
TOBY-R2 series - System integration manual
UBX-16010572 - R10
Design-in
Page 72 of 151
C2
GND
C3
C4
TOBY-R2 series
71
VCC
72
VCC
70
VCC
C1
C5
3V8
+
Recommended for
cellular modules
supporting 2G
Figure 32: Suggested schematic for the VCC bypass capacitors to reduce ripple / noise on supply voltage profile
Reference
Description
Part Number - Manufacturer
C1
15 pF Capacitor Ceramic C0G 0402 5% 50 V
GRM1555C1H150JA01 - Murata
C2
68 pF Capacitor Ceramic C0G 0402 5% 50 V
GRM1555C1H680JA01 - Murata
C3
10 nF Capacitor Ceramic X7R 0402 10% 16 V
GRM155R71C103KA01 - Murata
C4
100 nF Capacitor Ceramic X7R 0402 10% 16 V
GRM155R71C104KA01 - Murata
C5
330
µ
F Capacitor Tantalum D_SIZE 6.3 V 45 m
T520D337M006ATE045 - KEMET
Table 24: Suggested components to reduce ripple / noise on VCC
☞
The necessity of each part depends on the specific design, but it is recommended to provide all
the bypass capacitors described in
if the application device integrates an
internal antenna.
☞
ESD sensitivity rating of the VCC supply pins is 1 kV (HBM 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 the supply pins. Higher protection level can
be achieved by mounting an ESD protection (e.g. EPCOS CA05P4S14THSG varistor) close to
accessible point.
2.2.1.7
Additional guidelines for VCC supply circuit design of TOBY-R200 modules
TOBY-R200 modules provide separate supply inputs over the VCC pins (see
VCC pins #71 and #72 represent the 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
VCC pin #70 represents the supply input for the internal baseband Power Management Unit and
the internal transceiver, demanding minor part of the total current drawn of the module when RF
transmission is enabled during a voice/data call
TOBY-R200 support two different extended operating voltage ranges: one for the VCC pins #71 and
#72, and another one for the VCC pin #70 (see the TOBY-R2 series data sheet
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 #71 and #72 can drop to a value lower than the one at the
VCC pin #70, keeping the module still switched-on and functional.
application circuit.