The ISL28156 is a micropower precision operational amplifier optimized for single supply operation at 5V and can be operated down to 2. 4V. This device features an Input Range Enhancement Circuit (IREC), which enables it to maintain CMRR performance for input voltages greater than the positive supply. The input signal is capable of swinging 0. 5V above a 5. 0V supply (0. 25V for a 2. 5V supply) and to within 10mV from ground. The output operation is rail-to-rail. The 1/f corner of the voltage noise spectrum is at 1kHz. This results in low frequency noise performance, which can only be found on devices with an order of magnitude higher than the supply current. The ISL28156 can be operated from one lithium cell or two Ni-Cd batteries. The input range includes both positive and negative rail. The output swings to both rails.