1. A sensor circuit comprising:
a digital to analog (DA) comparison circuit comprising an analog sense current input, a digital input and a plurality of series-coupled resistors throuah which an analog sense current at the analog sense current input passes, the DA comparison circuit configured to generate first and second voltages responsive to respective nodes of the plurality of series-coupled resistors, to scale the second voltage responsive to a digital value at the digital input and to compare the scaled second voltage to the first voltage to generate a comparison signal; and
a control circuit configured to provide digital values to the digital input of the DA comparison circuit responsive to the comparison signal and to generate a digital output corresponding to the sense current.
2. A circuit according to claim 1, wherein the DA comparison circuit comprises:
a voltage generator circuit that generates a reference voltage and a variable voltage responsive to the sense current;
a scaling circuit that scales the variable voltage responsive to the digital value; and
a voltage comparator that generates the comparison signal responsive to a comparison of the scaled variable voltage and the reference voltage.
3. A circuit according to claim 2, wherein the scaling circuit comprises:
a plurality of resistors coupled in series between a node that develops the variable voltage and a signal ground node; and
a plurality of switches, respective ones of which are configured to bypass respective ones of the plurality of resistors responsive to respective bits of the digital value at the digital input.
4. A circuit according to claim 2, wherein the voltage generator circuit comprises a bandgap reference circuit.
5. A circuit according to claim 2, wherein the DA comparison circuit has a reference adjustment input, and wherein the voltage generator circuit is operative to adjust the reference voltage responsive to a digital value at the reference adjustment input.
6. A circuit according to claim 5, wherein the voltage generator circuit comprises:
a plurality of resistors coupled in series between a node that develops the reference voltage and a signal ground node; and
a plurality of switches, respective ones of which are configured to bypass respective ones of the plurality of resistors responsive to respective bits of the digital value at the reference adjustment input.
7. A circuit according to claim 2, wherein the voltage generator circuit comprises:
a first resistor connected between the sense current input and a node at which the variable voltage is developed;
a second resistor connected between the node at which the variable voltage is developed and a node at which the reference voltage is developed;
a bipolar transistor having its base terminal coupled to its collector terminal and a signal ground node; and
a third resistor connected between an emitter terminal of the bipolar transistor and the node at which the reference voltage is developed.
8. A circuit according to claim 7, wherein the third resistor comprises a plurality of resistors connected in series between the emitter terminal of the bipolar transistor and the node at which the variable voltage is developed, and wherein the voltage generator circuit further comprises a plurality of switches, respective ones of which are coupled in parallel with respective ones of the plurality of resistors.
9. A circuit according to claim 2, wherein the voltage generator circuit comprises:
a first resistor connected between the sense current input and a node at which the variable voltage is developed;
a second resistor connected between the node at which the variable voltage is developed and a node at which the reference voltage is developed;
a field effect transistor having its gate terminal coupled to its drain terminal and a signal ground node; and
a third resistor connected between a source terminal of the field effect transistor and the node at which the reference voltage is developed.
10. A circuit according to claim 9, wherein the third resistor comprises a plurality of resistors connected in series between the source terminal of the field effect transistor and the node at which the variable voltage is developed, and wherein the voltage generator circuit further comprises a plurality of switches, respective ones of which are coupled in parallel with respective ones of the plurality of resistors.
11. A circuit according to claim 1, wherein the DA comparison circuit comprises:
a voltage generator circuit that generates a reference voltage and a variable voltage responsive to the sense current;
a scaling circuit that scales the reference voltage responsive to the digital value; and
a voltage comparator that generates the comparison signal responsive to a comparison of the variable voltage and the scaled reference voltage.
12. A circuit according to claim 11, wherein the scaling circuit comprises:
a plurality of resistors coupled in series between a node that develops the reference voltage and a signal ground node; and
a plurality of switches, respective ones of which are configured to bypass respective ones of the plurality of resistors responsive to respective bits of the digital value at the digital input.
13. A circuit according to claim 11, wherein the voltage generator circuit comprises a bandgap reference circuit.
14. A circuit according to claim 11, wherein the DA comparison circuit has a reference adjustment input, and wherein the voltage generator circuit is operative to adjust the reference voltage responsive to a digital value at the reference adjustment input.
15. A circuit according to claim 14, wherein the voltage generator circuit comprises:
a plurality of resistors coupled in series between a node that develops the reference voltage and a signal ground node; and
a plurality of switches, respective ones of which are configured to bypass respective ones of the plurality of resistors responsive to respective bits of the digital value at the reference adjustment input.
16. A circuit according to claim 11, wherein the voltage generator circuit comprises:
a first resistor connected between the sense current input and a node at which the reference voltage is developed;
a second resistor connected between the node at which the reference voltage is developed and a node at which the variable voltage is developed; and
a bipolar transistor having its base terminal coupled to its collector terminal and a signal ground node and its emitter terminal coupled to the node at which the variable voltage is developed.
