Abstract: Embodiments of the present invention provide a device and a method for converting analog information, which achieve sufficient information spread of a sparse signal with a filter of relative low order and reduce hardware complexity, and which is not only applicable to processing of time domain sparse signals, but also applicable to processing of frequency domain signals. The method includes: multiplying an analog sparse signal with a random sequence to obtain a randomized analog sparse signal; performing IIR filtering to the randomized analog sparse signal to obtain an information spread random analog sparse signal; reducing a frequency of the information spread random sparse signal to obtain a frequency-reduced random analog sparse signal; and sampling the frequency-reduced random analog sparse signal with a low sampling rate to obtain a compressed sampled signal.