User's Manual

SARA-G3 and SARA-U2 series - System Integration Manual
UBX-13000995 - R18 Advance Information Design-in
Page 98 of 206
C1
GND
C2 C4
SARA-U201
62
VCC
63
VCC
61
VCC
3V8
C5
+
SARA-U201
C5
GND plane
VCC line
Capacitor with
SRF ~900 MHz
FB1
C1 C3 C4
FB1
Ferrite Bead
for GHz noise
C2
C3
Capacitor with
SRF ~1900 MHz
Figure 45: Suggested schematic and layout design for the VCC line of SARA-U201 module; highly recommended when using an
integrated antenna
Reference Description Part Number - Manufacturer
C1
330 μF Capacitor Tantalum D_SIZE 6.3 V 45 m:
T520D337M006ATE045 - KEMET
C2
100 nF Capacitor Ceramic X7R 0402 10% 16 V
GRM155R71C104KA01 - Murata
C3
10 nF Capacitor Ceramic X7R 0402 10% 16 V
GRM155R71C103KA01 - Murata
C4
56 pF Capacitor Ceramic C0G 0402 5% 25 V
GRM1555C1E560JA01 - Murata
C5
15 pF Capacitor Ceramic C0G 0402 5% 25 V
GRM1555C1E150JA01 - Murata
FB1
Chip Ferrite Bead EMI Filter for GHz Band Noise
220 : at 100 MHz, 260 : at 1 GHz, 2000 mA
BLM18EG221SN1 - Murata
Table 27: Suggested components to reduce ripple / noise on VCC and to avoid undershoot/ overshoot on VCC voltage drops
ESD sensitivity rating of the VCC supply pins is 1 kV (Human Body Model according to JESD22-A114).
Higher protection level can be required if the line is externally accessible on the application board, e.g. if
accessible battery connector is directly connected to VCC pins. Higher protection level can be achieved by
mounting an ESD protection (e.g. EPCOS CA05P4S14THSG varistor array) close to accessible point.
2.2.1.7 Additional guidelines for VCC supply circuit design of SARA-G3 modules version “02” onward
SARA-G3 modules, versions “02” onwards, provide separate supply inputs over the VCC pins (see Figure 8):
x VCC pins #52 and #53: supply input for the internal RF power amplifier, demanding most of the total
current drawn of the module when RF transmission is enabled during a voice/data call
x VCC pin #51: supply input for the internal baseband PMU and transceiver, demanding minor current
SARA-G3 modules, versions “02” onwards, support two different extended operating voltage ranges: one for
the VCC pins #52 and #53, and another one for the VCC pin #51 (see the SARA-G3 series Data Sheet [1]).
All the VCC pins are in general intended to be connected to the same external power supply circuit, but separate
supply sources can be implemented for specific (e.g. battery-powered) applications considering that the voltage
at the VCC pins #52 and #53 can drop to a value lower than the one at the VCC pin #51, keeping the module
still switched-on and functional. Figure 46 describes a possible application circuit.
C1 C4
GND
C3C2 C5
SARA-G3 series
(except ‘00’, ‘01’ versions)
52
VCC
53
VCC
51
VCC
+
Li-Ion/Li-Pol
Battery
C6
SWVIN
SHDNn
GND
FB
C7
R1
R2
L1
U1
Step-up
Regulator
D1
C8
Figure 46: VCC circuit example with separate supply for SARA-G3 modules product version “02” onwards