In this paper we describe an efficient and robust digital implementation of a lock‐in amplifier, based on the classic quadrature technique and on a mathematical algorithm for error signal extraction. Both the hardware and the software architecture are modular. The hardware consists of a VME‐bus (IEEE 1014) standard crate, in which commercial VME boards (the CPU, the ADC and DAC) are housed. The software is written in standard C language for portability and easy integration also within complicated software architectures. The software algorithm implementing the lock‐in amplifier can be particularized by the user on the basis of the needed performances and on the available hardware. Numerical and experimental tests on a lock‐in amplifier prototype have shown that it performs as theoretically predicted. The limit of our prototype (50 kHz maximum sampling rate for 16 bit resolution) depends only on the hardware used, and it is not the present technological limit.
High-performance modular digital lock-in amplifier
BARONE, Fabrizio;
1995-01-01
Abstract
In this paper we describe an efficient and robust digital implementation of a lock‐in amplifier, based on the classic quadrature technique and on a mathematical algorithm for error signal extraction. Both the hardware and the software architecture are modular. The hardware consists of a VME‐bus (IEEE 1014) standard crate, in which commercial VME boards (the CPU, the ADC and DAC) are housed. The software is written in standard C language for portability and easy integration also within complicated software architectures. The software algorithm implementing the lock‐in amplifier can be particularized by the user on the basis of the needed performances and on the available hardware. Numerical and experimental tests on a lock‐in amplifier prototype have shown that it performs as theoretically predicted. The limit of our prototype (50 kHz maximum sampling rate for 16 bit resolution) depends only on the hardware used, and it is not the present technological limit.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
