SARA-R4 series - System Integration Manual
UBX-16029218 - R06
Design-in
Page 37 of 102
Figure 11 and Table 9 show an example of a high reliability power supply circuit, where the module
VCC
input is
supplied by a step-down switching regulator capable of delivering maximum current with low output ripple and
with fixed switching frequency in PWM mode operation greater than 1 MHz.
12V
C2
C1
VCC
EN
PG
VSW
GND
8
9
1
4
2
D1
R1
R2
L1
U1
BST
FB 5
SARA-R4
52
VCC
53
VCC
51
VCC
GND
3V8
C6
C7
C8
PGND
C4
C3
C5
11
10
C9
Figure 11: Example of high reliability VCC supply application circuit using a step-down regulator
Reference
Description
Part Number - Manufacturer
C1
10 µF Capacitor Ceramic X7R 50 V
Generic manufacturer
C2
10 nF Capacitor Ceramic X7R 16 V
Generic manufacturer
C3
22 nF Capacitor Ceramic X7R 16 V
Generic manufacturer
C4
22 µF Capacitor Ceramic X5R 25 V
Generic manufacturer
C5
22 µF Capacitor Ceramic X5R 25 V
Generic manufacturer
C6
15 pF Capacitor Ceramic C0G 0402 5% 50 V
Generic manufacturer
C7
68 pF Capacitor Ceramic C0G 0402 5% 50 V
Generic manufacturer
C8
10 nF Capacitor Ceramic X7R 16 V
Generic manufacturer
C9
100 nF Capacitor Ceramic X7R 16 V
Generic manufacturer
D1
Schottky Diode 30 V 2 A
MBR230LSFT1G - ON Semiconductor
L1
4.7 µH Inductor 20% 2 A
SLF7045T-4R7M2R0-PF - TDK
R1
470 k
Resistor 0.1 W
Generic manufacturer
R2
150 k
Resistor 0.1 W
Generic manufacturer
U1
Step-Down Regulator 1 A 1 MHz
TS30041 - Semtech
Table 9: Components for high reliability VCC supply application circuit using a step-down regulator