System and method for robust body braking control to suppress transient voltage overshoot

1. A voltage regulator, comprising:

a first power stage for a first phase of the voltage regulator, the first power stage including a first temperature sensor for the first phase, the first temperature sensor switched onto a shared bus to a controller, the first power stage configured to:

provide first power to a load in response to a first pulse-width modulated (PWM) signal;

switch first temperature information from the first temperature sensor onto the shared bus in response to a rising edge of the first PWM signal; and

provide a first body braking for the load in response to a first body braking signal, wherein the first body braking is provided via a first body diode of the first power stage;

a second power stage for a second phase of the voltage regulator, the second power stage including a second temperature sensor for the second phase, the second temperature sensor switched onto the shared bus to the controller, the second power stage configured to:

provide second power to the load in response to a second PWM signal;

switch second temperature information from the second temperature sensor onto the shared bus in response to a rising edge of the second PWM signal; and

provide a second body braking for the load in response to a second body braking signal, wherein the second body braking is provided via a second body diode of the second power stage; and

the controller configured to:

provide the first PWM signal to the first power stage and the second PWM signal to the second power stage based upon a power demand of the load;

provide the first body braking signal to the first power stage and the second body braking signal to the second power stage in response to an over-voltage condition on the load;

determine that an over-temperature indication is received while the first PWM signal is provided to the first power stage;

determine that the over-temperature indication is received from the first temperature sensor based upon determining that the over-temperature indication is received while the first PWM signal is provided; and

suspend the first body braking signal to the first power stage and maintain the second body braking signal to the second power stage, in response to determining that the over-temperature indication was received from the first temperature sensor.

2. The voltage regulator of claim 1 , wherein the controller is configured to:

receive the first temperature information from the shared bus, the first temperature information indicating the over-temperature condition; and

determine that the first temperature information is from the first sensor.

3. The voltage regulator of claim 2 , wherein:

the first temperature information is received at a time when the first PWM signal is in a high state; and

the controller determines that the first temperature information is from the first sensor based upon the first temperature information being receive at the time.

4. The voltage regulator of claim 2 , wherein:

the controller is further configured to provide a handshake signal to the first power stage;

the first temperature information is received in response to the controller providing the handshake signal; and

the controller determines that the first temperature information is from the first sensor based upon the first temperature information being receive subsequent to the handshake signal.

5. The voltage regulator of claim 2 , wherein the controller is further configured to:

receive the second temperature information from the shared bus, the second temperature information indicating the over-temperature condition has ended;

determine that the second temperature information is from the second sensor; and

provide the first body braking signal to the first power in response to determining that the second temperature information is from the second sensor.

6. The voltage regulator of claim 1 , wherein the first power stage includes a high-side power element and a low-side power element, the first body diode being integrated with the low-side power element.

7. The voltage regulator of claim 6 , wherein:

in response to a high state of the first PWM signal, the high-side power element is turned on to provide power to the load and the low-side power element is turned off;

in response to a low state of the first PWM signal, the high-side power element is turned off to isolate the load from a power source and the low-side power element is turned on; and

in response to the first body braking signal, the high-side power element and the low-side power element are turned off and the first body diode provides the first body braking.

8. The voltage regulator of claim 7 , wherein the first power stage further comprises a driver configured to receive the first PWM signal and the first body braking signal from the controller.

9. A method, comprising:

providing, by a first power stage of a voltage regulator, first power to a load in response to a first pulse-width modulated (PWM) signal, the first power stage for a first phase of the voltage regulator;

switching, by a first temperature sensor of the first power stage, first temperature information from the first temperature sensor onto a shared bus in response to a rising edge of the first PWM signal;

providing a first body braking to the load in response to a first body braking signal, wherein the first body braking is provided via a first body diode of the first power stage;

providing, by a second power stage of the voltage regulator, second power to the load in response to a second PWM signal, the second power stage for a second phase of the voltage regulator;

switching, by a second temperature sensor of the second power stage, second temperature information from the second temperature sensor onto the shared bus in response to a rising edge of the second PWM signal;

providing a second body braking to the load in response to a second body braking signal, wherein the second body braking is provided via a second body diode of the second power stage;

providing, by a controller of the voltage regulator, the first PWM signal to the first power stage and the second PWM signal to the second power stage based upon a power demand of the load;

providing, by the controller, the first body braking signal to the first power stage and the second body braking signal to the second power stage in response to an over-voltage condition on the load;

receiving, via a shared bus, third temperature information;

determining that the third temperature information is received while the first PWM signal is provided to the first power stage;

determining that the third temperature information is the first temperature information based upon determining that the third temperature information is received while the first PWM signal is provided;

receiving, via the shared bus, the fourth temperature information; and

determining that the fourth temperature information is received while the second PWM signal is provided to the second power stage;

determining that the fourth temperature information is the second temperature information based upon determining that the fourth temperature information is received while the second PWM signal is provided; and

suspending, by the controller, the first body braking signal to the first power stage and not suspending the second body braking signal to the second power stage, in response to an over-temperature indication from the first temperature sensor.

