| 摘要 |
The invention concerns a transmitter circuit comprising a light source ( 20 ) and arranged to operate said light source ( 20 ) to transmit optical communication signals in response to balanced electric input signals from a first ( 11 ) and a second ( 12 ) circuit point. The transmitter circuit comprises a first ( 21 ) and a second ( 22 ) circuit branch which extend from said first ( 11 ) and second ( 12 ) points, respectively. The light source ( 20 ) is connected between the circuit branches ( 21, 22 ). The components which are positioned on the circuit branches ( 21, 22 ) are selected such that the transmitter circuit is formed with a symmetry which is such that, under normal operation conditions, a balanced drive voltage is the case between the connection points ( 13, 15 ) of the light source ( 20 ) on the circuit branches ( 21, 22 ) and such that the modulation current which drives the light source ( 20 ) essentially only depends on the voltage difference between said connection points ( 13, 15 ). The invention also concerns a communication system which comprises such a transmitter circuit. |
