Adaptive dead time control
First Claim
1. A system comprising:
- a dead time detector that detects when a dead time occurs and that generates an output signal based on a duration of the dead time, wherein the dead time is a period of time during which a high-side switch and a low-side switch of a switching regulator are turned off;
a first circuit that generates a first turn-on signal to turn on the high-side switch and a first turn-off signal to turn off the low-side switch based on the output signal in response to a first edge of a pulse width modulated pulse;
a second circuit that generates a second turn-on signal to turn on the low-side switch and a second turn-off signal to turn off the high-side switch based on the output signal in response to a second edge of the pulse width modulated pulse; and
a controller that generates a first gate drive signal to drive the high-side switch and a second gate drive signal to drive the low-side switch based on the first and second turn-on and turn-off signals,wherein the controller comprises a propagation delay control circuit that controls a propagation delay of the switching regulator by turning off the high-side and low-side switches when the pulse width modulated pulse changes state,wherein the propagation delay is defined as a delay between a time when a pulse width modulator issues a pulse width modulated pulse and a time when a switching node between the high-side and low-side switches is in fact switched according to the pulse width modulated pulse; and
wherein the controller regulates the dead time to a predefined target value while maintaining the propagation delay within a predetermined limit.
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Accused Products
Abstract
A dead time detector detects when a dead time occurs in a switching regulator comprising a high-side switch and a low-side switch and generates an output signal based on a duration of the dead time. A first circuit generates a first turn-on signal to turn on the high-side switch and a first turn-off signal to turn off the low-side switch based on the output signal in response to a first edge of a pulse width modulated pulse. A second circuit generates a second turn-on signal to turn on the low-side switch and a second turn-off signal to turn off the high-side switch based on the output signal in response to a second edge of the pulse width modulated pulse. A controller generates drive signals to drive the high-side and low-side switches based on the first and second turn-on and turn-off signals.
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Citations
25 Claims
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1. A system comprising:
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a dead time detector that detects when a dead time occurs and that generates an output signal based on a duration of the dead time, wherein the dead time is a period of time during which a high-side switch and a low-side switch of a switching regulator are turned off; a first circuit that generates a first turn-on signal to turn on the high-side switch and a first turn-off signal to turn off the low-side switch based on the output signal in response to a first edge of a pulse width modulated pulse; a second circuit that generates a second turn-on signal to turn on the low-side switch and a second turn-off signal to turn off the high-side switch based on the output signal in response to a second edge of the pulse width modulated pulse; and a controller that generates a first gate drive signal to drive the high-side switch and a second gate drive signal to drive the low-side switch based on the first and second turn-on and turn-off signals, wherein the controller comprises a propagation delay control circuit that controls a propagation delay of the switching regulator by turning off the high-side and low-side switches when the pulse width modulated pulse changes state, wherein the propagation delay is defined as a delay between a time when a pulse width modulator issues a pulse width modulated pulse and a time when a switching node between the high-side and low-side switches is in fact switched according to the pulse width modulated pulse; and wherein the controller regulates the dead time to a predefined target value while maintaining the propagation delay within a predetermined limit. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A system comprising:
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a dead time detector that detects when a dead time occurs and that generates an output signal based on a duration of the dead time, wherein the dead time is a period of time during which a high-side switch and a low-side switch of a switching regulator are turned off; a first circuit that generates a first turn-on signal to turn on the high-side switch and a first turn-off signal to turn off the low-side switch based on the output signal in response to a first edge of a pulse width modulated pulse; a second circuit that generates a second turn-on signal to turn on the low-side switch and a second turn-off signal to turn off the high-side switch based on the output signal in response to a second edge of the pulse width modulated pulse; and a controller that generates a first gate drive signal to drive the high-side switch and a second gate drive signal to drive the low-side switch based on the first and second turn-on and turn-off signals, wherein the dead time detector comprises; a voltage amplifier that generates a differential voltage based on a threshold voltage and a voltage at a node where the high-side and low-side switches are connected in series; and a transconductance amplifier that outputs a positive current as the output signal based on the differential voltage when the dead time occurs. - View Dependent Claims (14, 15)
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16. A system of comprising:
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a dead time detector that detects when a dead time occurs and that generates an output signal based on a duration of the dead time, wherein the dead time is a period of time during which a high-side switch and a low-side switch of a switching regulator are turned off; a first circuit that generates a first turn-on signal to turn on the high-side switch and a first turn-off signal to turn off the low-side switch based on the output signal in response to a first edge of a pulse width modulated pulse; a second circuit that generates a second turn-on signal to turn on the low-side switch and a second turn-off signal to turn off the high-side switch based on the output signal in response to a second edge of the pulse width modulated pulse; and a controller that generates a first gate drive signal to drive the high-side switch and a second gate drive signal to drive the low-side switch based on the first and second turn-on and turn-off signals, wherein the first circuit comprises; a timer that generates a pulse having a predetermined pulse width in response to the first edge of the pulse width modulated pulse; an integrator that performs a weighted time-integral of the output signal of the dead time detector over a time period equal to the predetermined pulse width and that generates an output voltage; and a differential voltage-to-time converter that compares a reference voltage to the output voltage of the integrator and that generates the first turn-on and turn-off signals based on the comparison.
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17. A system comprises:
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a dead time detector that detects when a dead time occurs and that generates an output signal based on a duration of the dead time, wherein the dead time is a period of time during which a high-side switch and a low-side switch of a switching regulator are turned off; a first circuit that generates a first turn-on signal to turn on the high-side switch and a first turn-off signal to turn off the low-side switch based on the output signal in response to a first edge of a pulse width modulated pulse; a second circuit that generates a second turn-on signal to turn on the low-side switch and a second turn-off signal to turn off the high-side switch based on the output signal in response to a second edge of the pulse width modulated pulse; and a controller that generates a first gate drive signal to drive the high-side switch and a second gate drive signal to drive the low-side switch based on the first and second turn-on and turn-off signals, wherein the second circuit comprises; a timer that generates a pulse having a predetermined pulse width in response to the second edge of the pulse width modulated pulse; an integrator that performs a weighted time-integral of the output signal of the dead time detector over a time period equal to the predetermined pulse width and that generates an output voltage; and a differential voltage-to-time converter that compares a reference voltage to the output voltage of the integrator and that generates the second turn-on and turn-off signals based on the comparison.
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18. A method comprising:
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detecting when a dead time occurs, wherein the dead time is a period of time during which a high-side switch and a low-side switch of a switching regulator are turned off; generating an output signal based on a duration of the dead time; generating a first turn-on signal to turn on the high-side switch and a first turn-off signal to turn off the low-side switch based on the output signal in response to a first edge of a pulse width modulated pulse; generating a second turn-on signal to turn on the low-side switch and a second turn-off signal to turn off the high-side switch based on the output signal in response to a second edge of the pulse width modulated pulse; generating a first gate drive signal to drive the high-side switch and a second gate drive signal to drive the low-side switch based on the first and second turn-on and turn-off signals; controlling a propagation delay of the switching regulator by turning off the high-side and low-side switches when the pulse width modulated pulse changes state, wherein the propagation delay is defined as a delay between a time when a pulse width modulator issues a pulse width modulated pulse and a time when a switching node between the high-side and low-side switches is in fact switched according to the pulse width modulated pulse; and regulating the dead time to a predefined target value while maintaining the propagation delay within a predetermined limit. - View Dependent Claims (19, 20, 21, 22, 23, 24, 25)
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Specification