ADA4528-x has a low voltage noise density of 5.6nV/√Hz. Placing a 1KΩ resistor
with thermal noise of 4nV/√Hz at the input of the amplifier increases total
input referred noise to 6.9nV/√Hz. It is important to use low value resistors
around a low noise amplifier. With a low source resistance, the amplifier
voltage noise dominates. As source resistance increases, the resistor thermal
noise increases. As the source resistance further increases (>100KΩ), amplifier
current noise becomes the main contributor of the total input noise.