FUNCTIONAL DEVICE OPERATION
SUPPLIES
Table 47. Buck Switchers (SW1, 2, 3, 4) Output Voltage Programmability
Set point
29
SWx[4:0]
SWx Output, SWxHI = 0 (Volts)
SWx Output (59), SWxHI = 1 (Volts)
11101
11110
11111
1.325
1.350
1.375
1.825
1.850
1.850
30
31
59. Output range not available for SW1. SW1 output range is 0.600-1.375, therefore SW1HI = 1 does not apply to SW1. The SW1HI bit
should always be set to 0.
Since the startup default values of the buck switchers are dependent on the state of the PUMS pin, the SWxHI bit settings will
likewise be determined by the PUMS pin. The settings are aligned to the likely application ranges for use cases as given in the
Defaults tables in Power Control System. The following tables define the SWxHI bit states after a startup event is completed, but
can be reconfigured via the SPI if desired, if an alternate range is needed. Care should be taken when changing SWxHI bit to
avoid unintended jumps in the switcher output. The SWxHI setting applies to Normal, Standby, and DVS set points for the
corresponding switcher.
Table 48. SWxHI States for Power Up Defaults
PUMS1
PUMS2
SW1HI
SW2HI
SW3HI
SW4HI
Ground
Open
VCOREDIG
VCORE
Ground
Open
Open
Open
Open
Open
Ground
Ground
0
0
0
1
0
0
0
1
0
0
0
1
0
0
0
1
0
1
1
1
0
1
1
1
Note that the following efficiency curves were measured with the MC13892 in a socket.
13892
Analog Integrated Circuit Device Data
Freescale Semiconductor
75
FREESCALE [ Freescale ]
