Low-Frequency Noise Measurements of Bipolar Devices Under High DC Current Density: Whether Transimpedance or Voltage Amplifiers

Different setups for the measurement of the low-frequency noise of semiconductor devices have been proposed in the literature, based on the use of either low-noise voltage amplifiers (VAs) or, more recently, transimpedance amplifiers (TAs). This paper aims to address the applicability and physical limit of each configuration, when they are applied to measure the LF noise of HBTs or diodes at moderate to high DC current densities. Extracted noise curves issued from different setups are analyzed. Noise data collected from recent low-noise technologies shows that physical limits are being systematically approached