ZHCSKK3B December 2019 – February 2022 TPS6594-Q1
PRODUCTION DATA
The 4-phase converters (BUCK1, BUCK2, BUCK3, and BUCK4) switches each channel 90° apart under heavy load conditions. As a result, the 4-phase converter has an effective ripple frequency four times greater than the switching frequency of any one phase. In the same way, 3-phase converter has an effective ripple frequency three times greater and 2-phase converter has an effective ripple frequency two times greater than the switching frequency of any one phase; the parallel operation, however, decreases the efficiency at light load conditions. The TPS6594-Q1 can change the number of active phases to optimize efficiency for the variations of the load in order to overcome this operational inefficiency. The process in which the multi-phase buck regulator in case of increasing load current automatically increases the number of active phases is called phase adding. The process in which the multi-phase buck regulator in case of decreasing load current automatically decreases the number of active phases is called phase shedding. The concept is shown in Figure 8-4.
The converter can be forced to multi-phase operation by the BUCKn_FPWM_MP bit in BUCKn_CTRL1 register. If the regulator operates in forced multi-phase mode , each phase automatically operates in the forced-PWM mode. If the multi-phase operation is not forced, the number of phases are added and shed automatically to follow the required output current.