Integration Manual
SARA-R4/N4 series - System Integration Manual
UBX-16029218 - R13 Design-in Page 41 of 119
Figure 16 and the components listed in Table 9 show an example of a high reliability power supply circuit for the SARA-
R412M modules that support 2G radio access technology. This circuit is also suitable for the other SARA-R4/N4 series
modules, where the module VCC input is supplied by a step-down switching regulator capable of delivering the highest
peak / pulse current specified for the 2G use-case, with low output ripple and with fixed switching frequency in PWM
mode operation greater than 1 MHz.
SARA-R4/ N4
12V
C5
R3
C4
R2
C2C1
R1
VIN
RUN
VC
RT
PG
SYNC
BD
BOOST
SW
FB
GND
6
7
10
9
5
C6
1
2
3
8
11
4
C7
C8
D1
R4
R5
L1
C3
U1
52
VCC
53
VCC
51
VCC
GND
C9 C10 C11
Figure 16: Example of high reliability VCC supply circuit for SARA-R4/N4 series modules, using a step-down regulator
Reference Description Part Number - Manufacturer
C1 10 µF Capacitor Ceramic X7R 5750 15% 50 V Generic manufacturer
C2 10 nF Capacitor Ceramic X7R 0402 10% 16 V Generic manufacturer
C3 680 pF Capacitor Ceramic X7R 0402 10% 16 V Generic manufacturer
C4 22 pF Capacitor Ceramic C0G 0402 5% 25 V Generic manufacturer
C5 10 nF Capacitor Ceramic X7R 0402 10% 16 V Generic manufacturer
C6 470 nF Capacitor Ceramic X7R 0603 10% 25 V Generic manufacturer
C7
100 µF Capacitor Tantalum B_SIZE 20% 6.3V 15mΩ
T520B107M006ATE015 – Kemet
C8 100 nF Capacitor Ceramic X7R 16 V GRM155R71C104KA01 - Murata
C9 10 nF Capacitor Ceramic X7R 16 V GRM155R71C103KA01 - Murata
C10 68 pF Capacitor Ceramic C0G 0402 5% 50 V GRM1555C1E680JA01 - Murata
C11 15 pF Capacitor Ceramic C0G 0402 5% 50 V GRM1555C1E150JA01 - Murata
D1 Schottky Diode 40 V 3 A MBRA340T3G - ON Semiconductor
L1 10 µH Inductor 744066100 30% 3.6 A 744066100 - Wurth Electronics
R1
470 kΩ Resistor 0402 5% 0.1 W
Generic manufacturer
R2
15 kΩ Resistor 0402 5% 0.1 W
Generic manufacturer
R3
22 kΩ Resistor 0402 5% 0.1 W
Generic manufacturer
R4
390 kΩ Resistor 0402 1% 0.063 W
Generic manufacturer
R5
100 kΩ Resistor 0402 5% 0.1 W
Generic manufacturer
U1 Step-Down Regulator MSOP10 3.5 A 2.4 MHz LT3972IMSE#PBF - Linear Technology
Table 9: Components for high reliability VCC supply circuit for SARA-R4/N4 series modules, using a step-down regulator
☞
☞☞
☞
See the section 2.2.1.10, and in particular Figure 27 / Table 19, for the parts recommended to be provided if the
application device integrates an internal antenna.