Ublox SARA-R422

SARA-R4 series - System integration manual
UBX-16029218 - R20 Design-in Page 54 of 128
C1-Public
2.2.1.8 Guidelines for particular VCC supply circuit design for SARA-R4x2
The SARA-R412M, SARA-R422, SARA-R422S and SARA-R422M8S modules, supporting 2G radio
access technology, have separate supply inputs over the VCC pins (see Figure 6):
• 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 call
• VCC pin #51: supply input for the internal power management unit, baseband and transceiver
parts, demanding minor current
Generally, all the VCC pins are 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. 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 29 illustrates a possible application
circuit.
C1 C4
GND
C3C2 C5
SARA-R412M
SARA-R422 /-R422S /-R422M8S
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 29: VCC circuit example with separate supply for SARA-R412M, SARA-R422, SARA-R422S, SARA-R422M8S modules
Reference
Description
Part Number - Manufacturer
C1
100 µF Capacitor Tantalum B_SIZE 20% 6.3V 15m
T520B107M006ATE015 – Kemet
C2
100 nF Capacitor Ceramic X7R 0402 10% 16 V
GRM155R61A104KA01 - 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
C6
10 µF Capacitor Ceramic X5R 0603 20% 6.3 V
GRM188R60J106ME47 - Murata
C7
22 µF Capacitor Ceramic X5R 1210 10% 25 V
GRM32ER61E226KE15 - Murata
C8
10 pF Capacitor Ceramic C0G 0402 5% 25 V
GRM1555C1E100JA01 - Murata
D1
Schottky Diode 40 V 1 A
SS14 - Vishay General Semiconductor
L1
10 µH Inductor 20% 1 A 276 m
SRN3015-100M - Bourns Inc.
R1
1 M Resistor 0402 5% 0.063 W
Generic manufacturer
R2
412 k Resistor 0402 5% 0.063 W
Generic manufacturer
U1
Step-up Regulator 350 mA
AP3015 - Diodes Incorporated
Table 18: Examples of parts for the VCC circuit with separate supply for SARA-R412M /-R422 /-R422S /-R422M8S modules
☞ See the section 2.2.1.10, and in particular Figure 31 / Table 20, for the parts recommended to be
provided if the application device integrates an internal antenna.