FUJITSU MB3825APFV

FUJITSU SEMICONDUCTOR
DATA SHEET
DS04-27220-2E
ASSP For Power Supply Applications
6-ch DC/DC Converter IC With Synchronous Rectifier
MB3825A
■ DESCRIPTION
The MB3825A is a pulse width modulation (PWM) type 6-channel DC/DC converter IC with synchronous rectification
(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.
■ 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.)
■ PACKAGE
64-pin, Plastic LQFP
(FPT-64P-M03)
MB3825A
2
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
64
63
62
61
60
59
58
57
56
55
54
53
52
51
50
49
■ PIN ASSIGNMENT
CB2-5
1
48
CB1-2
CB1-5
2
47
VB2
VB5
3
46
OUT1-1
OUT1-6
4
45
CB2-1
CB2-6
5
44
CB1-1
CB1-6
6
43
OUT2-1
VB6
7
42
VCC (O) 1, 3
OVP5, 6
8
41
VB1
IN (C) 6
9
40
IN (C) 1
+IN (E) 6
10
39
−IN (E) 1
−IN (E) 6
11
38
FB1
FB6
12
37
IN (C) 2
30
31
32
DTC3
FB3
27
VREF
CTL1
26
CS
29
25
GND2
28
24
GND1
VCC
23
CTL2
22
CT
CSCP
21
−IN (E) 3
20
IN (C) 3
33
RT
34
16
FB4
15
−IN (E) 5
19
+IN (E) 5
−IN (E) 4
FB2
18
−IN (E) 2
35
17
36
14
FB5
13
IN (C) 4
SCP
IN (C) 5
MB3825A
■ PIN DESCRIPTION
Pin No.
CH 1
CH 2
CH 3
CH 4
Symbol
I/O
Descriptions
38
FB1
O
Channel 1 error amplifier output pin.
39
–IN(E)1
I
Channel 1 error amplifier inverted input pin.
40
IN(C)1
I
Channel 1 short detection comparator input pin.
46
OUT1-1
O
Channel 1 main side output pin.
43
OUT2-1
O
Channel 1 synchronous rectifier side output pin.
44
CB1-1
—
45
CB2-1
—
41
VB1
—
Channel 1 output sink current setting pin.
35
FB2
O
Channel 2 error amplifier output pin.
36
–IN(E)2
I
Channel 2 error amplifier inverted input pin.
37
IN(C)2
I
Channel 2 short detection comparator input pin.
50
OUT1-2
O
Channel 2 output pin.
48
CB1-2
—
49
CB2-2
—
47
VB2
—
Channel 2 output sink current setting pin.
32
FB3
O
Channel 3 error amplifier output pin.
33
–IN(E)3
I
Channel 3 error amplifier inverted input pin.
34
IN(C)3
I
Channel 3 short detection comparator input pin.
56
OUT1-3
O
Channel 3 output pin.
54
CB1-3
—
55
CB2-3
—
52
VB3
—
31
DTC3
I
Channel 3 dead time control pin.
20
FB4
O
Channel 4 error amplifier output pin.
19
–IN(E)4
I
Channel 4 error amplifier inverted input pin.
18
IN(C)4
I
Channel 4 short detection comparator input pin.
57
OUT1-4
O
Channel 4 main side output pin.
60
OUT2-4
O
Channel 4 synchronous rectifier side output pin.
59
CB1-4
—
58
CB2-4
—
62
VB4
—
Channel 1 boot capacitor connection pin.
Channel 2 boot capacitor connection pin.
Channel 3 boot capacitor connection pin.
Channel 3 output sink current setting pin.
Channel 4 boot capacitor connection pin.
Channel 4 output sink current setting pin.
(Continued)
3
MB3825A
(Continued)
Pin No.
CH 5
Control
Circuit
Triangular-Wave
Oscillator Circuit
CH 6
Symbol
I/O
Descriptions
17
FB5
O
Channel 5 error amplifier output pin.
16
–IN(E)5
I
Channel 5 error amplifier inverted input pin.
15
+IN(E)5
I
Channel 5 error amplifier non-inverted input pin.
14
IN(C)5
I
Channel 5 short detection comparator input pin.
64
OUT1-5
O
Channel 5 output pin.
2
CB1-5
—
1
CB2-5
—
3
VB5
—
8
OVP5,6
I
Channel 5, 6 output maximum voltage setting pin.
12
FB6
O
Channel 6 error amplifier output pin.
11
–IN(E)6
I
Channel 6 error amplifier inverted input pin.
10
+IN(E)6
I
Channel 6 error amplifier non-inverted input pin.
9
IN(C)6
I
Channel 6 short detection comparator input pin.
4
OUT1-6
O
Channel 6 output pin.
6
CB1-6
—
5
CB2-6
—
7
VB6
—
8
OVP5,6
I
21
RT
—
Triangular wave frequency setting resistor connection pin.
22
CT
—
Triangular wave frequency setting capacitor connection pin.
30
CTL1
I
Power supply control circuit.
“H” level: Power supply operating mode
“L” level: Standby mode
Channel 5 boot capacitor connection pin.
Channel 5 output sink current setting pin.
Channel 6 boot capacitor connection pin.
Channel 6 output sink current setting pin.
Channel 5, 6 output maximum voltage setting pin.
29
CTL2
I
Channel 3 control circuit.
When CTL1 pin is “H” level
“H” level: Channel 3 in operating mode
“L” level: Channel 3 in OFF mode
13
SCP
I
Short detection comparator input pin.
23
CSCP
—
Short protection circuit capacitor connection pin.
26
CS
—
Soft start circuit capacitor connection pin.
(Continued)
4
MB3825A
(Continued)
Power Supply
Circuit
Pin No.
Symbol
I/O
Description
28
VCC
—
Reference voltage and control circuit power supply pin.