17. A circuit according to claim 16, wherein the second resistor comprises a plurality of resistors connected in series between the emitter terminal of the bipolar transistor and the node at which the reference voltage is developed, and wherein the voltage generator circuit further comprises a plurality of switches, respective ones of which are coupled in parallel with respective ones of the plurality of resistors.
18. A circuit according to claim 11, wherein the voltage generator circuit comprises:
a first resistor connected between the sense current input and a node at which the reference voltage is developed;
a second resistor connected between the node at which the reference voltage is developed and a node at which the variable voltage is developed; and
a field effect transistor having its gate terminal coupled to its drain terminal and a signal ground node and its source terminal coupled to the node at which the variable voltage is developed.
19. A circuit according to claim 18, wherein the second resistor comprises a plurality of resistors connected in series between the source terminal of the field effect transistor and the node at which the reference voltage is developed, and wherein the voltage generator circuit further comprises a plurality of switches, respective ones of which are coupled in parallel with respective ones of the plurality of resistor.
20. A circuit according to claim 1, further comprising an adjustment circuit operative to control the first voltage andor the second voltage.
21. A temperature sensor comprising:
a digital to analog (DA) comparison circuit comprising an analog sense current input, a digital input and a plurality of series-coupled resistors through which an analog sense current at the analog sense current input passes, the DA comparison circuit configured to generate first and second voltages responsive to respective nodes of the plurality of series-coupled resistors, to scale the second voltage responsive to a digital value at the digital input and to compare the scaled second voltage to the first voltage to generate a comparison signal;
a control circuit configured to provide digital values to the digital input of the DA comparison circuit responsive to the comparison signal and to generate a digital output corresponding to the sense current; and
a temperature transducer operative to generate a current at the analog current sense input responsive to temperature.
22. A sensor according to claim 21, wherein the DA comparison circuit comprises:
a voltage generator circuit that generates a reference voltage and a variable voltage responsive to the sense current;
a scaling circuit that scales a first one of the variable voltage and the reference voltage responsive to the digital value; and
a voltage comparator that generates the comparison signal responsive to a comparison of the scaled first one of the variable voltage and the reference voltage to a second one of the variable voltage and the reference voltage.
23. A sensor according to claim 22, further comprising an adjustment circuit operative to adjust the reference voltage.
24. A sensor according to claim 21, wherein the DA comparison circuit and the control circuit are included in an integrated circuit.
25. A liquid crystal display (LCD) driving integrated circuit (IC) comprising:
a digital to analog (DA) comparison circuit comprising an analog sense current input, a digital input and a plurality of series-coupled resistors through which an analog sense current at the analog sense current input passes, the DA comparison circuit configured to generate first and second voltages responsive to respective nodes of the plurality of series-coupled resistors, to scale the second voltage responsive to a digital value at the digital input and to compare the scaled second voltage to the first voltage to generate a comparison signal;
a control circuit configured to provide digital values to the digital input of the DA comparison circuit responsive to the comparison signal and to generate a digital output corresponding to the sense current; and
an LCD driving circuit operative to drive an LCD responsive to the generated digital output.
26. An LCD driving IC according to claim 25, wherein the DA comparison circuit comprises:
a voltage generator circuit that generates a reference voltage and a variable voltage responsive to the sense current;
a scaling circuit that scales a first one of the variable voltage and the reference voltage responsive to the digital value; and
a voltage comparator that generates the comparison signal responsive to a comparison of the scaled first one of the variable voltage and the reference voltage to a second one of the variable voltage and the reference voltage.
27. An LCD driving IC according to claim 25, further comprising an adjustment circuit operative to adjust the first voltage andor the second voltage.
28. An LCD driving IC according to claim 25, wherein the sense current represents temperature.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A device for the implantation of occluding spirals able to be severed by electrolysis in body cavities or blood vessels comprising a source of electrical power, a cathode, a catheter and an occluding spiral adapted to serve as an anode and able to slide in the catheter in the longitudinal direction, the occluding spiral is designed to be electrolytically corrodible at a plurality of spaced apart points so that when in contact with a body fluid one or more variably dimensioned lengths of the occluding spiral may be severed by electrolysis, characterized in that the occluding coil is designed to be continuously electrically conductive in the proximal-distal direction.
2. The device as set forth in claim 1, characterized in that an insertion means, in the form of a guide wire, proximally adjoins the occluding spiral.
3. The device as set forth in claim 2, characterized in that the guide wire and the occluding spiral are joined together by soldering, brazing andor bonding andor welding operations andor by mechanical connections.
4. The device as set forth in claim 2, characterized in that the guide wire and the occluding spiral are manufactured in the form of parts of the same wire.
5. The device as set forth in claim 1 or 2, characterized in that the occluding spiral or a part thereof is in the form of a micro-spiral.
