A 4.43 T Z_IN 0.0128 mm² Cascaded Instrumentation Amplifier with Input- biased Pseudo Resistor for Implantable Brain Machine Interfaces

A cascaded instrumentation amplifier (CaIA) with input- biased pseudo resistors (IBPR) is presented for implantable brain machine interfaces (BMI). The gain distribution of two-stage cascaded amplifiers, instead of a single-stage amplifier, helps to achieve an input impedance of 4.43T Omega at 100Hz, and maintain the small active area (0.0128 mm(2)). The input- biased pseudo resistors contribute to a much lower high-pass corner (f(HP)=0.00011Hz) compared with the conventional structure, the input-referred noise is only 3.836 mu Vrms integrated from 0.5Hz to 10kHz with 0.98 mu W power consumption.