OPTO-ELECTRONIC TRANSCONDUCTORS

摘要

PCT No. PCT/GB94/00386 Sec. 371 Date Aug. 24, 1995 Sec. 102(e) Date Aug. 24, 1995 PCT Filed Feb. 25, 1994 PCT Pub. No. WO94/19867 PCT Pub. Date Sep. 1, 1994A transconductance device particularly suitable for use as a high frequency active filter has an input stage including at least one field effect transistor (M1) arranged to drive a laser diode (LD1) and an output stage including at least one photodiode (PD1) optically coupled to the laser diode. The output stage is preferably provided with a high impedance bias current supply circuit. In an alternative arrangement particularly useful as an operational amplifier, a differential input stage includes a pair of laser diodes (LD1 and LD2) optically coupled to respective photodiodes (PD1 and PD2) connected in series, the output being taken from the junction of the two photodiodes.