Noise protection circuit for digital amplifier - has resistor between amplifier input and output with input resistor to set noise threshold

摘要

The noise protection circuit, for a digital amplifier, consists of a resistor (R2) which is connected between the input (E) and output (A) of the digital amplifier (S) which consists of t wo parallel-coupled stages. The voltage divider formed by this protective resistor and the amplifier input resistor (R1) is such that when a noise voltage is applied, the amplifier only switches to another state if that noise voltage exceeds a given level. The ration of the two resistors is equal to the ratio of the supply voltage to the magnitude of the data signal at the input of the amplifier.