u-blox LARA-R2 series System Integration Manual page 76


Fast-charge constant current: the battery is charged with the maximum current, configured by the value
of an external resistor to a value suitable for the application

Constant voltage: when the battery voltage reaches the regulated output voltage (4.2 V), the current is
progressively reduced until the charge termination is done. The charging process ends when the charging
current reaches the 10% of the fast-charge current or when the charging timer reaches the value configured
by an external capacitor
Using a battery pack with an internal NTC resistor, the MP2617 can monitor the battery temperature to protect
the battery from operating under unsafe thermal conditions.
Several parameters as the charging current, the charging timings, the input current limit, the input voltage limit,
the system output voltage can be easily set according to the specific application requirements, as the actual
electrical characteristics of the battery and the external supply / charging source: proper resistors or capacitors
have to be accordingly connected to the related pins of the IC.
Li-Ion/Li-Polymer Battery
Charger / Regulator with
Power Path Managment
12V
Primary
VIN
Source
R4
VLIM
R5
EN
R1
ILIM
R2
ISET
TMR
AGND
C1 C2
U1
Figure 34: Li-Ion (or Li-Polymer) battery charging and power path management application circuit
Reference Description
B1 Li-Ion (or Li-Polymer) battery pack with 10 k NTC
C1, C5, C6 22 µF Capacitor Ceramic X5R 1210 10% 25 V
C2, C4, C11 100 nF Capacitor Ceramic X7R 0402 10% 16 V
C3 1 µF Capacitor Ceramic X7R 0603 10% 25 V
C7, C13 68 pF Capacitor Ceramic C0G 0402 5% 50 V
C8, C14 15 pF Capacitor Ceramic C0G 0402 5% 25 V
C9, C15 8.2 pF Capacitor Ceramic C0G 0402 5% 50 V
C10
330 µF Capacitor Tantalum D_SIZE 6.3 V 45 m
C12 10 nF Capacitor Ceramic X7R 0402 10% 16 V
D1, D2 Low Capacitance ESD Protection
R1, R3, R5
10 k Resistor 0402 5% 1/16 W
R2 1.0 k Resistor 0402 5% 0.1 W
R4 22 k Resistor 0402 5% 1/16 W
L1
1.2 µH Inductor 6 A 21 m 20%
U1 Li-Ion/Li-Polymer Battery DC/DC Charger / Regulator
with integrated Power Path Management function
Table 26: Suggested components for Li-Ion (or Li-Polymer) battery charging and power path management application circuit
UBX-16010573 - R02
BST
C4
L1
SW
SYS
C5
BAT
NTC
VCC
R3
C3 C6 C7 C8
PGND
Objective Specification
LARA-R2 series - System Integration Manual
Li-Ion/Li-Pol
Battery Pack
+
C10
θ
C9
B1
D1 D2
Part Number - Manufacturer
Various manufacturer
GRM32ER61E226KE15 - Murata
GRM155R61A104KA01 - Murata
GRM188R71E105KA12 - Murata
GRM1555C1H680JA01 - Murata
GRM1555C1E150JA01 - Murata
GRM1555C1H8R2DZ01 - Murata
T520D337M006ATE045 - KEMET
GRM155R71C103KA01 - Murata
CG0402MLE-18G - Bourns
RC0402JR-0710KL - Yageo Phycomp
RC0402JR-071K0L - Yageo Phycomp
RC0402JR-0722KL - Yageo Phycomp
7447745012 - Wurth
MP2617 - Monolithic Power Systems (MPS)
LARA-R2 series
VCC
51
VCC
52
VCC
53
C11 C12 C13 C14 C15
GND
Design-in
Page 76 of 148