The utility model relates to the technical field of
microphone circuits, and discloses an earphone
microphone amplifying circuit for internal communication. Comprising a link socket J4, a
resistor R47, a
resistor R51, a
coupling capacitor C36, a
resistor R54, a
capacitor C62, an
operational amplifier chip U1A, a
coupling capacitor C46, a resistor R86, a capacitor C61, a selection channel ESWS3, a resistor R63, a resistor R50, a resistor R59, a capacitor C60, a resistor R49, a field tube Q11, a
coupling capacitor C33, a resistor R48, a resistor R57, a coupling capacitor C4, a
triode Q23, a resistor R52, a resistor R85 and a capacitor C41. According to the invention, the influence of external interference on sound signals is reduced, sound
distortion and
noise are effectively reduced, and the definition and accuracy of internal communication are improved; compared with the prior art, the circuit provided by the utility model enhances the amplification capability of weak signals, improves the communication reliability, is simple and reasonable in structure, reduces the use of unnecessary elements, reduces the cost and
power consumption, improves the stability of the circuit, and provides an earphone
microphone amplification solution with better performance for an internal communication
system.