6. The device as set forth in claim 1 or 2, characterized in that the occluding spiral or a part thereof is subject to a biasing stress and after release from the catheter forms coils.
7. The device as set forth in claim 1 or 2, characterized in that the electrolytically non-corrodible sections of the occluding spiral comprise one or more of the following materials: noble metals or noble metal alloys, corrosion-resistant ceramic materials, and corrosion-resistant plastics.
8. The device as set forth in claim 1 or 2, characterized in that the electrolytically corrodible points of the occluding spiral comprise one or more of the following materials: corrosion-resistant ceramic materials, corrosion-resistant plastics, and base metals or alloys thereof.
9. The device as set forth in claim 1 or 2, characterized in that AISI 301, 304 or 316 stainless steel are employed for the formation of the electrolytically corrodible points.
10. The device as set forth in claim 1 or 2, characterized in that for forming the electrolytically non-corrodible sections adjacent to transitions to the electrolytically corrodible points combinations of materials are selected which are suitable for forming local elements.
11. The device as set forth in claim 10, characterized in that the combinations of materials selected from groups consisting of the following are utilized:
a) stainless steels for the formation of the electrolytically corrodible points with noble metals for the formation of the electrolytically non-corrodible sections;
b) Ti or TiNi alloys for the formation of the electrolytically corrodible points with noble metals or noble metal alloys for the formation of the electrolytically non-corrodible sections;
c) Co based alloys for the formation of the electrolytically corrodible point with noble metal or noble metal alloys for the formation of the electrolytically non-corrodible sections.
12. The device as set forth in claim 5, characterized in that the points on the coils of the micro-spiral coil are shaped to be electrolytically corrodible points.
13. The device as set forth in claim 1 or 2, characterized in that the electrolytically corrodible points are on the micro-coils of the micro-spiral.
14. The device as set forth in claim 1 or 2, characterized in that the electrolytically corrodible points are aligned with the longitudinal axis of the occluding spiral.
15. The device as set forth in claim 1 or 2, characterized in that the electrolytically corrodible points are constituted by fittings which are fitted between the electrolytically non-corrodible sections of the occluding spiral.
16. The device as set forth in claim 1 or 2, characterized in that the fittings constituting the electrolytically corrodible points are joined to the electrolytically noncorrodible sections by soldering andor brazing andor bonding andor welding operations andor by mechanical methods.
17. The device as set forth in claim 1 or 2, characterized in that the electrolytically corrodible points are pre-corroded.
18. The device as set forth in claim 1 or 2, characterized in that the fittings constituting the electrolytically corrodible points are pre-corroded.
19. The device as set forth in claim 1 or 2, characterized in that the fittings are partly coated with a material, which is higher up in the electrochemical series than the material forming the fittings.
20. The device as set forth in claim 19, characterized in that the fittings consist of stainless steel and the coating consists of Zn, Zn alloys, Sn or Sn alloys.
21. The device as set forth in claim 15, characterized in that the fittings constituting the electrolytically corrodible points are micro-system components.
22. The device as set forth in claim 21, characterized in that the micro-system components contain micro-severance points as electrolytically corrodible points.
23. The device as set forth in claim 1 or 2, characterized in that the occluding spiral or a part thereof contains a continuous wire core of electrolytically corrodible material, which is surrounded by a casing repeatedly interrupted at intervals along the longitudinal axis and made of electrolytically corrosion resistant material.
24. The device as set forth in claim 1 or 2, characterized in that the diameter of the electrolytically corrodible points is between 0.01 and 0.05 mm.
25. The device as set forth in claim 1 or 2, characterized in that the end of the guide wire is provided with a coating preventing corrosion of the guide wire.
26. The device as set forth in claim 1 or 2 for methods used in veterinary or human medicine and preferably far thrombozation.
27. The device as set forth in claim 7 wherein the electrolytically non-corrodible sections of the occluding coil comprise platinum metal alloys.
28. The device as set forth in claim 8 wherein the electrolytically corrodible points of the occluding coil comprise stainless steel.
29. The device as set forth in claim 11 wherein the stainless steels are AISI 301, 304, 316 stainless steels.
30. The device as set forth in claim 11 wherein the noble metal combined with stainless steel is Pt or Pt metals, Pt alloys, Au alloys or Sn alloys.
31. The device as set forth in claim 11 wherein the noble metals or noble metal alloys combined with Ti or TiNi alloys are Pt, pt metals, Pt alloys, Au alloys or Sn alloys.
32. The device as set forth in claim 11 wherein the noble metals or noble metal alloys combined with Co based alloys are Pt, pt metals, Pt alloys, Au alloys or Sn alloys.
33. The device as set forth in claim 24 wherein the the diameter of the electrolytically corrodible points is between 0.02 and 0.04 mm.
34. The device as set forth in claim 24 wherein the the diameter of the electrolytically corrodible points is 0.03 mm.