The TPS40090 is a two-, three-, or four-phase programmable synchronous buck controller that is optimized for low-voltage, high-current applications powered by a 5-V to 15-V distributed supply. A multi-phase converter offers several advantages over a single power stage including lower current ripple on the input and output capacitors, faster transient response to load steps, improved power handling capabilities, and higher system efficiency.

Each phase can be operated at a switching frequency up to 1-MHz, resulting in an effective ripple frequency of up to 4-MHz at the input and the output in a four-phase application. A two-phase design operates 180° out of phase, a three-phase design operates 120° out of phase, and a four-phase design operates 90° out of phase, as shown in Figure 1.

The number of phases is programmed by connecting the deactivated phase PWM output to the output of the internal 5-V LDO. In two-phase operation the even phase outputs should be deactivated.Read more