42
VCC(O)1,3
—
Output circuit power supply pin (Channel 1, 3).
51
VCC(O)2
—
Output circuit power supply pin (Channel 2).
63
VCC(O)4,5,6
—
Output circuit power supply pin (Channel 4,5,6).
27
VREF
O
Reference voltage output pin.
24
GND1
—
Ground pin.
25
GND2
—
Ground pin.
53
GND(O)1,2,3
—
Output circuit ground pin (Channel 1,2,3).
61
GND(O)4,5,6
—
Output circuit ground pin (Channel 4,5,6).
5
MB3825A
■ BLOCK DIAGRAM
• General view
VCC(O)1, 3
42
CB1-1
44
< CH1>
FB1
38
Error
Amp.1
−
+
+
39
−IN(E)1
PWM
Comp.1-1
+
45
CB2-1
Drive
1-1
−
1.5 V
46
OUT1-1
41
70 mV
−
40
IN(C)1
+
VB1
+
SCP
Comp.1
Drive
1-2
−
43
OUT2-1
PWM
Comp.1-2
1.5 V
A
VCC(O)2
51
CB1-2
48
<CH2>
FB2
35
Error
Amp.2
−
+
+
36
−IN(E)2
PWM
Comp.2
49
+
CB2-2
Drive
2
−
50
OUT1-2
1.5 V
47
VB2
SCP
Comp.2
−
37
IN(C)2
+
1.5 V
<CH3>
FB3
32
CB1-3
Error
Amp.3
−
33
−IN(E)3
54
PWM
Comp.3
55
+
+
−
+
Drive
3
CB2-3
56
OUT1-3
1.5 V
52
CTL2
VB3
29
IN(C)3
−
34
+
SCP
Comp.3
1.5 V
DTC3
GND(O)1, 2, 3
53
31
VCC(O)4, 5, 6
<CH4>
CB1-4
Error
Amp.4
−
+
+
19
−IN(E)4
59
PWM
Comp.4-1
58
+
Drive
4-1
−
1.5 V
SCP
Comp.4
−
18
+
CB2-4
57
OUT1-4
70 mV
IN(C)4
B
63
FB4
20
62
VB4
+
Drive
4-2
−
60
OUT2-4
PWM
Comp.4-2
1.5 V
<CH5>
FB5
17
Error
Amp.5
−
+
+
16
−IN(E)5
CB1-5
2
PWM
Comp.5
+
1
Drive
5
−
CB2-5
64
OUT1-5
3
14
−
15
+
VB5
SCP
Comp.5
0.6 V
IN(C)5
+IN(E)5
<CH6>
FB6
12
−
+
+
11
−IN(E)6
CB1-6
6
PWM
Comp.6
Error
Amp.6
5
+
Drive
6
−
CB2-6
4
OUT1-6
7
0.6 V
IN(C)6
+IN(E)6
9
−
10
+
VB6
SCP
Comp.6
GND(O)4, 5, 6
61
OVP5, 6
8
SCP
Comp.
−
13
SCP
VCC
Comp.
+
1.5 V
−
−
−
+
0.65 V
1 µA
CS
26
Buff
Soft Start
Comp.
1 µA
CSCP
23
−1.35V
−0.65V
−1.35V
−0.65V
−
+
1.5 V
SCP
UVLO
OSC
Ref
1.5 V
21 22
27
RT CT VREF
6
VCC
28
Power
ON/OFF
25
24
GND1 GND2
CTL1
30
C
MB3825A
• Enlarged view of A
< CH1>
FB1
38
39
−IN(E)1
−
+
+
Error
Amp.1
+
PWM
Comp.1-1
−
1.5 V
45
CB2-1
Drive
1-1
40
IN(C)1
−
+
46
OUT1-1
41
70 mV
SCP
Comp.1
VCC(O)1, 3
42
CB1-1
44
VB1
+
−
Drive
1-2
43
OUT2-1
PWM
Comp.1-2
1.5 V
<CH2>
FB2
35
36
−IN(E)2
−
+
+
Error
Amp.2
PWM
Comp.2
49
+
−
VCC(O)2
51
CB1-2
48
CB2-2
Drive
2
50
OUT1-2
1.5 V
47
IN(C)2
37
−
SCP
Comp.2
VB2
+
1.5 V
7
MB3825A
• Enlarged view of B
<CH3>
FB3
32
CB1-3
−
33
−IN(E)3
Error
Amp.3
+
+
−
+
54
PWM
Comp.3
55
Drive
3
CB2-3
56
OUT1-3
1.5 V
52
CTL2
VB3
29
IN(C)3
34
−
+
1.5 V
DTC3
SCP
Comp.3
GND(O)1, 2, 3
53
31
<CH4>
FB4
20
19
−IN(E)4
CB1-4
−
+
+
Error
Amp.4
59
PWM
Comp.4-1
58
+
−
1.5 V
Drive
4-1
70 mV
IN(C)4
18
−
SCP
Comp.4
+
1.5 V
8
VCC(O)4, 5, 6
63
OUT1-4
62
+
−
PWM
Comp.4-2
CB2-4
57
VB4
Drive
4-2
60
OUT2-4
MB3825A
• Enlarged view of C
<CH5>
FB5
17
Error
Amp.5
−
+
+
16
−IN(E)5
CB1-5
2
PWM
Comp.5
+
1
Drive
5
−
CB2-5
64
OUT1-5
3
14
−
15
+
VB5
SCP
Comp.5
0.6 V
IN(C)5
+IN(E)5
<CH6>
FB6
12
−
+
+
11
−IN(E)6
CB1-6
6
PWM
Comp.6
Error
Amp.6
5
+
Drive
6
−
CB2-6
4
OUT1-6
7
0.6 V
IN(C)6
+IN(E)6
9
−
10
+
VB6
SCP
Comp.6
GND(O)4, 5, 6
61
OVP5, 6
8
SCP
Comp.
