Impedance matched transmission circuit with analog-to-digital converter
An impedance matching transmission circuit for a transducer has a transmission medium connected to the transducer. A transmitting circuit is connected to the transmission medium with the transmitting circuit terminating in a reference circuit element. The transmitting circuit comprises an analog to digital converter having an analog input connected to the reference circuit element, and having a digital output. A digital to analog converter receives the digital output and generates an analog output signal in response thereto. A driver circuit is connected to the transmission medium and receives the analog output signal and supplies a driver signal to the transmission medium.
1. An impedance matching transmission circuit for a transducer, said circuit comprising:
a transmission medium connected to the transducer;
a transmitting circuit connected to the transmission medium, said transmitting circuit terminating in a reference circuit element;
wherein the transmitting circuit comprising:
an analog to digital converter having an analog input connected to the reference circuit element, and having a digital output;
a digital to analog converter for receiving the digital output and for generating an analog output signal in response thereto; and
a driver circuit connected to the transmission medium and for receiving the analog output signal and for supplying a driver signal to the transmission medium;
wherein said analog to digital converter outputs an encoded digital signal; and
wherein said analog to digital converter comprises a plurality of comparators, comparing an output signal from the reference circuit element with an output signal from a plurality of reference impedances.
2. The circuit of claim 1 wherein each of said plurality of comparators has a first input connected to the reference circuit element and a second input connected to a reference impedance.
3. The circuit of claim 2 wherein each of said plurality of comparators has an output, and said analog to digital converter further comprises a digital encoder connected to the output of said plurality of comparators and for generating an encoded digital signal in response.
4. The circuit of claim 1 wherein said reference circuit element is a resistor.
5. The circuit of claim 1 wherein said transmission medium is an ultrasound cable.