6.3.2.1.5 DVS-Capable Regulators
The step-down converters SMPS12 or SMPS123, SMPS45 or SMPS457, SMPS6, and SMPS8 are DVS-capable and have some additional parameters for control. The slew rate of the output voltage during voltage level change is fixed at 2.5 mV/µs. The control for two different voltage levels (ROOF and FLOOR) with the NSLEEP and ENABLE1 signals is available. When the ROOF_FLOOR control is not used, two different voltage levels can be selected with the CMD bit in the SMPSx_FORCE register.
- The output voltage slew rate for achieving new output voltage value is fixed at 2.5 mV/μs.
- The NSLEEP and ENABLE1 terminals can be used for roof-floor control of SMPS. For roof-floor operation sets the SMPSx_CTRL.ROOF_FLOOR_EN register, and assign SMPS to NSLEEP and ENABLE1 in the NSLEEP_SMPS_ASSIGN and ENABLE1_SMPS_ASSIGN registers. When the controlling terminal is active, the SMPS output value is defined by the SMPSx_VOLTAGE register. When the controlling terminal is not active, the SMPS output value is defined by the SMPSx_FORCE register.
- Set the second value for the output voltage with the SMPSx_FORCE.VSEL register. A value of 0x0 disables the SMPS (OFF).
- Select which register, SMPSx_VOLTAGE or SMPSx_FORCE, to use with the SMPSx_FORCE.CMD bit. The default is the voltage setting of SMPSx_VOLTAGE. For the CMD bit to work, ensure that SMPSx_CTRL.ROOF_FLOOR_EN = 0.
Figure 6-5 shows the SMPS controls for DVS.