A 2- $\mu\text{W}$ 45-nV/√Hz Readout Front End With Multiple-Chopping Active-High-Pass Ripple Reduction Loop and Pseudofeedback DC Servo Loop
A 1.8 $\mu$ W 60 nV$/\surd$ Hz Capacitively-Coupled Chopper Instrumentation Amplifier in 65 nm CMOS for Wireless Sensor Nodes