300 Series Low-Noise Matched Transistor Arrays The THAT 300 Series Low-Noise Matched Transistor Arrays are large geometry, 4-transistor, monolithic NPN arrays. These Low-Noise Matched Transistor Arrays exhibit both high speed and low noise, with excellent parameter matching between transistors of the same gender. The THAT 300 Series Low-Noise Matched Transistor Arrays are ideally suited for low-noise amplifier input stages, log amplifiers, and many other applications.