SLVSCO4D July 2015 – February 2019 TPS65917-Q1
One-time programmable (OTP) bits define the default output voltage and enabling of the regulator during the start-up sequence.
After start up, while the SMPS is in forced PWM mode, software can change the output voltage by setting the RANGE and VSEL bits in the SMPSx_VOLTAGE register. When the SMPS enters ECO mode, the output voltage cannot be changed. Setting the SMPSx_VOLTAGE.VSEL register to 0x0 disables the SMPS (turns off). The value for the RANGE bit cannot be changed when the SMPS is active. To change the operating voltage range, the SMPS must be disabled.
The operating mode (ECO, forced PWM, or off) of an SMPS when the TPS65917-Q1 device is in ACTIVE state can be selected in the SMPSx_CTRL register by setting the MODE_ACTIVE[1:0] bit field.
The operating mode of an SMPSx when the TPS65917-Q1 device is in the SLEEP state is controlled by the MODE_SLEEP[1:0] bit field, depending on the SMPS assignment to the NSLEEP, ENABLE1, and ENABLE2 pins (see Table 5-5).
The soft-start slew rate (t(ramp)) is fixed.
The pulldown discharge resistance for off mode is enabled and disabled in the SMPS_PD_CTRL register. By default, discharge is enabled. Two pulldown resistors, one at SMPSx_SW and one at SMPS_FDBK node, are enabled or disabled together. For multiphase SMPS, pulldown is in the master phase.
SMPS behavior for warm reset (reload default values or keep current values) is defined by the SMPSx_CTRL.WR_S bit.