Datasheet

FUNCTIONAL DEVICE OPERATION
SUPPLIES
Analog Integrated Circuit Device Data
Freescale Semiconductor 87
MC13892
GEN1, GEN2, AND GEN3 REGULATORS
General purpose LDOs VGEN1, VGEN2, and VGEN3 are provided for expansion of the power tree to support peripheral
devices, which could include WLAN, BT, GPS, or other functional modules. All the regulators include programmable set points
for system flexibility. At the 1.2 V and 1.5 V set points, both VGEN1 and VGEN2 can be powered from an external buck regulator
(2.2
V typ) for an efficiency advantage, and reduced power dissipation in the pass devices. (Note that a connection to BP or the
external buck regulator as the input to the regulators is a hardwired board level commitment, and not changed on-the-fly).
VGEN3 has an internal PMOS pass FET which will support loads up to 50 mA. For higher current capability, drive for an
external PNP is provided. The external PNP configuration is offered to avoid excess on-chip power dissipation at high loads, and
large differential between BP and output settings. The input pin for the integrated PMOS option is shared with the base current
drive pin for the PNP option. The external PNP configuration must be committed as a hardwired board level implementation, while
the operating mode is selected through the VGEN3CONFIG bit after startup. The VGEN3 is not automatically enabled during the
power up sequence, allowing software to properly set the VGEN3CONFIG bit before the regulator is activated. The
recommended PNP device is the ON Semiconductor NSS12100XV6T1G, which is capable of handling up to 250
mW of
Table 57. VSD Voltage Control
Parameter Value Output Voltage ILoad max Input Supply
VSD[2:0]
000 1.80 V 250 mA BP or External Switcher
001 2.00 V 250 mA BP
010 2.60 V 250 mA BP
011 2.70 V 250 mA BP
100 2.80 V 250 mA BP
101 2.90 V 250 mA BP
110 3.00 V 250 mA BP
111 3.15 V 250 mA BP
Table 58. VGEN1 Control Register Bit Assignments
Parameter Value Function ILoad max
(75)
Input Supply
VGEN1[1:0]
00 output = 1.20 V 200 mA
BP or external
switcher
01 output = 1.50 V 200 mA
BP or external
switcher
10 output = 2.775 V 200 mA BP
11 output = 3.15 V 200 mA BP
Notes
75. The max load given for VGEN1MODE = 0 and must take into account the capabilities of the external pass device and operating
conditions, to manage its power dissipation. Load capability is 3.0
mA for VGEN1MODE = 1.
Table 59. VGEN2 Control Register Bit Assignments
Parameter Value Function ILoad max
(76)
Input Supply
VGEN2[2:0]
000 output = 1.20 V 350 mA
BP or external
switcher
001 output = 1.50 V 350 mA
BP or external
switcher
010 output = 1.60 V 350 mA BP
011 output = 1.80 V 350 mA BP
100 output = 2.70 V 350 mA BP
101 output = 2.80 V 350 mA BP
110 output = 3.00 V 350 mA BP
111 output = 3.15 V 350 mA BP
Notes
76. The max load is given for as VGEN2MODE = 0, and must take into account the capabilities of the external pass device and operating
conditions to manage its power dissipation. Load capability is 3.0
mA for VGEN2MODE = 1.