−
13
SCP
VCC
Comp.
+
1.5 V
−
−
−
+
0.65 V
1 µA
CS
26
Buff
Soft Start
Comp.
1 µA
CSCP
23
−1.35V
−0.65V
−1.35V
−0.65V
−
+
1.5 V
SCP
VCC
28
UVLO
OSC
21
RT
Ref
1.5 V
22
27
CT
VREF
Power
ON/OFF
CTL1
30
25
24
GND1 GND2
9
MB3825A
■ ABSOLUTE MAXIMUM RAGINGS
Parameter
Power supply voltage
Symbol
Conditions
VCC
—
Rating
Unit
Min.
Max.
—
17
V
Output current
Io
OUT pin
—
50
mA
Output peak current
Io
OUT pin, Duty ≤ 5%
—
200
mA
Power dissipation
PD
Ta ≤ +25°C
—
800*
mW
Storage temperature
Tstg
−55
+125
°C
—
*: The packages are mounted on the epoxy board (10 cm × 10 cm).
WARNING: Semiconductor devices can be permanently damaged by application of stress (voltage, current,
temperature, etc.) in excess of absolute maximum ratings. Do not exceed these ratings.
■ RECOMMENDED OPERATING CONDITIONS
Parameter
Symbol
Conditions
Power supply voltage
VCC
Reference voltage output
current
Value
Unit
Min.
Typ.
Max.
—
2.5
6.0
12
V
IOR
—
–1
—
0
mA
Input voltage
VIN
-IN(E),IN(C),OVP pin
0
—
VCC – 0.9
V
Control input voltage
VCTL
CTL pin
0
—
12
V
Main side OUT pin
2
—
20
mA
Output current
IO
Output current setting
resistor
RB
—
2.7
5.6
30
kΩ
Oscillator frequency
fOSC
—
50
500
800
kHz
Timing capacitor
CT
—
50
100
1500
pF
Timing resistor
RT
—
20
39
82
kΩ
Soft-start capacitor
CS
—
—
0.1
1.0
µF
CSCP
—
—
0.1
1.0
µF
Ta
—
–30
+25
+85
°C
Short detection capacitor
Operating ambient
temperature
WARNING: The recommended operating conditions are required in order to ensure the normal operation of the
semiconductor device. All of the device’s electrical characteristics are warranted when the device is
operated within these ranges.
Always use semiconductor devices within their recommended operating condition ranges. Operation
outside these ranges may adversely affect reliability and could result in device failure.
No warranty is made with respect to uses, operating conditions, or combinations not represented on
the data sheet. Users considering application outside the listed conditions are advised to contact their
FUJITSU representatives beforehand.
10
MB3825A
■ ELECTRICAL CHARACTERISTICS
(VCC = VCC(O) = +6 V, Ta = +25°C)
Conditions
Reference voltage
VREF
27
—
Output voltage
temperature stability
∆VREF
/VREF
27
Input stability
Line
Load stability
Value
Unit
Typ.
Max.
1.485
1.500
1.515
V
Ta = –30°C to +85°C
—
0.5*
—
%
27
VCC = 2.5 V to 12 V
—
2
10
mV
Load
27
VREF = 0 mA to –1 mA
—
2
10
mV
Short-circuit output current
IOS
27
VREF = 2 V
–10
–6
–1
mA
Threshold voltage
VTH
46
VCC =
—
2.1
—
V
Hysteresis width
VH
46
—
—
0.1
—
V
Reset voltage
VRST
46
—
1.8
2.0
—
V
Input standby voltage
VSTB
26
—
—
50
100
mV
Charge current
ICS
26
—
–1.4
–1.0
–0.6
µA
Threshold voltage
VTH
23
—
0.65
0.70
0.75
V
Input standby voltage
VSTB
23
—
—
50
100
mV
VI
23
—
—
50
100
mV
Input source current
ICSCP
23
—
–1.4
–1.0
–0.6
µA
Oscillator frequency
fOSC
46,50,56, CT = 100 pF,
57,64,4 RT = 39 kΩ
450
500
550
kHz
Under voltage
lockout protection
circuit block(U.V.L.O)
Reference
voltage
block
Min.
Soft-start
block
Pin No.
Short circuit
detection block
Symbol
Triangular
wave oscillator
block
Parameter
Input latch voltage
Frequency stability for
voltage
∆f/fdv
46,50,56,
VCC = 2.5 V to 12 V
57,64,4
—
1
10
%
Frequency stability for
temperature
∆f/fdt
46,50,56,
Ta = –30°C to +85°C
57,64,4
—
1*
—
%
*: Standard design value.
(Continued)
11
MB3825A
(Continued)
(VCC = VCC(O) = +6 V, Ta = +25°C)
Error amplifier bolck
(CH5, CH6)
Error amplifier block
(CH1 to CH4)
Parameter
Conditions
Threshold voltage
VTH
38,35,
FB = 1.0 V
32,20
VT temperature stability
∆VT
/VT
38,35,
Ta = –30°C to +85°C
32,20
Value
Unit
Min.
Typ.
Max.
