Patent ID: 6229398
Filing Date: 2001-05-08
Classification: H03F

Abstract:
An interface device for use between an optoelectronic sensor and a load, the impedance of which is lower than that of the sensor, the said interface device comprising an impedance adaptation stage, wherein the adaptation stage comprises a distributed amplifier with a broad band of frequencies, the input of which is directly connected to a terminal of the sensor, and constitutes an impedance with an ohmic value which is greater than that of the load, and the output of which is connected to the load, and wherein the interface device additionally comprising a bootstrap which comprises a field-effect transistor mounted in a common drain, the gate of which is connected to one terminal of the sensor, and the source of which is connected to the other terminal of the sensor, via a capacitor with a selected value, which makes it possible to reduce the noise factor of an optical connection which uses the said sensor, whilst maintaining a high, flat level of gain in a very broad frequency band ranging from a few kHz to a few GHz, whereas the bootstrap can compensate for the undesirable effects of the parasitic capacitor of the sensor.