Optical S/PDIF Output

This little circuit is intended to be used to provide external access to an unused digital output of a CD or DVD drive in a PC. It provides an electrically isolated interface. In addition, this circuit is also handy for connecting a (portable) MD recorder, since these devices usually only have optical digital inputs.The circuit is a standard application for the Toshiba Toslink transmitter module. On account of the large amount of interference present in the PC environment, extra decoupling for the transmitter module is provided by L1, C1 and C2.

Resistor:
R1 = 8kΩ2
Capacitors:
C1 = 100nF ceramic
C2 = 10µF 63V radial
Inductor:
L1 = 47µH
Semiconductor:
IC1 = TOTX173 (Toshiba) (Eurodis)
Miscellaneous:
K1 = 4-pin SIL-header
K2 = 2-pin SIL-header