10. The method of claim 9 , further comprising:

receiving, by the controller, the first temperature information from the shared bus, the first temperature information indicating the over-temperature condition; and

determining, by the controller, that the first temperature information is from the first sensor.

11. The method of claim 10 , wherein:

the first temperature information is received at a time when the first PWM signal is in a high state; and

determining that the first temperature information is from the first sensor is based upon the first temperature information being receive at the time.

12. The method of claim 10 , further comprising:

providing, by the controller, a handshake signal to the first power stage, wherein:

the first temperature information is received in response to the controller providing the handshake signal; and

determining that the first temperature information is from the first sensor is based upon the first temperature information being receive subsequent to the handshake signal.

13. The method of claim 10 , further comprising:

receiving, by the controller, the second temperature information from the shared bus, the second temperature information indicating the over-temperature condition has ended;

determining, by the controller, that the second temperature information is from the second sensor; and

providing, by the controller, the first body braking signal to the first power in response to determining that the second temperature information is from the second sensor.

14. The method of claim 9 , wherein the first power stage includes a high-side power element and a low-side power element, the first body diode being integrated with the low-side power element.

15. The method of claim 14 , wherein:

turning on the high-side power element to provide power to the load and turning off the low-side power element in response to a high state of the first PWM signal;

turning off the high-side power element to isolate the load from a power source and turning on the low-side power element in response to a low state of the first PWM signal; and

turning off the high-side power element and the low-side power element and permitting the first body diode to provide the first body braking in response to the first body braking signal.

16. A voltage regulator, comprising:

a first power stage including a first control input, a second control input, a first power output, and a first temperature sensor output, the first power stage configured to:

provide power to the first load output in a first phase of the voltage regulator in response to a first pulse-width modulated (PWM) signal receive on the first control input;

determine that a control signal is received on the second control input concurrently with the receipt of the first PWM signal on the first control input;

provide first temperature information on the first temperature sensor output on the shared bus in response to determining that the control signal was received on the second input concurrently with the first PWM signal; and

provide a first body braking to the first load output in response to a first body braking signal received on the first control input, the first body braking being provided via a first body diode of the first power stage;

a second power stage including a third control input, a fourth control input, a second power output, and a second temperature sensor output, the second power stage configured to:

provide power to the second load output in a second phase of the voltage regulator in response to a second PWM signal receive on the third control input;

determine that the control signal is received on the fourth control input concurrently with the receipt of the second PWM signal on the third control input;

provide second temperature information on the second temperature sensor output on the shared bus in response to determining that the control signal was received on the fourth control input concurrently with the second PWM signal; and

provide a second body braking to the second load output in response to a second body braking signal received on the third control input, the second body braking being provided via a second body diode of the second power stage; and

a controller including a first control output coupled to the first control input, a second control output coupled to the third control input, a third control output coupled to the second and fourth control inputs, and a temperature sensor input coupled via a shared bus to the first temperature sensor output and the second temperature sensor output, the controller configured to:

provide the first PWM signal on the first control output and the second PWM signal on the second control output based upon a power demand of a load;

provide the first body braking signal on the first control output and the second body braking signal on the second control output in response to an over voltage condition on the load;

provide the control signal on the third control output concurrently with the provision of the first PWM signal on the first control output;

receive the first temperature information from the first temperature sensor output on the first temperature sensor input in response to an over temperature condition on the first power stage; and

suspend the first body braking signal to the first power stage and maintain the second body braking signal to the second power stage, in response to an over-temperature condition detected by the first temperature sensor.

17. The voltage regulator of claim 16 , wherein the controller is configured to:

determine that the first temperature information is from the first sensor.

18. The voltage regulator of claim 16 , wherein:

the first temperature information is received at a time when the first PWM signal is in a high state; and

the controller determines that the first temperature information is from the first sensor based upon the first temperature information being receive at the time.