Patent ID: 6965722
Filing Date: 2005-11-15
Classification: G02F

Abstract:
1. An active matching electro-optic transducer driver circuit comprising the following: a data input terminal configured to carry data to be asserted on an electro-optic transducer coupled to the electro-optic transducer driver; a first bipolar transistor having a base terminal coupled to the data input terminal; a high voltage rail configured to carry a supply voltage during operation; a first resistor having a first terminal coupled to the high voltage rail, and a second terminal coupled to a collector terminal of the first bipolar transistor; a second bipolar transistor having a base terminal coupled to the second terminal of the first resistor, and a collector terminal coupled to the high voltage rail; a second resistor having a first terminal coupled to an emitter terminal of the second bipolar transistor; a third bipolar transistor having a collector terminal that is coupled to a base terminal of the third bipolar transistor and being configured to be AC coupled to the electro-optic transducer, the third bipolar transistor further having an emitter terminal coupled to a second terminal of the second resistor; a field effect transistor having a source terminal at least indirectly coupled to the high voltage rail, and a drain terminal at least indirectly coupled to the collector terminal of the third bipolar transistor; a fourth bipolar transistor having a collector terminal coupled to the collector terminal of the third bipolar transistor, and having a base terminal coupled to the data input terminal; a modulation current source coupled to an emitter terminal of the fourth bipolar transistor so as to draw current from the emitter terminal of the fourth bipolar transistor; and an operational amplifier having a first input terminal coupled to the first terminal of the second resistor, having a second input terminal coupled to the second terminal of the second resistor, and having an output terminal coupled to a gate terminal of the field effect transistor.