User's Manual

System Overview and Functional Block Descriptions
1322x-LPB Reference Manual, Rev. 1.1
3-6 Freescale Semiconductor
Figure 3-6. 1322x-LPB PCB Bottom View
3.4.3 Optional Use of MC1322x Buck Regulator
The MC1322x is typically used in a single source, unregulated VCC configuration (VBATT connected in
parallel with LREG_BK_FB), and the 1322x-LPB
is supplied in this connection. However, the MC1322x
also has an optional buck switched regulator, and the 1322x-LPB supports use of the buck function.
Figure 3-7 shows the VCC connection at the MC1322x device. The PCB is supplied with the 0-ohm R66
component mounted, which is the simple non-regulated configuration. To allow use of the buck regulator:
• Remove R66
• Mount L2; an SMD power 100uH inductor, from manufacturer TDK # SLF6028T-101MR42-PF
(see Chapter 4, “Schematic, Board Layout, and Bill of Materials”).
• Mount C52; a 100 µF ceramic capacitor.
NOTE
Use of the buck converter requires proper initialization, control and support
through the application software. Refer to the
MC1322x Reference Manual.
Figure 3-7. MC1322x Main Power Connection
C59 and C60 Pads
Socket Pads
1
1
2
2
J16
TSM-102-01-L-SV
TP44
C52
10uF
Not Mounted
C8
100pF
TP45
Current Measurement
L2
100uH
Not Mounted
R65
0R
Not Mounted
VCC
R66
0R
C10
1uF
Not Mounted
VBATT
COIL_BK
LREG_BK_FB