 45.6 dB to 60 dB and the total power consumption of the amplifier is 550nW to 850 nW.