TOBY-L1 and MPCI-L1 series - System Integration Manual
UBX-13001482 - R04
Advance Information
Design-in
Page 39 of 90
Figure 20 and the components listed in Table 11 show an example of a high reliability power supply circuit,
where the module
VCC
or
3.3Vaux
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.
It is suggested to configure the switching regulator to generate a voltage supply value slightly below the
maximum limit of the module
VCC
or
3.3Vaux
normal operating range (e.g. ~4.1 V for
VCC
and ~3.44 V for
the
3.3Vaux
, as in the circuit described in Figure 20 and Table 11). This reduces the power on the linear
regulator and improves the thermal design of the circuit.
12V
C5
R3
C4
R2
C2
C1
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
TOBY-L1 series
71
VCC
72
VCC
70
VCC
GND
12V
C5
R3
C4
R2
C2
C1
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
R6
R5
L1
C3
U1
MPCI-L1 series
24
3.3Vaux
39
3.3Vaux
2
3.3Vaux
GND
41
3.3Vaux
52
3.3Vaux
Figure 20: Suggested schematic design for the VCC and 3.3Vaux voltage supply application circuit using a step-down regulator
Reference
Description
Part Number - Manufacturer
C1
10 µF Capacitor Ceramic X7R 5750 15% 50 V
C5750X7R1H106MB - TDK
C2
10 nF Capacitor Ceramic X7R 0402 10% 16 V
GRM155R71C103KA01 - Murata
C3
680 pF Capacitor Ceramic X7R 0402 10% 16 V
GRM155R71H681KA01 - Murata
C4
22 pF Capacitor Ceramic C0G 0402 5% 25 V
GRM1555C1H220JZ01 - Murata
C5
10 nF Capacitor Ceramic X7R 0402 10% 16 V
GRM155R71C103KA01 - Murata
C6
470 nF Capacitor Ceramic X7R 0603 10% 25 V
GRM188R71E474KA12 - Murata
C7
22 µF Capacitor Ceramic X5R 1210 10% 25 V
GRM32ER61E226KE15 - Murata
C8
330 µF Capacitor Tantalum D_SIZE 6.3 V 45 m
Ω
T520D337M006ATE045 - KEMET
D1
Schottky Diode 40 V 3 A
MBRA340T3G - ON Semiconductor
L1
10 µH Inductor 744066100 30% 3.6 A
744066100 - Wurth Electronics
R1
470 k
Ω
Resistor 0402 5% 0.1 W
2322-705-87474-L - Yageo
R2
15 k
Ω
Resistor 0402 5% 0.1 W
2322-705-87153-L - Yageo
R3
22 k
Ω
Resistor 0402 5% 0.1 W
2322-705-87223-L - Yageo
R4
430 k
Ω
Resistor 0402 5% 0.063 W
RC0402JR-07430KL - Yageo
R5
100 k
Ω
Resistor 0402 5% 0.1 W
2322-705-70104-L - Yageo
U1
Step-Down Regulator MSOP10 3.5 A 2.4 MHz
LT3972IMSE#PBF - Linear Technology
Table 11: Suggested components for the VCC / 3.3Vaux supply application circuit using a step-down regulator