Adaptive clamping circuitry

1. A power supply system, comprising:

a primary side circuitry and a secondary side circuitry to generate an output voltage from an input voltage, at least the secondary side circuitry comprising a plurality of switches; and

adaptive clamping circuitry to generate at least one of an adjustable clamping current or voltage based on a result of a comparison of the input voltage to a plurality of threshold voltages to prevent a switch voltage for the plurality of switches from exceeding a drain-source (Vds) breakdown voltage.

2. The power supply system of claim 1 , wherein the adaptive clamping circuitry is coupled to the secondary side between the plurality of switches and the output voltage.

3. The power supply system of claim 1 , wherein the adaptive clamping circuitry comprises at least clamping current generation circuitry and controller circuitry to generate control signals to control operation of the clamping current generation circuitry.

4. The power supply system of claim 3 , wherein the clamping current generation circuitry comprises a plurality of resistors arranged in parallel and switches coupled to each of the plurality of resistors to controllably couple each of the resistors to, or decouple each of the resistors from, the power supply system in response to the control signals.

5. The power supply system of claim 3 , wherein the clamping current generation circuitry comprises a plurality of current sources arranged in parallel and switches coupled to each of the plurality of current sources to controllably couple each of the current sources to, or decouple each of the current sources from, the power supply system in response to the control signals.

6. The power supply system of claim 3 , wherein the controller circuitry comprises a plurality of operational amplifiers and state machine circuitry.

7. The power supply system of claim 6 , wherein each of the plurality of operational amplifiers is to compare the input voltage to a threshold voltage, generate a first voltage level if the input voltage is higher than the threshold voltage and generate a second voltage level if the input voltage is less than the threshold voltage.

8. The power supply system of claim 7 , wherein the state machine circuitry comprises logic to generate the control signals based on the voltage levels, wherein the logic is to generate the control signals to prevent the switch voltage for the plurality of switches from exceeding the Vds breakdown voltage.

9. Adaptive clamping circuitry, comprising:

clamping current generation circuitry to generate a clamping current to prevent a switch voltage for at least one switch from exceeding a drain-source (Vds) breakdown voltage; and

controller circuitry to generate control signals to control the operation of the clamping current generation circuitry based on a comparison of an input voltage to a plurality of threshold voltages.

10. The adaptive clamping circuitry of claim 9 , wherein the clamping current generation circuitry comprises a plurality of resistors arranged in parallel and switches coupled to each of the plurality of resistors to controllably couple each of the resistors to, or decouple each of the resistors from, the power supply system in response to the control signals.

11. The adaptive clamping circuitry of claim 9 , wherein the clamping current generation circuitry comprises a plurality of current sources arranged in parallel and switches coupled to each of the plurality of current sources to controllably couple each of the current sources to, or decouple each of the current sources from, the power supply system in response to the control signals.

12. The adaptive clamping circuitry of claim 9 , wherein the controller circuitry comprises:

a plurality of operational amplifiers that each compare the input voltage to a threshold voltage, generate a first voltage level if the input voltage is higher than the threshold voltage and generate a second voltage level if the input voltage is less than the threshold voltage; and

state machine circuitry including logic to generate the control signals based on the voltage levels, wherein the logic is to generate the control signals to prevent the switch voltage for the at least one switch from exceeding the Vds breakdown voltage.

13. A method for controlling adaptive clamping circuitry comprising:

determining a condition of a power supply system including at least a plurality of switches on a secondary side of the power supply system to determine if a switch voltage for the plurality of switches could potentially exceed a drain-source (Vds) breakdown voltage; and

controlling adaptive clamping circuitry in the power supply system to generate at least one of an adjustable clamping current or voltage based on the determination,

wherein determining a condition of the power supply system comprises comparing an input voltage for the power supply system to a plurality of threshold voltages in the adaptive clamping circuitry.

14. The method of claim 13 , wherein controlling the adaptive clamping circuitry comprises causing switches in the adaptive clamping circuitry to controllably couple each of a plurality of resistors or current sources arranged in parallel to the power supply system based on control signals generated by state machine circuitry in the adaptive clamping circuitry.

15. The method of claim 13 , wherein controlling the adaptive clamping circuitry comprises controlling a controllable current source in the adaptive clamping circuitry based on a control signal generated by amplifier circuitry in the adaptive clamping circuitry.

16. An adaptive clamping circuit for a power supply, the adaptive clamping circuit comprising:

a clamp capacitor;

a clamping current generation circuit that is configured to generate a clamping current from the clamp capacitor to prevent a switch voltage for at least one switch from exceeding a drain-source (Vds) breakdown voltage; and

a controller circuit that is configured to generate a control signal to adjust the clamping current based on a comparison of an input voltage of the power supply to a threshold voltage;

wherein the controller circuit comprises a plurality of comparator circuits that each compares the input voltage with one of a plurality of threshold voltages to generate a comparison output that controls the clamping current.

17. The adaptive clamping circuit of claim 16 , further comprising:

a plurality of controllable current sources that are controlled according to comparison outputs of the plurality of comparator circuits.

18. The adaptive clamping circuit of claim 16 , further comprising:

a plurality of switchable resistors that are controlled according to comparison outputs of the plurality of comparator circuits.