Ublox TOBY-R2 Series, Руководство по системной интеграции

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TOBY-R2 series - System integration manual
UBX-16010572 - R10 Design-in Page 74 of 151
The L6924U, as linear charger, is more suitable for applications where the charging source has a
relatively low nominal voltage (~5 V), so that a switching charger is suggested for applications where
the charging source has a relatively high nominal voltage (e.g. ~12 V, see the following section
2.2.1.9
for specific design-in).
C5 C8 C7 C6 C9
GND
TOBY-R2 series
71
VCC
72
VCC
70
VCC
+
USB
Supply
C3 R4
θ
U1
I
USB
I
AC
I
END
T
PRG
SD
V
IN
V
INSNS
MODE
ISEL
C2 C1
5V0
TH
GND
V
OUT
V
OSNS
V
REF
R1
R2
R3
Li-Ion/Li-Pol
Battery Pack
D1
B1
C4
Li-Ion/Li-Polymer
Battery Charger IC
D2
Figure 34: Li-Ion (or Li-Polymer) battery charging application circuit
Reference Description Part Number - Manufacturer
B1 Li-Ion (or Li-Polymer) battery pack with 470  NTC Various manufacturer
C1, C4 1
µ
F Capacitor Ceramic X7R 0603 10% 16 V GRM188R71C105KA12 - Murata
C2, C6 10 nF Capacitor Ceramic X7R 0402 10% 16 V GRM155R71C103KA01 - Murata
C3 1 nF Capacitor Ceramic X7R 0402 10% 50 V GRM155R71H102KA01 - Murata
C5
330
µ
F Capacitor Tantalum D_SIZE 6.3 V 45 m
 T520D337M006ATE045 - KEMET
C7 100 nF Capacitor Ceramic X7R 0402 10% 16 V GRM155R61A104KA01 - Murata
C8 68 pF Capacitor Ceramic C0G 0402 5% 50 V GRM1555C1H680JA01 - Murata
C9 15 pF Capacitor Ceramic C0G 0402 5% 50 V GRM1555C1H150JA01 - Murata
D1, D2 Low Capacitance ESD Protection CG0402MLE-18G - Bourns
R1, R2 24 k  Resistor 0402 5% 0.1 W RC0402JR-0724KL - Yageo Phycomp
R3
3.3 k  Resistor 0402 5% 0.1 W
RC0402JR-073K3L - Yageo Phycomp
R4 1.0 k  Resistor 0402 5% 0.1 W RC0402JR-071K0L - Yageo Phycomp
U1 Single Cell Li-Ion (or Li-Polymer) Battery Charger IC L6924U - STMicroelectronics
Table 26: Suggested components for Li-Ion (or Li-Polymer) battery charging application circuit
2.2.1.9 Guidelines for battery charging and power path management circuit
Application devices where both a permanent primary supply / charging source (e.g. ~12 V) and a
rechargeable back-up battery (e.g. 3.7 V Li-Pol) are available at the same time as possible supply
source should implement a suitable charger / regulator with integrated power path management
function to supply the module and the whole device while simultaneously and independently charging
the battery.
Figure 35 reports a simplified block diagram circuit showing the working principle of a charger /
regulator with integrated power path management function. This component allows the system to be
powered by a permanent primary supply source (e.g. ~12 V) using the integrated regulator which
simultaneously and independently recharges the battery (e.g. 3.7 V Li-Pol) that represents the back-
up supply source of the system: the power path management feature permits the battery to
supplement the system current requirements when the primary supply source is not available or
cannot deliver the peak system currents.