MB3889 Fujitsu Microelectronics, Inc., MB3889 Datasheet - Page 5

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

BLOCK DIAGRAM
Open : CH1 ON
L : CH1 OFF
VTH
Open : CH2 ON
L : CH2 OFF
VTH
1.4 V
1.4 V
CSCP
CTL1
CTL2
INE1
INE2
CS1
CS2
FB1
FB2
14
15
13
10
11
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
1.23 V
1.38 V
Error
Amp2
1.23 V
1.38 V
CTL1
CTL2
CTL
Error
Amp1
OVP
Comp.1
VREF
UVLO
OVP
Comp.2
3.1 V
Latch1
S Q
R
L priority
L priority
RT
OSC
5
H: at OVP
H: at OCP
H: at OVP
H: at SCP
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: at OCP
3.5 V
H: at
UVLO release
H: at OCP
to Error amp reference
VREF
bias
Protection
Protection
8
Current
Current
Logic
Logic
VREF
VB Reg.
VCC
24
1.23 V
OCP
Comp.2
OCP
Comp.1
118 A
118 A
SGND
CH1
CH2
VR1
L: at protection
operation
Drv
1-1
Drv
2-1
Drv
1-2
Drv
2-2
7
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
PWRGOOD
H : ON (Power On)
L : OFF (Standby mode)
VTH
N.C.
N.C.
CTL
VB
CB1
OUT1-1
VS1
OUT2-1
PGND1
ILIM1
CB2
OUT1-2
VS2
OUT2-2
PGND2
ILIM2
Protection
control
signal
1.4 V
MB3889
5