Surgical generator for ultrasonic and electrosurgical devices

1. A control circuit configured to receive a control signal from a surgical generator, the control signal defining a first phase and a second phase, the control circuit comprising:

a first resistor;

a second resistor in parallel with the first resistor; and

a switch in series with the second resistor, the switch configured to transition between an open state and a closed state corresponding to an operational mode of a surgical instrument;

wherein, in the first phase of the control signal, the control circuit is configured to communicate surgical instrument information to the surgical generator;

wherein, in the second phase of the control signal and in the open state of the switch, the control circuit is configured to provide a first output;

wherein, in the second phase of the control signal and in the closed state of the switch, the control circuit is configured to provide a second output.

2. The control circuit of claim 1 , further comprising:

a capacitor coupled in series with the first resistor and the second resistor;

wherein a state of the switch is determinable based on a slope of a voltage of the capacitor.

3. The control circuit of claim 1 , wherein the switch is coupled to a pushbutton disposed on the surgical instrument.

4. The control circuit of claim 1 , further comprising:

a memory device storing the surgical instrument information;

wherein the memory device is powered in the first phase of the control signal to communicate the surgical instrument information to and from the surgical generator.

5. The control circuit of claim 4 , wherein the memory device comprises an electrically erasable programmable read-only memory.

6. The control circuit of claim 1 , wherein:

the control signal comprises a differential constant current pulse;

the first phase comprises a positive phase of the differential constant current pulse; and

the second phase comprises a negative phase of the differential constant current pulse.

7. The control circuit of claim 1 , wherein the surgical instrument information is selected from the group consisting of a number of uses of the surgical instrument, a date of use of the surgical instrument, a time of use of the surgical instrument, a model number, a serial number, and any combination thereof.

8. A control circuit configured to receive a control signal from a surgical generator, the control signal defining a first phase and a second phase, the control circuit comprising:

a resistor network comprising resistors arranged in parallel to each other;

a switch electrically coupled in series to the resistor network, wherein the switch is configured to transition between a plurality of states corresponding to a plurality of operational modes of a surgical instrument;

wherein, in the first phase of the control signal, the control circuit is configured to communicate surgical instrument information to the surgical generator;

wherein, in the second phase of the control signal and when the switch is in a first state of the plurality of states, the control circuit is configured to provide a first output; and

wherein, in the second phase of the control signal and when the switch is in a second state of the plurality of states, the control circuit is configured to provide a second output.

9. The control circuit of claim 8 , further comprising:

a plurality of switches, each of the switches configured to transition between an open state and a closed state;

wherein the plurality of switches are configured to transition the control circuit between a plurality of outputs.

10. The control circuit of claim 9 , further comprising:

a capacitor coupled in series with the resistor network;

wherein a state of the plurality of switches is determinable based on a slope of a voltage of the capacitor.

11. The control circuit of claim 9 , wherein each of the switches of the plurality of switches is coupled to a pushbutton disposed on the surgical instrument.

12. The control circuit of claim 8 , further comprising:

a memory device storing the surgical instrument information;

wherein the memory device is powered in the first phase of the control signal to communicate the surgical instrument information to and from the surgical generator.

13. The control circuit of claim 12 , wherein the memory device comprises an electrically erasable programmable read-only memory.

14. The control circuit of claim 8 , wherein:

the control signal comprises a differential constant current pulse;

the first phase defines a positive phase of the differential constant current pulse; and

the second phase defines a negative phase of the differential constant current pulse.

15. The control circuit of claim 8 , wherein the surgical instrument information is selected from the group consisting of a number of uses of the surgical instrument, a date of use of the surgical instrument, a time of use of the surgical instrument, a model number, a serial number, and any combination thereof.

16. A control circuit configured to receive a control signal from a surgical generator, the control signal defining a first phase and a second phase, the control circuit comprising:

a resistor network comprising n+1 resistors arranged in parallel to each other; and

a switch network comprising n switches, each of the switches configured to transition between an open state and a closed state corresponding to a plurality of operational modes of a surgical instrument;

wherein each of the switches is arranged in series with one of the resistors;

wherein, in the first phase of the control signal, the control circuit is configured to communicate surgical instrument information to the surgical generator;

wherein, in the second phase of the control signal, the control circuit is configured to provide a plurality of different outputs based on various combinations of the switches being in the open state or the closed state.

17. The control circuit of claim 16 , further comprising:

a capacitor coupled in series with the resistor network;

wherein a state of the switch network is determinable based on a slope of a voltage of the capacitor.

18. The control circuit of claim 16 , wherein each of the switches is coupled to a pushbutton disposed on the surgical instrument.

19. The control circuit of claim 16 , further comprising:

a memory device storing the surgical instrument information;

wherein the memory device is powered in the first phase of the control signal to communicate the surgical instrument information to and from the surgical generator.

20. The control circuit of claim 19 , wherein the memory device comprises an electrically erasable programmable read-only memory.

21. The control circuit of claim 16 , wherein:

the control signal comprises a differential constant current pulse;

the first phase defines a positive phase of the differential constant current pulse; and

the second phase defines a negative phase of the differential constant current pulse.

22. The control circuit of claim 16 , wherein the surgical instrument information is selected from the group consisting of a number of uses of the surgical instrument, a date of use of the surgical instrument, a time of use of the surgical instrument, a model number, a serial number, and any combination thereof.

23. The control circuit of claim 8 , wherein the switch is open in the first state, and wherein the switch is closed in the second state.