1.45
1.50
1.55
V
—
0.5*
—
%
–200
–20
—
nA
Input bias current
IB
39,36,
−IN = 0 V
33,19
Voltage gain
AV
38,35,
DC
32,20
60
75
—
dB
Frequency bandwidth
BW
38,35,
AV = 0 dB
32,20
—
1.0*
—
MHz
VOM+
38,35,
32,20
—
1.45
1.55
—
V
VOM−
38,35,
32,20
—
—
20
200
mV
—
–2.0
–0.6
mA
Maximum output voltage
width
Output source current
IO−
38,35,
FB = 1.0 V
32,20
Output sink current
IO+
38,35, FB = 1.0 V (CH1,CH4)
32,20 FB = 1.0 V (CH2,CH3)
60
120
—
µA
60
130
—
µA
Input offset voltage
VIO
17,12
FB = 1.0 V
–1
9
19
mV
VT temperature stability
∆VT
/VT
17,12
Ta = –30°C to +85°C
—
0.5*
—
%
15,10
+IN = 0 V, +IN(E) pin
–400
–40
—
nA
16,11
−IN = 0 V, −IN(E) pin
–200
–20
—
nA
8
OVP = 0 V, OVP pin
–400
–40
—
nA
0
—
VCC–0.9
V
Input bias current
IB
Common mode input
voltage range
VCM
17,12
Voltage gain
AV
17,12
DC
60
75
—
dB
Frequency bandwidth
BW
17,12
AV = 0 dB
—
1.0*
—
MHz
+
OM
17,12
—
1.45
1.55
—
V
VOM−
17,12
—
—
20
200
mV
Maximum output voltage
width
V
—
IO
−
17,12
FB = 1.0 V
—
–2.0
–0.6
mA
Output sink current
IO
+
17,12
FB = 1.0 V
60
130
—
µA
Threshold voltage
VTH
1.45
1.50
1.55
V
Input bias current
IB
–200
–20
—
nA
Output source current
SCP Comp. block
(CH1 to CH4,
SCP)
Symbol Pin No
46,50,
56,57
—
40,37,
IN(C) = SCP = 0 V
34,18,13
*: Standard design value.
(Continued)
12
MB3825A
(Continued)
(VCC = VCC(O) = +6 V, Ta = +25°C)
VCC
Comp.
block
Control
block
Synchronous
rectifier side output block
(CH1, CH4) (Drive-2)
Main side output
block (CH1 to CH6)
(Drive-1)
Dead time control
block
(CH3) (DTC pin)
PWM Comp.
block
(CH1 to CH6)
SCP Comp.
block
(CH5, CH6)
Parameter
Symbol Pin No.
Input offset voltage
VIO
64,4
Input bias current
IIN+
14,9
Common mode input
voltage range
VCM
64,4
VT0
Threshold voltage
VT100
Conditions
—
IN(C) = 0 V
—
46,50,
56,57, Duty cycle = 0 %
64,4
46,50,
56,57, Duty cycle = 100 %
64,4
Value
Unit
Min.
Typ.
Max.
0.55
0.60
0.65
V
–400
–40
—
nA
0
—
VCC–0.9
V
0.55
0.65
—
V
—
1.35
1.45
V
IB
31
DTC = 0.4 V
–1.0
–0.2
—
µA
Sink current at CTL2 = “L”
IIDTC
31
DTC = 1.5 V
CTL2 = 0 V
80
500
—
µA
Input voltage
at CTL2 = “L”
VIDTC
31
IDTC = 40 µA
CTL2 = 0 V
—
0.2
0.3
V
Input bias current
Output source current
IO−
46,50,
56,57, Duty cycle ≤ 5 %
64,4
—
–100
—
mA
Output sink current
IO+
46,50,
56,57, RB = 5.6 kΩ
64,4
7
10
13
mA
Output source current
IO−
43,60
Duty cycle ≤ 5 %,
VO = 2 V
—
–70
—
mA
Output sink current
IO+
43,60
Duty cycle ≤ 5 %,
VO = 1 V
—
70
—
mA
VOH
43,60
—
3.5
4.0
—
V
VOL
43,60
—
—
0
0.1
V
VON
27
IC active mode
2.1
—
12
V
VOFF
27
IC standby mode
0
—
0.7
V
Input current
ICTL
30
CTL = 5 V
—
100
200
µA
Threshold voltage
VTH
46,50,
56
VCC –
0.70
VCC –
0.65
VCC –
0.60
V
Output voltage
CTL input condition
—
*: Standard design value.
(Continued)
13
MB3825A
(Continued)
(VCC = VCC(O) = +6 V, Ta = +25°C)
Parameter
Symbol Pin No.
General
ICCS
Standby current
ICCS(O)
Power supply current
*: Standard design value.
14
ICC
Conditions
Value
Unit
Min.
Typ.
Max.
