A pulse width modulated (PWM) amplifier includes a synchronization logic circuit having a first input configured to receive a bridge control signal and having a second input configured to receive a clock signal. The synchronization logic circuit is configured to provide a slope switch signal and a reference switch signal. The PWM amplifier includes a ramp generator having a first input configured to receive a first voltage supply and having a second input configured to receive a second voltage supply and having a third input configured to receive the reference switch signal and having a fourth input configured to receive the slope switch signal. The ramp generator is configured to provide a ramp signal having a first slope responsive to the slope switch signal in a first state and having a second slope responsive to the slope switch signal in a second state and to provide the clock signal.

A pulse width modulated (PWM) amplifier includes a synchronization logic circuit having a first input configured to receive a bridge control signal and having a second input configured to receive a clock signal. The synchronization logic circuit is configured to provide a slope switch signal and a reference switch signal. The PWM amplifier includes a ramp generator having a first input configured to receive a first voltage supply and having a second input configured to receive a second voltage supply and having a third input configured to receive the reference switch signal and having a fourth input configured to receive the slope switch signal. The ramp generator is configured to provide a ramp signal having a first slope responsive to the slope switch signal in a first state and having a second slope responsive to the slope switch signal in a second state and to provide the clock signal.

An auto-tuned ramp generator and a method for generating a sawtooth signal are provided. In the method and apparatus, a sawtooth signal is compared to a first reference voltage and a second reference voltage. In response to determining that the sawtooth signal does not exceed the first reference voltage, the voltage level of the sawtooth signal is increased. In response to determining that the sawtooth signal exceeds the second reference voltage, the voltage level of the sawtooth signal is decreased. The voltage level the sawtooth signal is retained if the sawtooth signal remains between the first and second reference voltages.

An auto-tuned ramp generator and a method for generating a sawtooth signal are provided. In the method and apparatus, a sawtooth signal is compared to a first reference voltage and a second reference voltage. In response to determining that the sawtooth signal does not exceed the first reference voltage, the voltage level of the sawtooth signal is increased. In response to determining that the sawtooth signal exceeds the second reference voltage, the voltage level of the sawtooth signal is decreased. The voltage level the sawtooth signal is retained if the sawtooth signal remains between the first and second reference voltages.

A ramp signal generation device includes a sampling circuit suitable for sampling a ramp current and storing a voltage corresponding to the sampled ramp current; a current maintaining circuit suitable for maintaining the ramp current; a current transferring circuit suitable for transferring a current corresponding to the voltage stored on the sampling circuit; and a current-to-voltage converter suitable for converting and generating a ramp voltage corresponding to the current transferred from the current transferring circuit.

A ramp signal generation device includes a sampling circuit suitable for sampling a ramp current and storing a voltage corresponding to the sampled ramp current; a current maintaining circuit suitable for maintaining the ramp current; a current transferring circuit suitable for transferring a current corresponding to the voltage stored on the sampling circuit; and a current-to-voltage converter suitable for converting and generating a ramp voltage corresponding to the current transferred from the current transferring circuit.

An auto-tuned ramp generator and a method for generating a sawtooth signal are provided. In the method and apparatus, a sawtooth signal is compared to a first reference voltage and a second reference voltage. In response to determining that the sawtooth signal does not exceed the first reference voltage, the voltage level of the sawtooth signal is increased. In response to determining that the sawtooth signal exceeds the second reference voltage, the voltage level of the sawtooth signal is decreased. The voltage level the sawtooth signal is retained if the sawtooth signal remains between the first and second reference voltages.

An auto-tuned ramp generator and a method for generating a sawtooth signal are provided. In the method and apparatus, a sawtooth signal is compared to a first reference voltage and a second reference voltage. In response to determining that the sawtooth signal does not exceed the first reference voltage, the voltage level of the sawtooth signal is increased. In response to determining that the sawtooth signal exceeds the second reference voltage, the voltage level of the sawtooth signal is decreased. The voltage level the sawtooth signal is retained if the sawtooth signal remains between the first and second reference voltages.

Aspects of this disclosure relate to reducing settling time of a sawtooth ramp signal in a phase-locked loop. Information from a loop filter of the phase-locked loop can be stored and used within the loop filter so as to improve the settling time of the sawtooth ramp signal. In certain embodiments, the settling time of a periodic sawtooth ramp signal can be reduced to less than one microsecond. An output frequency at the end of the sawtooth chirp can be brought back to an initial value without significantly modifying phase error in disclosed embodiments.

Aspects of this disclosure relate to reducing settling time of a sawtooth ramp signal in a phase-locked loop. Information from a loop filter of the phase-locked loop can be stored and used within the loop filter so as to improve the settling time of the sawtooth ramp signal. In certain embodiments, the settling time of a periodic sawtooth ramp signal can be reduced to less than one microsecond. An output frequency at the end of the sawtooth chirp can be brought back to an initial value without significantly modifying phase error in disclosed embodiments.