MB3878 Datasheet, PDF (19/24 Pages) Fujitsu Component Limited. – DC/DC Converter IC for Charging

MB3878
s REFERENCE DATA
Conversion efficiency vs. charge current
(Fixed voltage mode)
100
VIN = 19 V
98
BATT charge voltage = 12.6 V fOSC = 277.9 kHz
96
η (%) = (VBATT × IBATT) / (VIN × IIN) × 100
94
92
90
88
86
84
82
80
10 m
100 m
1
10
BATT charge current IBATT (A)
Conversion efficiency vs. charge voltage
(Fixed current mode)
100
VIN = 19 V
98
BATT : Electronic load,
96
(Product of KIKUSUI PLZ-150W)
94
92
90
88
86
84
82
80
0 2 4 6 8 10 12 14 16
BATT charge voltage VBATT (V)
BATT voltage vs. BATT charge current
18
VIN = 19 V
16
BATT : Electronic load,
14
(Product of KIKUSUI PLZ-150W)
12
10 _{Dead Battery MODE}
8
DCC MODE
6
4
2
DCC : Dynamically Controlled Charging
0
0
1
2
3
4
5
BATT charge current IBATT (A)
Soft start operating waveforms
BATT (V)
VIN = 19 V
Load : BATT = 20 Ω
−INE2 = 0 V
20
15
5V
CTL (V) ¹⁰
20 5
15 0
10
5
0
5V
20 ms
0
40 80 120 160 200
t (ms)
DC/DC converter switching waveforms
OUTH (V)
20
15
5V
10
5
0
VIN = 19 V
fOSC = 277.9 kHz
Load : BATT = 1 A
FB3 (V)
4
2
0
2V
1 µs
0
2
4
6
8
10
t (µs)
19