Abstract: Systems and methods for overcurrent protection in a battery charger are provided. For example, a method for overcurrent protection may include controlling a switching regulator to direct electrical current between the switching regulator and a battery port; sensing a voltage drop that is related to the electrical current passing between the switching regulator and the battery port; applying a first ramp voltage to the sensed voltage drop generating a modified sensed voltage drop; comparing the modified sensed voltage drop against at least one reference voltage; and when the modified sensed voltage drop exceeds the at least one reference voltage, changing operation of the switching regulator to protect the battery charger from an overcurrent state.

Abstract: A voltage regulator including a converter and a modulator. The converter includes a switching circuit coupled to an inductor for converting an input voltage to an output voltage. The modulator controls the switching circuit in a buck mode of operation, a boost mode of operation, and an intermediate buck-boost mode of operation. During the buck-boost mode of operation, the modulator controls the switching circuit during each switching cycle to sequentially switch between three different switching states, including a first switching state that applies the input voltage across the inductor, a second switching state that applies a difference between the input and output voltages across the inductor, and a third switching state that applies the output voltage across the inductor. The modulator is controlled based on voltage applied across or current flowing through the inductor to regulate the output voltage to a target level.

Abstract: A controller for controlling operation of a switching regulator including a modulator, a discontinuous conduction mode (DCM) controller, an audible DCM (ADCM) controller, and a sub-sonic discontinuous conduction mode (SBDCM) controller. The modulator generally operates in a continuous conduction mode. The DCM controller modifies operation to DCM during low loads. The ADCM controller detects when the switching frequency is less than a super-sonic frequency threshold and modifies operation to maintain the switching frequency at a super-sonic frequency level. The SBDCM controller detects a sub-sonic operating condition during ADCM operation and responsively inhibits operation of the ADCM mode controller to allow a SBDCM mode within a sub-sonic switching frequency range. The SBDCM operating mode allows for efficient connected standby operation. The SBDCM controller allows operation to return to other modes when the switching frequency increases above the subsonic level.

Abstract: An electronic system, DC-DC voltage converter, method of operating a buck-boost DC-DC converter, and method for power mode transitioning in a DC-DC voltage converter are disclosed. For example, one method includes receiving a compensated error signal associated with an output voltage of the DC-DC voltage converter, determining a power mode of operation of the DC-DC voltage converter, and if the power mode of operation is a first mode, outputting a first control signal to regulate the output voltage of the DC-DC voltage converter. If the power mode of operation is a second mode, outputting a second control signal to regulate the output voltage of the DC-DC voltage converter, and if the power mode of operation is a third mode, outputting a third control signal to regulate the output voltage of the DC-DC voltage converter.

Abstract: A voltage error signal is provided to a PWM controller of a voltage regular and used to produce a PWM signal that drives a power stage of the regulator. When operating in an adapter current limit regulation mode, an adapter current sense voltage, indicative of an adapter current, is compared to an adapter current reference voltage to produce an adapter current error signal. A compensator receives the adapter current error signal and outputs a compensated adapter current error signal. The adapter current sense voltage, or a high pass filtered version thereof, is subtracted from the compensated adapter current error signal to produce the voltage error signal provided to the PWM controller. Alternatively, an input voltage, or a high pass filtered version thereof, is added to the compensated adapter current error signal to produce the voltage error signal.

Abstract: An electronic system, DC-DC voltage converter, method of operating a buck-boost DC-DC converter, and method for power mode transitioning in a DC-DC voltage converter are disclosed. For example, one method includes receiving a compensated error signal associated with an output voltage of the DC-DC voltage converter, determining a power mode of operation of the DC-DC voltage converter, and if the power mode of operation is a first mode, outputting a first control signal to regulate the output voltage of the DC-DC voltage converter. If the power mode of operation is a second mode, outputting a second control signal to regulate the output voltage of the DC-DC voltage converter, and if the power mode of operation is a third mode, outputting a third control signal to regulate the output voltage of the DC-DC voltage converter.

Abstract: A current mode control regulator including a control circuit and a current generator. The control circuit regulates an output voltage based on a reference voltage using current mode control. The current generator applies an adjust current to a feedback current signal, in which the adjust current is proportional to a difference between a voltage indicative of the output voltage and the reference voltage to emulate an AC load resistance at an output of the current mode regulator. A load resistor emulator emulates an AC load resistor to increase the phase margin of current mode control regulator when operating without a battery coupled to the output, such as when the battery is physically removed or otherwise electrically disconnected. Operation is not substantially changed when the battery is connected, so that the desired phase margin is achieve with or without the battery.

