Schaltungsanordnung zum Ansteuern eines optischen Sendeelements

摘要

The invention relates to circuit arrangement for operation of an optical transmitter in an integrated-services broadband transmission system with devices for the transmission of narrowband and broadband signals between subscribers and an exchange via an optical waveguide system, with a biasing current feed-in device controlled by a control amplifier and a driver amplifier to amplify the narrowband signals, where the devices required for broadband operation can be de-activated to operate the optical transmitter for narrowband-only operation. According to the invention, the modulation of the driver current for the optical transmitter is carried out through modulation of the biasing current by means of the output power of the narrowband driver amplifier. The modulation of the biasing current is initiated in inexpensive fashion via a coupling capacitor at the base of the current source transistor, at the base of which the output of the control amplifier is also connected via a protective resistor.