Various applications may provide a conventional DC-to-DC buck converter that accepts a DC input voltage and produces a lower DC output voltage to drive at least one circuit component. Buck converters are typically used in low voltage applications requiring high amounts of load current (e.g., 30 amps or more). Typically, as shown in FIG. 19, a single phase buck converter 1900 includes a high-side switch 1905, a low-side switch 1910 connected to the high-side switch at a switch node 1915, an output inductor 1920 connected to the switch node 1915, and an output capacitor 1925 connected to the output inductor 1920.
In operation, the high-side and low-side switches 1905, 1910 are controlled by a control circuit 1930 to produce a desired output voltage across a load 1935. For this purpose, the high-side switch 1905 is initially switched on, while the low-side switch 1910 remains off. This causes a voltage drop across the output inductor 1920 of approximately (VIN−VOUT), which causes a current to build inside the output inductor 1920. At a subsequent time, the high-side switch 1905 is switched off, and the low-side switch 1910 is switched on. Since the current within the inductor 1920 cannot change instantly, sourced through switch 1910, the current continues to flow through the output inductor 1920, thereby charging the output capacitor 1925 and causing the voltage (VOUT) across the output capacitor 1925 to rise.
In this manner, the high-side and the low-side switches 1905, 1910 may be suitably switched at appropriate times, until the voltage (VOUT) across the output capacitor 1925 equals a desired output voltage, which is typically lower than the input voltage. Once the desired output voltage is reached, the high-side and the low-side switches 1905, 1910 may be periodically controlled so that the output inductor 1920 provides an amount of current equal to the current demand of a load 1935 connected across the output capacitor 1925. By providing no more and no less than the current demand of the load 1935, the voltage (VOUT) across the output capacitor 1925 remains at least approximately constant at the desired output voltage.
It is also known to provide a multi-phase DC-to-DC buck converter 2000 including a plurality of interleaving output phases 2005a, 2005b, 2005c, . . . , 2005n, as shown in FIG. 20. As shown in FIG. 20, each of the output phases 2005a, 2005b, 2005c, . . . , 2005n is assigned a respective switching arrangement, including a high-side switch, a low-side switch, and an output inductor. In operation, the control circuit 2010 periodically operates the output phases 2005a, 2005b, 2005c, . . . . , 2005n in a time-delayed sequence.
By operating the output phases 2005a, 2005b, 2005c, . . . , 2005n in a phase-delayed sequence, the conventional multi-phase buck converter 2000 distributes current production across the multiple output phases 2005a, 2005b, 2005c, . . . , 2005n, thereby distributing heat generation and reducing the requirements for the output capacitor 1925, such that a smaller output capacitor 125 may be utilized.
However, since conventional multi-phase buck converters require a fixed number of point-to-point connections between the control circuit 2010 and the output phases 2005a, 2005b, 2005c, . . . , 2005n, conventional multi-phase buck converters do not provide a robust architecture capable of easy expandability to include any number of desired phases.
Furthermore, conventional multi-phase buck converters do not optimally control the output voltage in response to a request for a lower desired output voltage or a decrease in current demand of the load 1935. By not optimally controlling the output voltage, conventional multi-phase buck converters may produce unwanted voltage spikes, which may damage circuitry connected to the output of the buck converter.