FUJITSU MB3878 - Manual (Page 20)

MB3878
20
■ ■ ■ ■ APPLICATION EXAMPLE 2
+ −
− +
8 10 13 12
A B
C D
9
+ −
+ −
+ −
− +
4 2 24 1 3
Ч 25 Ч 25
+ + + −
5
20 21 19
− + +
+ −
11 16 22
17
6
23
14 18
<Current Amp.1>
<Error Amp.1>
7
VREF
<Current Amp.2>
<Error Amp.2>
VREF
<Error Amp.3>
VREF
VREF
VREF 5.0 V
4.2 V
1
µ A
15
<SOFT>
2.5 V 1.5 V
<OUT>
<UVLO>
<OSC>
Bias
Voltage
<VH>
<REF>
<CTL>
<PWM Comp.>
Drive
V
CC
(V
CC
− 5 V)
(VCC UVLO)
VCC
VCC
VCC CTL
215 k
Ω
35 k
Ω
0.91 V
(0.77 V)
VREF UVLO
bias
− INC2
OUTD
FB2
VREF
− INE2 + INE2 + INE1 FB1
OUTC1
− INE1 − INC1
+ INC2
GND
CS
VCC (O) OUT
Q1
Output voltage (Battery voltage) is adjustable
D1
Battery
VH
RT
− INE3
FB3
+ INC1
(45 pF)
R8 100 k
Ω
C10
5600 pF
+ −
+ −
+ −
R9
10 k
Ω
R14 1.3 k
Ω
R10
24 k
Ω
R11
36 k
Ω
R7
22 k
Ω
R18
200 k
Ω
R17 100 k
Ω
C
S
2200 pF
R3
330 k
Ω
R
T
47 k
Ω
C9 0.1
µ F
C7 0.1
µ F
C5
0.1
µ F
C2
100
µ F
C3 100
µ F
C1 22
µ F
R
S
1
0.033
Ω
R
S
2
0.033
Ω
L1
12
µ H
R22
100 k
Ω
R21
100 k
Ω
R19
100 k
Ω
R20
100 k
Ω
R15
110
Ω
R16
200 k
Ω
Q2
A(1/2)
A(2/2)
SW
VIN
VIN
Note : SW ON : Differential Charging MODE
R12
30 k
Ω
R13
30 k
Ω
C8
10000 pF
A
B
C
D
System
AC Adaptor
VIN
BATT
OUTC2
R23
100 k
Ω
C6
1500 pF
SW OFF : Dead Battery MODE Range of input voltage VIN = 13V to 21V(at Load = 3A)