Really Need Both Current-LNA and Voltage-LNA to Measure LF Noise?
Application Notes
Turnkey Solution for LF Noise Measurement
Keysight E4727B (Advanced Low-Frequency Noise Analyzer; A-LFNA) allows you to measure the LF (Low Frequency) noise of semiconductor devices very easily. The E4727B consists of hardware and software. The user can measure LF noise by just entering the expected measurement conditions and then the software will then set all parameters of custom hardware optimally. The most important and critical component in the hardware is LNA (Low Noise Amplifier) and very small noise and very high gain performances are required. The LNA in E4727B is designed to cover all device’s measurements and all measurement conditions. Some commercial system is using both Voltage-LNA and Current-LNA for LF noise measurement, but this application note explains why the Voltage-LNA is enough in E4727B.