—
—
10
µA
42,51, VCC(O) pin, CTL = 0V
63
—
—
10
µA
28,42,
51,63
—
6.3
9.0
mA
28
VCC pin, CTL = 0V
—
MB3825A
■ TYPICAL CHARACTERISTICS
Reference voltage vs. power supply voltage
2.5
10.0
Ta = +25 °C
VCTL1, 2 = 6 V
Reference voltage VREF (V)
Power supply current ICC (mA)
Power supply current vs. power supply voltage
8.0
6.0
4.0
2.0
5
10
15
1.5
1.0
0.5
20
0
Power supply voltage VCC (V)
5
10
15
20
Power supply voltage VCC (V)
Reference voltage vs. ambient temperature
Reference voltage vs. power supply voltage
1.55
Ta = +25 °C
VCC = 6 V
1.54 VCTL1, 2 = 6 V
IO = 0 mA
1.53
Reference voltage VREF (V)
Reference voltage VREF (V)
2.0
0.0
0.0
0
2.5
Ta = +25 °C
2.0
1.5
1.0
0.5
1.52
1.51
1.50
1.49
1.48
1.47
1.46
0.0
0
1
2
3
4
5
1.45
−50
Power supply voltage VCC (V)
500
Ta = +25 °C
VCC = 6 V
Control current ICTL1 (µA)
Reference voltage VREF (V)
2.0
1.5
1.0
0.5
0
1
2
3
Control voltage VCTL1 (V)
4
0
25
50
75
100
Ambient temperature Ta (°C)
Control current vs. control voltage
Reference voltage vs. control voltage
0.0
−25
5
Ta = +25 °C
VCC = 6 V
400
300
200
100
0
0
5
10
15
20
Control voltage VCTL1 (V)
(Continued)
15
MB3825A
(Continued)
Triangular wave upper and lower limit voltage
vs. timing capacitor
Control current vs. control voltage
Ta = +25 °C
VCC = 6 V
VCTL1 = 6 V
400
300
200
100
0
0
1.6
Triangular wave upper and lower
limit voltage VCT (V)
Control current ICTL2 (µA)
500
5
10
15
Ta = +25 °C
VCC = 6.0 V
RT = 39 kΩ
1.2
1.0
10
1
0
10
102
103
104
Timing capacitor CT (pF)
10 k
1k
1k
−5
−10
−15
−50
−25
0
25
50
75
Ambient temperature Ta (°C)
100
10 k
100 k
1M
Timing resistor RT (Ω)
Triangular wave upper and lower limit voltage
vs. ambient temperature
1.6
0
CT = 1500 pF
100 k
1.7
5
104
Ta = +25 °C
VCC = 6.0 V
CT = 47 pF
CT = 100 pF
CT = 150 pF
CT = 300 pF
1M
15
VCC = 6.0 V
CT = 100 pF
10 RT = 39 kΩ
103
10 M
Triangular wave upper and
lower limit voltage VCT (V)
Triangular wave frequency stability (%)
Triangular wave frequency stability
vs. ambient temperature
102
Timing capacitor CT (pF)
Oscillator frequency vs. timing resistor
CT1,CT2 oscillator frequency fOSC (Hz)
Triangular wave time (µs)
Ta = +25 °C
VCC = 6 V
RT = 39 kΩ
Lower
0.8
10
20
Control voltage VCTL2 (V)
Triangular wave time vs. timing capacitor
100
Upper
1.4
1.5
VCC = 6.0 V
RT = 39 kΩ
CT = 100 pF
upper
1.4
1.3
1.2
1.1
1.0
0.9
lower
0.8
0.7
−50
−25
0
25
50
75
100
Ambient temperature Ta (°C)
(Continued)
16
MB3825A
(Continued)
Duty vs. oscillator frequency (ch1)
Duty vs. oscillator frequency (ch4)
100
100
70
70
Ta = +25 °C
90 VCC = 6.0 V
VFB = 1.0 V
80
Duty Dtr (%)
Duty Dtr (%)
Ta = +25 °C
90 VCC = 6.0 V
VFB = 1.0 V
80
60
50
40
30
60
50
40
30
20
20
10
10
0
1k
10 k
100 k
1M
10 M
Oscillator frequency fOSC (Hz)
0
1k
10 k
100 k
1M
10 M
Oscillator frequency fOSC (Hz)
Output sink current vs.
output sink current setting resistor
Output sink current IO (mA)
20
Ta = +25 °C
VCC = 6.0 V
18
16
14
12
10
8
6
4
2
0
0
5
10
15
20
25
30
Output sink current setting resistor RB (kΩ)
(Continued)
17
MB3825A
(Continued)
Error amplifier gain and phase vs. frequency (ch1)
Ta = +25 °C
180
VCC = 6 V
20
90
φ
AV
0
0
−20
−90
−40
−180
1k
10 k
100 k
1M
4.7 kΩ
Phase φ (deg)
Gain AV (dB)
40
240 kΩ
− + 2.4 kΩ
IN
10 µF
VREF
CS
4.7 kΩ
39
26
−
+
+
38
OUT
10 M
Frequency f (Hz)
Error amplifier gain and phase vs. frequency (ch5)
Ta = +25 °C
40
180
90
φ
AV
0
0
−20
−90
−40
−180
1k
10 k
100 k
1M
Phase φ (deg)
Gain AV (dB)
3V
20
4.7 kΩ
IN − +
4.7 kΩ
2.4 kΩ
10 µF
4.7 kΩ
4.7 kΩ
1M
Frequency f (Hz)
Power dissipation vs. ambient temperature
Power dissipation PD (mW)
1000
800
600
400
200
0
−50
−25
0
25
50
75
Ambient temperature Ta (°C)
18
100
VCC = 6 V
240 kΩ
16 −
15 +
8 +
6V
17
OUT
MB3825A
■ FUNCTIONAL DESCRIPTION
1. Switching Regulator Function
(1) Reference voltage circuit
The reference voltage circuit generates a temperature-compensated reference voltage (=: 1.500 V) using the voltage
supplied from the power supply terminal (pin 28). This voltage is used as the reference voltage for the internal
circuits of the IC. The reference voltage of up to 1mA can also be supplied to an external device from the VREF
terminal (pin 27).
(2) Triangular-wave oscillator circuit
By connecting a timing capacitor and a resistor to the CT (pin 22) and the RT (pin 21) terminals, it is possible to
generate any desired triangular oscillator waveform (CT : amplitude 1.0V to 1.4V, CT1 : amplitude 0.65V to 1.35V
in phase with CT1, and CT2 : amplitude 0.65V to 1.35V in inverse phase with CT). The triangular wave is input to
CT1, CT2 and the PWM comparator within the IC.
(3) Error amplifier
This amplifier detects the output voltage of the switching regulator and outputs a PWM control signal accordingly.
It has a wide common-mode input voltage range from 0 V to VCC –0.9 V on channels 5 and 6 allows easy setting
from an external power supply, making the system suitable for DC motor speed control.
By connecting a feedback resistor and capacitor from the error amplifier output pin to the inverted input pin, you
can form any desired loop gain, for stable phase compensation.
