MMPF0100NPEP Datasheet, PDF (79/137 Pages) Freescale Semiconductor, Inc – Four to six buck converters, depending on configuration

Functional Block Requirements and Behaviors
Power Generation
6.4.5 Boost Regulator
SWBST is a boost regulator with a programmable output from 5.0 to 5.15 V. SWBST can supply the VUSB regulator for the USB
PHY in OTG mode, as well as the VBUS voltage. Note that the parasitic leakage path for a boost regulator will cause the
SWBSTOUT and SWBSTFB voltage to be a Schottky drop below the input voltage whenever SWBST is disabled. The switching
NMOS transistor is integrated on-chip. Figure 23 shows the block diagram and component connection for the boost regulator.
VIN
CINBST
LBST ^SWBSTIN
VOBST ^DBST
SWBSTLX
Driver
SWBSTMODE
EP
RSENSE
OC
VREFSC
SC
VREFUV
UV
Controller
SWBSTFAULT
I²C
Interface
COSWBST
SWBSTFB
Internal
Compensation _Z2
Z1
EA
VREF
Figure 23. Boost Regulator Architecture
6.4.5.1 SWBST Setup and Control
Boost regulator control is done through a single register SWBSTCTL described in Table 86. SWBST is included in the power-up
sequence if its OTP power-up timing bits, SWBST_SEQ[4:0], are not all zeros.
Table 86. Register SWBSTCTL - ADDR 0x66
Name
SWBST1VOLT
SWBST1MODE
UNUSED
SWBST1STBYMODE
Bit #
1:0
3:2
4
6:5
R/W Default
Description
Set the output voltage for SWBST
00 = 5.000 V
R/W
0x00
01 = 5.050 V
10 = 5.100 V
11 = 5.150 V
Set the Switching mode on Normal operation
00 = OFF
R
0x02
01 = PFM
10 = Auto (Default)⁽⁵³⁾
11 = APS
–
0x00 UNUSED
Set the Switching mode on Standby
00 = OFF
R/W
0x02
01 = PFM
10 = Auto (Default)⁽⁵³⁾
11 = APS
Analog Integrated Circuit Device Data
Freescale Semiconductor
PF0100
79