Shared-bus current sharing parallel connected current-mode DC to DC converters

DETAILED DESCRIPTION An object of the invention is to provide uniform current distribution, stiff regulation of the system output voltage, and reduced output impedance variances of a power supply system.
Another object of the invention is to provide current-mode controlled converters in a power system using a shared-bus providing a common error signal to the converters all equally controlled for supplying an equal contribution of a load current supplied to a load.
The present invention employs current-mode control through a peak current approach using a shared-bus connected to a plurality of individual DC to DC converters.
In this peak current approach, each converter power stage operates as a voltage-controlled current source as a current-mode power stage.
A voltage regulation control circuit is modified to select the error voltage generated from the control loop that has the smallest reference voltage or as desired the highest reference voltage.
This error voltage is then used as a common commanding control signal communicated through the shared-bus for all current-mode power stages.
This shared-bus configuration offers near-uniform current sharing.
Additionally, the DC or low frequency gain of the voltage regulation control loop can be made much higher to provide a stiff regulated DC output voltage without degrading current sharing performance.
This control scheme regulates the output voltages of all paralleled converters to the same voltage corresponding to the smallest reference voltage or if desired, the highest reference voltage, within the converter system.
The shared-bus is used to achieve near-uniform current distribution, small variances in the system output impedance, highly regulated system output voltage, and fast transient output performance.
The power system is for supplying power to load.
The system comprises a plurality of parallel connected current-mode power stages that share the common control signal from respective shared-bus control ports.
Each of the plurality of current-mode power stages is for converting an input voltage to a regulated output voltage coupled to the load