DS04-27220-4E
FUJITSU SEMICONDUCTOR
DATA SHEET
ASSP For Power Supply Applications
6-ch DC/DC Converter IC
With Synchronous Rectifier
MB3825A
s
DESCRIPTION
The MB3825A is a pulse width modulation (PWM) type 6-channel DC/DC converter IC with synchronous rectifi-
cation (2-channels) designed for low voltage, high efficiency operation in high precision and high frequency
applications, ideal for down conversion.
The MB3825A is an ideal device offering low power consumption, compact size and light weight for products such
as self-contained camcorders and digital still cameras.
This product is covered by US Patent Number 6,147,477.
s
FEATURES
· Synchronous rectification (channels 1 and 4)
· High efficiency drive with power-on output enhanced by built-in speed-up circuit
· Wide range of operating power supply voltage : 2.5 V to 12 V
· Built-in high-precision reference voltage generator : 1.5 V
±
1
%
· Wide operating oscillator frequency range, high frequency capability : 50 kHz to 800 kHz
· Wide input voltage range (all channels) : 0 V to Vcc
-
0.9 V
· Error amplifier output for soft-start (channels 1, 2, 4) (All channels may be set for same soft-start time regardless
of duty factor setting.)
s
PACKAGE
64-pin plastic LQFP
64-pin plastic LQFP
(FPT-64P-M03)
(FPT-64P-M20)
MB3825A
2
s
PIN ASSIGNMENT
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
CB2-5
CB1-5
VB5
OUT1-6
CB2-6
CB1-6
VB6
OVP5
,
6
IN (C) 6
+
IN (E) 6
-
IN (E) 6
FB6
SCP
IN (C) 5
+
IN (E) 5
-
IN (E) 5
48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
CB1-2
VB2
OUT1-1
CB2-1
CB1-1
OUT2-1
VCC (O) 1
,
3
VB1
IN (C) 1
-
IN (E) 1
FB1
IN (C) 2
-
IN (E) 2
FB2
IN (C) 3
-
IN (E) 3
64
63
62
61
60
59
58
57
56
55
54
53
52
51
50
49
OUT1-5
VCC (O) 4
,
5
,
6
VB4
GND (O) 4
,
5
,
6
OUT2-4
CB1-4
CB2-4
OUT1-4
OUT1-3
CB2-3
CB1-3
GND (O) 1
,
2
,
3
VB3
VCC (O) 2
OUT1-2
CB2-2
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
FB5
IN (C) 4
-
IN (E) 4
FB4
RT
CT
CSCP
GND1
GND2
CS
VREF
VCC
CTL2
CTL1
DTC3
FB3
MB3825A
3
s
PIN DESCRIPTION
(Continued)
Pin No.
Symbol
I/O
Descriptions
CH 1
38
FB1
O
Channel 1 error amplifier output terminal.
39
-
IN (E) 1
I
Channel 1 error amplifier inverted input terminal.
40
IN (C) 1
I
Channel 1 short detection comparator input terminal.
46
OUT1-1
O
Channel 1 main side output terminal.
43
OUT2-1
O
Channel 1 synchronous rectifier side output terminal.
44
CB1-1
Channel 1 boot capacitor connection terminal.
45
CB2-1
41
VB1
Channel 1 output sink current setting terminal.
CH 2
35
FB2
O
Channel 2 error amplifier output terminal.
36
-
IN (E) 2
I
Channel 2 error amplifier inverted input terminal.
37
IN (C) 2
I
Channel 2 short detection comparator input terminal.
50
OUT1-2
O
Channel 2 output terminal.
48
CB1-2
Channel 2 boot capacitor connection terminal.
49
CB2-2
47
VB2
Channel 2 output sink current setting terminal.
CH 3
32
FB3
O
Channel 3 error amplifier output terminal.
33
-
IN (E) 3
I
Channel 3 error amplifier inverted input terminal.
34
IN (C) 3
I
Channel 3 short detection comparator input terminal.
56
OUT1-3
O
Channel 3 output terminal.
54
CB1-3
Channel 3 boot capacitor connection terminal.
55
CB2-3
52
VB3
Channel 3 output sink current setting terminal.
31
DTC3
I
Channel 3 dead time control terminal.
CH 4
20
FB4
O
Channel 4 error amplifier output terminal.
19
-
IN (E) 4
I
Channel 4 error amplifier inverted input terminal.
18
IN (C) 4
I
Channel 4 short detection comparator input terminal.
57
OUT1-4
O
Channel 4 main side output terminal.
60
OUT2-4
O
Channel 4 synchronous rectifier side output terminal.
59
CB1-4
Channel 4 boot capacitor connection terminal.
58
CB2-4
62
VB4
Channel 4 output sink current setting terminal.
MB3825A
4
(Continued)
Pin No.
Symbol
I/O
Descriptions
CH 5
17
FB5
O
Channel 5 error amplifier output terminal.
16
-
IN (E) 5
I
Channel 5 error amplifier inverted input terminal.
15
+
IN (E) 5
I
Channel 5 error amplifier non-inverted input terminal.
14
IN (C) 5
I
Channel 5 short detection comparator input terminal.
64
OUT1-5
O
Channel 5 output terminal.
2
CB1-5
Channel 5 boot capacitor connection terminal.
1
CB2-5
3
VB5
Channel 5 output sink current setting terminal.
8
OVP5, 6
I
Channel 5, 6 output maximum voltage setting terminal.
CH 6
12
FB6
O
Channel 6 error amplifier output terminal.
11
-
IN (E) 6
I
Channel 6 error amplifier inverted input terminal.
10
+
IN (E) 6
I
Channel 6 error amplifier non-inverted input terminal.
9
IN (C) 6
I
Channel 6 short detection comparator input terminal.
4
OUT1-6
O
Channel 6 output terminal.
6
CB1-6
Channel 6 boot capacitor connection terminal.
5
CB2-6
7
VB6
Channel 6 output sink current setting terminal.
8
OVP5, 6
I
Channel 5, 6 output maximum voltage setting terminal.
Triangular-
Wave
Oscillator
Circuit
21
RT
Triangular wave frequency setting resistor connection terminal.
22
CT
Triangular wave frequency setting capacitor connection terminal.
Control Circuit
30
CTL1
I
Power supply control circuit.
"H" level : Power supply operating mode
"L" level : Standby mode
29
CTL2
I
Channel 3 control circuit.
When CTL1 terminal is "H" level
"H" level : Channel 3 in operating mode
"L" level : Channel 3 in OFF mode
13
SCP
I
Short detection comparator input terminal.
23
CSCP
Short protection circuit capacitor connection terminal.
26
CS
Soft-start circuit capacitor connection terminal.
MB3825A
5
(Continued)
Pin No.
Symbol
I/O
Descriptions
Power Supply
Circuit
28
VCC
Reference voltage and control circuit power supply terminal.
42
VCC (O) 1, 3
Output circuit power supply terminal (Channel 1, 3) .
51
VCC (O) 2
Output circuit power supply terminal (Channel 2) .
63
VCC (O) 4, 5, 6
Output circuit power supply terminal (Channel 4, 5, 6) .
27
VREF
O
Reference voltage output terminal.
24
GND1
Ground terminal.
25
GND2
Ground terminal.
53
GND (O) 1, 2, 3
Output circuit ground terminal (Channel 1, 2, 3) .
61
GND (O) 4, 5, 6
Output circuit ground terminal (Channel 4, 5, 6) .
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