Abstract: A voltage error signal VERR is provided to a PWM controller of a voltage regular and used to produce a PWM signal that drives a power stage of the regulator. When operating in an adaptor current limit regulation mode, an adaptor current sense voltage VACS, indicative of an adapter current IA, is compared to an adapter current reference voltage VAC_REF to produce an adapter current error signal VAC_ERR. A compensator receives the adapter current error signal VAC_ERR and outputs a compensated adapter current error signal. The adaptor current sense voltage VACS, or a high pass filtered version thereof, is subtracted from the compensated adapter current error signal to produce the voltage error signal VERR provided to the PWM controller. Alternatively, an input voltage VIN, or a high pass filtered version thereof, is added to the compensated adapter current error signal to produce the voltage error signal VERR.

Abstract: The system and method creates a substantially constant output voltage ripple in a buck converter in discontinuous conduction mode by varying the on-time of a pulse width modulator (PWM) signal driving the buck converter when the buck converter is operating in discontinuous conduction mode. A first signal is generated that is a function of the switching frequency of the buck converter. This signal is low-pass filtered and compared with a second signal that is a function of the switching frequency of the buck converter when operating in continuous conduction mode and with constant PWM on-time. The output signal generated by the comparator is a signal that is equal to the ratio of the first signal and the second signal. The on-time of a voltage controlled oscillator is controlled by the output signal, the oscillator signal causing the on-time of the PWM signal to vary in a controlled fashion.

Abstract: A hysteretic current mode buck-boost voltage regulator including a buck-boost voltage converter, a switching controller, a window circuit, a ramp circuit, and a timing circuit. The timing circuit may be additional ramp circuits. The voltage converter is toggled between first and second switching states during a boost mode, is toggled between third and fourth switching states during a buck mode, and is sequentially cycled through each switching state during a buck-boost mode. The ramp circuit develops a ramp voltage that simulates current through the voltage converter, and switching is determined using the ramp voltage compared with window voltages provided by the window circuit. The window voltages establish frequency, and may be adjusted based on the input and output voltages. The timing circuit provides timing indications during the buck-boost mode to ensure that the second and fourth switching states have approximately the same duration to provide symmetry of the ramp signal.

Abstract: A voltage regulator including a converter and a modulator. The converter includes a switching circuit coupled to an inductor for converting an input voltage to an output voltage. The modulator controls the switching circuit in a buck mode of operation, a boost mode of operation, and an intermediate buck-boost mode of operation. During the buck-boost mode of operation, the modulator controls the switching circuit during each switching cycle to sequentially switch between three different switching states, including a first switching state that applies the input voltage across the inductor, a second switching state that applies a difference between the input and output voltages across the inductor, and a third switching state that applies the output voltage across the inductor. The modulator is controlled based on voltage applied across or current flowing through the inductor to regulate the output voltage to a target level.

Abstract: A controller for controlling operation of a switching regulator including a modulator, a discontinuous conduction mode (DCM) controller, an audible DCM (ADCM) controller, and a sub-sonic discontinuous conduction mode (SBDCM) controller. The modulator generally operates in a continuous conduction mode. The DCM controller modifies operation to DCM during low loads. The ADCM controller detects when the switching frequency is less than a super-sonic frequency threshold and modifies operation to maintain the switching frequency at a super-sonic frequency level. The SBDCM controller detects a sub-sonic operating condition during ADCM operation and responsively inhibits operation of the ADCM mode controller to allow a SBDCM mode within a sub-sonic switching frequency range. The SBDCM operating mode allows for efficient connected standby operation. The SBDCM controller allows operation to return to other modes when the switching frequency increases above the subsonic level.

Abstract: The system and method creates a substantially constant output voltage ripple in a buck converter in discontinuous conduction mode by varying the on-time of a pulse width modulator (PWM) signal driving the buck converter when the buck converter is operating in discontinuous conduction mode. A first signal is generated that is a function of the switching frequency of the buck converter. This signal is low-pass filtered and compared with a second signal that is a function of the switching frequency of the buck converter when operating in continuous conduction mode and with constant PWM on-time. The output signal generated by the comparator is a signal that is equal to the ratio of the first signal and the second signal. The on-time of a voltage controlled oscillator is controlled by the output signal, the oscillator signal causing the on-time of the PWM signal to vary in a controlled fashion.

