MB3889 Fujitsu Microelectronics, Inc., MB3889 Datasheet - Page 27

• Manufacturer Part Number: MB3889
• Description: 2-channel Dc/dc Converter Ic With Overcurrent Protection Symmetrical-phase Type
• Manufacturer: Fujitsu Microelectronics, Inc.

SAMPLE CIRCUIT
6.2 k
3.3 k
430
120
VIN
10 k
10 k
Converter
R13
R10
R12
R16
R15
R17
AC/DC
(12 V)
Open : CH1 ON
L : CH1 OFF
VTH
Open : CH2 ON
L : CH2 OFF
VTH
A
B
0.01 F
0.1 F
0.1 F
13 k
13 k
0.022
0.022
1.4 V
1.4 V
C10
C11
C12
R14
C13
C14
R9
CSCP
CTL1
CTL2
INE1
INE2
CS1
CS2
F
F
FB1
FB2
11
14
15
13
10
2
1
3
9
CTL1
CTL2
10 A
H: at OVP
VREF
VREF
6 k
6 k
Buff
Buff
100
k
100
k
H
H
3 A
3 A
SCP Comp.
L priority
L priority
Latch2
Latch
S
CTL
CTL1
CTL2
R
H priority
Error
Amp2
CTL1
CTL2
1.23 V
1.38 V
1.23 V
1.38 V
CTL
Error
Amp1
OVP
Comp.1
VREF
UVLO
OVP
Comp.2
3.1 V
Latch1
S Q
R
L priority
L priority
OSC
5
RT
R8
47 k
H: at OVP
H: at OVP
H: at OCP
H: at SCP
H: UVLO
release
45 pF
Max Duty 81%
Max Duty 81%
PWM
Comp.2
Dtr
Dtr
PWM
Comp.1
3.0 V
1.8 V
3.0 V
1.8 V
CT1
CT2
6%
6%
H: OVP
3.5 V
H: at OVP
to Error amp reference
bias
Protection
Protection
8
Current
Current
VCC
Logic
Logic
VREF
C15
0.1 F
VREF
VB Reg.
24
1.23 V
OCP
Comp.2
OCP
Comp.1
118 A
118 A
CH1
CH2
L: at protection
operation
VR1
C16
0.1 F
Drv
Drv
Drv
Drv
7
1-1
2-1
1-2
2-2
SGND
ON/OFF
VCC
Power
CTL
5.1 V
22
30
29
28
27
26
25
16
17
18
19
20
23
12
21
4
6
ILIM2
N.C.
N.C.
CTL
OUT1-1
ILIM1
CB2
OUT1-2
VS2
VB
CB1
VS1
OUT2-1
1.3 k
OUT2-2
1.3 k
PWRGOOD
PGND1
PGND2
D1
R1
R5
D2
R4
100 k
H : ON (Power/CH6)
L : OFF (Standby mode)
VTH
Protection
control
signal
C9
4.7 F
C25 C18
82
C26 C17
82
F
F
1.4 V
C3 0.1 F
C6 0.1 F
0.1
0.1
F
F
Q1
Q2
MB3889
A
B
L1
L2
22
22
H
H
C4
C7
150
150
F
F
(2 V/10 A)
(5 V/5 A)
V
V
C5
0.1 F
C8
0.1 F
O
O
1
2
27