The present application provides a
noise suppression circuit, an isolation decoder, a
chip and an electronic device, wherein the
noise suppression circuit includes: a differential
operational amplifier circuit for gaining an input differential
signal; a first filter circuit, whose input end is connected to the output end of the
operational amplifier circuit, for filtering the
signal after gaining the
operational amplifier circuit, and outputting a first frequency
signal; a second filter circuit, whose input end is connected to the output end of the operational
amplifier circuit, for filtering the signal after gaining the operational
amplifier circuit, and outputting a second frequency signal; a third filter circuit, whose input end is respectively connected to the output end of the first filter circuit and the output end of the second filter circuit, for further filtering the first frequency signal and the second frequency signal to remove excess
noise and unnecessary frequency components, and output a
pulse width modulation signal. The present application can improve
signal quality and anti-interference ability.