Abstract: A hysteretic current mode buck-boost voltage regulator including a buck-boost voltage converter, a switching controller, a window circuit, a ramp circuit, and a timing circuit. The timing circuit may be additional ramp circuits. The voltage converter is toggled between first and second switching states during a boost mode, is toggled between third and fourth switching states during a buck mode, and is sequentially cycled through each switching state during a buck-boost mode. The ramp circuit develops a ramp voltage that simulates current through the voltage converter, and switching is determined using the ramp voltage compared with window voltages provided by the window circuit. The window voltages establish frequency, and may be adjusted based on the input and output voltages. The timing circuit provides timing indications during the buck-boost mode to ensure that the second and fourth switching states have approximately the same duration to provide symmetry of the ramp signal.

Abstract: An electronic system, DC-DC voltage converter, method of operating a buck-boost DC-DC converter, and method for power mode transitioning in a DC-DC voltage converter are disclosed. For example, one method includes receiving a compensated error signal associated with an output voltage of the DC-DC voltage converter, determining a power mode of operation of the DC-DC voltage converter, and if the power mode of operation is a first mode, outputting a first control signal to regulate the output voltage of the DC-DC voltage converter. If the power mode of operation is a second mode, outputting a second control signal to regulate the output voltage of the DC-DC voltage converter, and if the power mode of operation is a third mode, outputting a third control signal to regulate the output voltage of the DC-DC voltage converter.

Abstract: A controller for controlling operation of a switching regulator including a modulator, a discontinuous conduction mode (DCM) controller, an audible DCM (ADCM) controller, and a sub-sonic discontinuous conduction mode (SBDCM) controller. The modulator generally operates in a continuous conduction mode. The DCM controller modifies operation to DCM during low loads. The ADCM controller detects when the switching frequency is less than a super-sonic frequency threshold and modifies operation to maintain the switching frequency at a super-sonic frequency level. The SBDCM controller detects a sub-sonic operating condition during ADCM operation and responsively inhibits operation of the ADCM mode controller to allow a SBDCM mode within a sub-sonic switching frequency range. The SBDCM operating mode allows for efficient connected standby operation. The SBDCM controller allows operation to return to other modes when the switching frequency increases above the sub-sonic level.

Abstract: An apparatus including a proportional gain circuit, an integral gain circuit, a limit circuit, a gain booster circuit and a combiner. The gain circuits apply a proportional gain and an integral gain to an error signal, and the combiner combines both gained error signals to provide a control signal. The limit circuit applies a limit function that limits the proportional gain to a magnitude. The gain booster circuit increases gain while the limit function is being applied. The increased gain may be applied to only the integral gain, or to both the integral and proportional gains such as by boosting gain of the error signal. The apparatus may be a regulator that may include multiple control loops providing multiple error signals, in which a mode selector selects one of the error signals to control regulation. The limit function increases stability while the boosted gain improves transient response during mode transitions.

Abstract: A current mode control regulator including a control circuit and a current generator. The control circuit regulates an output voltage based on a reference voltage using current mode control. The current generator applies an adjust current to a feedback current signal, in which the adjust current is proportional to a difference between a voltage indicative of the output voltage and the reference voltage to emulate an AC load resistance at an output of the current mode regulator. A load resistor emulator emulates an AC load resistor to increase the phase margin of current mode control regulator when operating without a battery coupled to the output, such as when the battery is physically removed or otherwise electrically disconnected. Operation is not substantially changed when the battery is connected, so that the desired phase margin is achieve with or without the battery.

Abstract: Systems and methods for overcurrent protection in a battery charger are provided. For example, a method for overcurrent protection may include controlling a switching regulator to direct electrical current between the switching regulator and a battery port; sensing a voltage drop that is related to the electrical current passing between the switching regulator and the battery port; applying a first ramp voltage to the sensed voltage drop generating a modified sensed voltage drop; comparing the modified sensed voltage drop against at least one reference voltage; and when the modified sensed voltage drop exceeds the at least one reference voltage, changing operation of the switching regulator to protect the battery charger from an overcurrent state.

Abstract: A modulator for controlling a switch circuit of a voltage regulator, including a sense circuit that provides a current sense signal indicative of current through the output inductor, a ramp circuit that develops a ramp voltage on a ramp node using the current sense signal, an error circuit that develops an error signal indicative of output voltage error and that injects the error signal into the ramp node to adjust the ramp voltage, a comparator circuit that compares the ramp voltage with a fixed control voltage to develop a compare signal, and a logic circuit that uses the compare signal to develop a pulse control signal that controls the switch circuit. The output voltage error may be determined by comparing the output voltage with a reference voltage and converting the error voltage to a current applied to the ramp node.