(4)
PWM comparator
The PWM comparators in these channels are a voltage comparator with one inverted input and one non-inverted
input (channels 1, 2, 4, 5, 6) as well as one inverted input and two non-inverted inputs (channel 3), and voltage
pulse width modifier to control output duty according to input voltage.
In the interval when the error amplifier output voltage is higher than the triangular waveform, the output transistor
is turned on (channels 1, 2, 4, 5, 6).
In the interval when the error amplifier output voltage is lower than the triangular waveform, the output transistor
is turned on (channel 1,4 synchronous rectifier side).
In the interval when the error amplifier output voltage and DTC3 voltage are higher than the triangular waveform,
the output transistor is switched on (channel 3).
(5) Output circuit
The output circuits is comprised of a totem-pole configuration on both the main side and synchronous rectifier side,
and can drive an external PNP transistor (main side) or N-ch MOSFET (synchronous rectifier side).
Sink current (on the main side) can be set up to 20 mA depending on the resistance of the VB pin.
2. Channel Control Function
Channel on and off levels are dependent on the voltage levels of the CTL1 terminal (pin 30) and CTL 2 terminal
(pin 29).
Table 1 Channel by Channel On/Off Setting Conditions.
CTL pin voltage
level
CTL1
CTL2
L
X
H
L
H
On/Off state of channel
Power
supply
circuit
Channel 1 Channel 2 Channel 4 Channel 5
Channel 6
Channel 3
OFF (standby mode)*
ON
OFF
ON
*: The power supply current in standby mode is 10 µA or less.
19
MB3825A
3. Protective Functions
(1) Timer-latch short-circuit protection circuit
The short detection comparator in each channel detects the output voltage level, and when any channel output
voltage falls below the short detection voltage, or the SCP terminal (pin 13) voltage falls below the reference voltage,
the timer circuit starts operating and the capacitor CSCP connected to the CSCP terminal (pin 23) starts charging.
When the capacitor charge reaches approximately 0.7 V, the output transistor is turned off and the idle interval
becomes 100%.
When actuated, this protection circuit can be reset by turning on the power supply again.(See “METHOD OF
SETTING TIME CONSTANT FOR TIMER-LATCH SHORT PROTECTION CIRCUIT”.)
(2) Under voltage lockout protection circuit
A transient state at power-on or a momentary drop of the power supply voltage causes the control IC to malfunction,
resulting in system breakdown or system deterioration. By detecting the internal reference voltage with respect to
the power supply voltage, this protection circuit resets the latch circuit to turn off the output transistor and set the
duty (OFF) = 100 %, while at the same time holding the CSCP terminal (pin 23) at the “L”. The reset is cleared
when the power supply voltage becomes greater than or equal to the threshold voltage level of this protection circuit.
(3) Output Supply Monitor Comparator (Vcc Comp.)
The output supply monitor comparator compares the output circuit power supply (VCC(O)1, 3,VCC(O)2, VCC(O)
4, 5, 6) to the VCC level, and operates the timer-latch short protection circuit if any of the output circuit power
supplies fall below Vcc –0.65V.
20
MB3825A
■ METHODS OF SETTING THE OUTPUT VOLTAGE
Figure 1. CH1 to CH4
VO
VO =
R1
VO >
R2
−
+
+
39
R3
−IN (E) 1
1.5 V
(R1 + R2 + R3)
R3
1.5 V
R2 + R3
(R1 + R2 + R3)
Error
Amp.1
1.5 V
−
40
IN (C) 1
SCP
Comp.1
+
1.5 V
Figure 2. CH5 and CH6
VO
FB5
VO =
17
R1
−
+
+
16
R2
−IN (E)5
Error
Amp.5
V+IN (E) 5
(R1 + R2)
R2
VOVP5, 6 > V+IN (E) 5
VO =
VOVP5, 6
(R1 + R2)
R2
VOVP5, 6 < V+IN (E) 5
IN (C) 5
Motor
control
signal
0.6 V
14
−
15
+
SCP
Comp.5
+IN (E) 5
8
OVP5, 6
21
MB3825A
■ METHOD OF SETTING THE OUTPUT CURRENT
Figure 3 shows the configuration of the output circuits, and Figure 4 illustrates how the sink current value of the
output current waveform has a constant current setting. Note that the sink current is set by the following formula
• Sink current = (VB/RB) × 60 =: 56/RB [A]
Figure 3. Output circuit (main side)
External PNP transistor
VB
RB
VB
VCC(O)
Output ON
base current
speed-up
100 kΩ
Source
current
CB1
OUT1
10 kΩ
To PWM
comparator
Output OFF
driver
CB2
Sink current
× 60
×1
GND (O)
Figure 4. Output current waveform
Speed-up current
Sink current
Output current 0
Source current (peak)
t
22
MB3825A
Precautions:
Output current setting resistance RB1 to RB6 should be connected to each channel as shown in Figure 5 below.
• For channel 1 and 3, connect the respective VB terminals to VCC(O) 1, 3 through the setting resistor RB.
• For channel 2, connect the VB2 terminal to VCC(O)2 through setting resistor RB2.
• For channels 4 to 6, connect the respective VB terminals to VCC(O)4, 5, 6 through setting resistor RB.
Figure 5. Output sink current setting pin connections
VCC(O) 1, 3
VB1
RB1
VB3
RB3
VCC(O) 2
MB3825A
VB2
RB2
VCC(O) 4, 5, 6
VB4
RB4
VB5
RB5
VB6
RB6
23
MB3825A
■ METHOD OF SETTING TIME CONSTANT FOR TIMER-LATCH SHORT PROTECTION
CIRCUIT
The short detection comparator (SCP comparator) in each of the channels constantly compares the error amplifier
output level to the reference voltage and the SCP terminal (pin 13).
