Abstract: A switch-mode DC/DC converter and a linear low drop out (LDO) DC/DC regulator are connected in parallel to drive a single load. Both regulators share a common voltage reference, feedback network, input supply and output such that the regulated voltage is identical during each mode of operation. During heavy loads the switch-mode regulator is in operation and the linear regulator is disabled for the highest efficiency possible. Conversely at light loads the linear regulator is in operation with the switch-mode regulator disabled, also maximizing the efficiency. Each regulator senses load current to automatically transition between the appropriate voltage regulators at fixed load current levels. The presented invention also includes a make before break transition scheme of the voltage regulators to minimize the voltage transients.

Abstract: A switch-mode DC/DC converter and a linear low drop out (LDO) DC/DC regulator are connected in parallel to drive a single load. Both regulators share a common voltage reference, feedback network, input supply and output such that the regulated voltage is identical during each mode of operation. During heavy loads the switch-mode regulator is in operation and the linear regulator is disabled for the highest efficiency possible. Conversely at light loads the linear regulator is in operation with the switch-mode regulator disabled, also maximizing the efficiency. Each regulator senses load current to automatically transition between the appropriate voltage regulators at fixed load current levels. The presented invention also includes a make before break transition scheme of the voltage regulators to minimize the voltage transients.

Abstract: A switch-mode DC/DC converter (101) and linear low drop out (LIDO) DC/DC regulator (105) are connected in parallel to drive a single load Both regulators share a common voltage reference, feedback network (103), input supply and output such that the regulated voltage is identical during each mode of operation. During heavy loads the switch-mode regulator (107) is in operation and the linear regulator is disabled for the highest efficiency possible. Conversely at light loads the linear regulator is in operation with the switch-mode regulator (107) disabled, also maximizing the efficiency. Each regulator senses load current (131) to automatically transition between the appropriate voltage regulators at fixed load current levels. The presented invention also includes a make before break transition scheme of the voltage regulators (103) to minimize the voltage transients.

Abstract: Methods and apparatus are disclosed for controlling switching regulators to automatically switch from a traditional pulse-width modulation (PWM) mode, when the load current is higher than a predetermined value, to a pulse-frequency modulation (PFM) mode, when the load current drops to a point lower than the predetermine value. Switching modes increases the efficiency of the regulator when the load current is low without provoking a large output voltage transient. In some embodiments, a single switching cycle regulates the output in the PFM mode, which reduces the switching losses and enhances the efficiency of the regulator.

Abstract: Methods and apparatus are disclosed for controlling switching regulators to automatically switch from a traditional pulse-width modulation (PWM) mode, when the load current is higher than a predetermined value, to a pulse-frequency modulation (PFM) mode, when the load current drops to a point lower than the predetermine value. Switching modes increases the efficiency of the regulator when the load current is low without provoking a large output voltage transient. In some embodiments, a single switching cycle regulates the output in the PFM mode, which reduces the switching losses and enhances the efficiency of the regulator.