摘要 |
A circuit is disclosed for use in optical fiber data communication systems which is compatible with TTL digital input signals and which drives a light emitting diode (LED) coupled to an optical fiber transmission link. A pulse shaping network is provided to couple current from a constant current source to energize the LED or to a bank of open collector NAND gates controlled by the input digital signal such that the current may be selectively shunted around the LED. |