While the switching regulator load conditions are stable on all channels, or when the voltage level at the SCP terminal
is higher than the reference voltage, the short detection comparator output remains at “L” level, transistor Q3 is
turned on, and the CSCP terminal (pin 23) is held at input standby voltage (VSTB =: 50mV).
If the load conditions change rapidly due to a short-circuiting of load, causing the output voltage to drop, or if the
voltage at the SCP terminal falls below the reference voltage level, the output from the short detection comparator
on the corresponding channel or the input at the SCP pin goes to “H” level. This causes transistor Q3 to turn off
and the external short protection capacitor CSCP connected to the CSCP terminal to charge at 1.0 µA.
Short Detection Time (tPE)
tPE(sec) =: 0.7 × CSCP (µF)
When the capacitor CSCP is charged to the threshold voltage VTH =: 0.7 V the SR latch is set, and the external PNP
is turned off (inactive interval is set to 100%). At this point the SR latch input is closed and the CSCP pin is held at
input latch voltage (VI =: 50 mV).
External PNP transistor
Figure 6. Protection timer-latch short protection circuit
A
R1
−
40
R2
SCP
Comp.1
IN (C) 1
Output
stage
46
Output
stage
43
OUT1-1
+
1.5 V
R3
−
13
SCP
SCP
Comp.
OUT2-1
+
Output
stage
1.5 V
1 µA
56
OUT1-3
CS
Buff
26
Q2
Soft Start
Comp.
Output
stage
−
+
1 µA
CSCP
24
bias
bias
S
CSCP
Q1
29
CTL2
1.5 V
23
Q3
R
Timer-latch
short circuit
protection
circuit
4
OUT1-6
28
VCC
UVLO
Ref
Power
ON/OFF
30
CTL1
27
VREF
MB3825A
■ TREATMENT WITHOUT USING CSCP
When you do not use the timer-latch short protection circuit, connect the CSCP terminal (pin 23) to GND with the
shortest distance.
Figure 7. Treatment when not using CSCP
23 CSCP
24 GND1
25 GND2
25
MB3825A
■ METHOD OF SETTING SOFT START TIME
• Channels 1, 2, 4
To provide a soft start by preventing current surges at power-on, soft start capacitor (Cs) can be connected to the
CS terminal (pin 26).
When the IC is started (when the CTL1 terminal (pin 30) goes to “H” level, and Vcc ≥ UVLO threshold voltage),
transistors Q2 switches off and the CS terminal begins charging the external soft start capacitors (Cs) at 1.0 µA.
The error amplifier makes a soft start in a proportion to the output voltage to the CS teminal voltage regardless of
the load current on the DC/DC converter.
Note that the soft start time can be calculated by the following formula.
Soft start time (output rise time)
tS(sec) =: 1.5 × CS (µF)
Figure 8. Soft start circuit
External PNP transistor
A
FB1
38
R1
−
+
+
39
−IN (E )1
R2
Error
Amp.1
Output
stage
46
Output
stage
43
1.5 V
R3
Output
stage
1 µA
OUT1-1
OUT2-1
56
OUT1-3
CS
26
CS
Buff
Q2
Soft Start
Comp.
−
Output
stage
+
1 µA
CSCP
29
1.5 V
SCP
Q1
CTL2
28
VCC
bias
23
CSCP
4
OUT1-6
UVLO
Ref
Power
ON/OFF
30
CTL1
27
VREF
26
MB3825A
• Channel 3
The capacitor CDTC3 is placed between the DTC3 terminal (pin 31) and GND, so that when the CTL2 terminal (pin
29) goes from “L” to “H” level, the transistor Q4 is turned off and the output voltage is in proportion to the DTC3
terminal voltage providing the soft start operation.
As the short detection function is not turned off during soft start operation, this setting should be made under the
following condition.
Channel 3 soft start circuit time < Short detection time
Figure 9. Channel 3 soft start circuit
A
External PNP transistor
FB3
32
−
33
−IN (E) 3
Error
Amp.3
+
+
−
+
PWM
Comp.3
Output
stage
OUT1-3
1.5 V
H:ON (CH3) CTL2
L:OFF
29
34
56
Q4
−
IN (C) 3
+
To VREF
1.5 V
Ra
SCP
Comp.3
DTC3
34
Rb
CDTC3
To CT1 To CSP
To UVLO
27
MB3825A
■ PROCESSING WITHOUT USING CS PIN
If the soft start function is not used, the CS terminal (pin 26) for channels 1, 2, and 4 should be left open.
For channel 3, connect the DTC3 terminal (pin 31) to the VREF terminal (pin 27).
Figure 10. When no soft start time is set (1,2,4 channel)
Open
26 CS
Figure 11. When no soft start time is set (3 channel)
27 VREF
31 DTC3
28
MB3825A
■ METHOD OF SETTING THE DEAD TIME
When the device is set for step-up inverted output based on the flyback method, the output transistor is fixed to
full-on state (ON-duty = 100 %) at power switch-on.To prevent this problem, you may determine the voltages on the
DTC3 terminal (pin 31) from the VREF voltage so you can easily set the output transistor’s dead time (maximum ONduty) independently for each channel as shown Figure.12.
When the voltage on the DTC3 terminal is lower than the triangular-wave (CT1) output voltage from the oscillator,
the output transistor turns off. The dead time calculation formula assuming that triangular-wave amplitude =: 0.7 V
and triangular-wave maximum voltage =: 1.35 V is given below.
Duty (ON) MAX =:
Vdt – 0.65
× 100 [%]
0.7
When you do not use this DTC3 terminal, connect then to VREF terminal (pin 27) as shown Figure.13..
Figure 12. When using DTC to set dead time
27 VREF
Ra
31 DTC3
Vdt
Rb
Figure 13. When not using DTC to set dead time
27 VREF
31 DTC3
29
MB3825A
■ APPLICATION EXAMPLE
• General view
VFB1
VOUT1-1
VCC(O)1, 3
42
CB1-1
44
560 pF
45
CB2-1
< CH1>
13.5 kΩ
3.5 kΩ
V C1
10 µH
4.7 µF
A
FB1
38
0.033 µF
PWM
Comp.1-1
Error
Amp.1
−
+
+
39
−IN(E)1
15 kΩ
+
Drive
1-1
−
1.5 V
46
OUT1-1
+
Drive
1-2
−
OUT2-1
VOUT2-1
10 µH
4.7 µF
B
12 kΩ
VCC(O)2
51
CB2-2
48
560 pF
49
CB1-2
<CH2>
0.033 µF
FB2
35
15 kΩ
Error
Amp.2
−
+
+
36
−IN(E)2
30Ω
43
PWM
Comp.1-2
1.5 V
23.5 kΩ
6.8 µF
U1FWJ44N
22 kΩ
VB1
+
SCP
Comp.1
−
2SK2316
VO1
VO1(3.2 V)
41
70 mV
40
IN(C)1
FMMT717
A
68 µH
PWM
Comp.2
−
Drive
2
+
FMMT717
B
VO2(5.05 V)
A
33 µH
6.8 µF
U1FWJ44N
50Ω
50
OUT1-2
1.5 V
22 kΩ
47
VB2
IN(C)2
SCP
Amp.2
−
37
+
1.5 V
C
C
<CH3>
42.5 kΩ
2.5 kΩ
0.033 µF
FB3
32
CB1-3
Error
Amp.3
−
33
−IN(E)3
5 kΩ
PWM
Comp.3
Drive
3
2.2 µF
CB2-3
750Ω
56
OUT1-3 22 kΩ
1.5 V
52
CTL2
H : ON(CH3) 29
L : OFF
34
IN(C)3
30 kΩ
VO3(15 V)
1SS196
560 pF
55
+
+
−
+
2SB1121
54
VB3
−
+
SCP
Comp.3
1.5 V
DTC3
GND(O)1, 2, 3
53
31
B
120 kΩ
10 µH
D
VCC(O)4, 5, 6
<CH4>
13.5 kΩ
7.5 kΩ
0.033 µF
9.3 kΩ
63
FB4
20
CB1-4
Error
Amp.4
−
+
+
19
−IN(E)4
IN(C)4
−
18
Drive
4-1
CB2-4
VO4(4.89 V)
33 µH
6.8 µF
57
2SK2316
OUT1-4 22 kΩ
70mV
+
D
560 pF
58
−
SCP
Comp.4
FMMT717
59
PWM
Comp.4-1
+
1.5 V
4.7 µF
U1FWJ44N
50Ω
62
+
VB4
Drive
4-2
−
60
OUT2-4
PWM
Comp.4-2
1.5 V
E
E
30 kΩ
0.033 µF
<CH5>
FB5
17
−
+
+
16
−IN(E)5
15 kΩ
Error
Amp.5
CB1-5
2
PWM
Comp.5
FMMT717
560 pF
1
+
Drive
5
−
VO5(4.5 V)
47 µH
2.2 µF
CB2-5
U1FWJ44N
100Ω
64
OUT1-5
22 kΩ
3
0.6 V
IN(C)5
14
−
15
+IN(E)5
+
VB5
SCP
Comp.5
VIN
(6V)
F
F
30 kΩ
0.033 µF
−
+
+
11
−IN(E)6
15 kΩ
VO6(4.5 V)
<CH6>
FB6
12
PWM
Comp.6
Error
Amp.6
FMMT717
CB1-6
6
560 pF
5
+
Drive
6
−
47 µH
2.2 µF
CB2-6
U1FWJ44N
100Ω
4
OUT1-6 22 kΩ
7
0.6 V
IN(C)6
+IN(E)6
9
−
10
+
C
VB6
SCP
Comp.6
GND(O)4, 5, 6
61
OVP5, 6
8
Over voltage
threshold
setting
voltage
−
13
SCP
SCP
Comp.
VCC
Comp.
+
1.5 V
FMMT717 : ZETEX plc.
−
−
−
+
2SB1121 : SANYO Electric Co., Ltd.
0.65 V
1 µA
2SK2316 : SANYO Electric Co., Ltd.
CS
26
0.1 µF
Buff
Soft Start
Comp.
1 µA
CSCP
0.1 µF
23
1.5 V
SCP
10 µH
VCC
4.7 µF
U1FWJ44N : TOSHIBA CORPORATION
28
UVLO
OSC
Ref
Power
ON/OFF
1.5 V
21
RT
39 k
22
CT
25
27 24
VREF GND1 GND2
100 pF
VCT
30
1SS196 : TOSHIBA CORPORATION
−1.35V
−0.65V
−1.35V
−0.65V
−
+
CTL1
30
H : ON (CH1,2,4 to 6)
L : OFF (standby state)
15 kΩ
12 kΩ
23.5 kΩ
B
15 kΩ
3.5 kΩ
38
IN(C)2
37
36
−IN(E)2
0.033 µF
FB2
35
40
IN(C)1
39
−IN(E)1
0.033 µF
FB1
Over voltage
threshold
setting
voltage
13.5 kΩ
A
VFB1
SCP
Comp.1
SCP
Amp.2
1.5 V
+
−
1.5 V
−
+
+
Error
Amp.2
1.5 V
+
−
1.5 V
−
+
+
Error
Amp.1
−
+
+
−
PWM
Comp.2
PWM
Comp.1-2
70 mV
−
+
PWM
Comp.1-1
Drive
2
<CH2>
Drive
1-2
Drive
1-1
< CH1>
OUT2-1
VB1
OUT1-1
22 kΩ
VB2
OUT1-2
22 kΩ
L : OFF (standby state)
H : ON (CH1,2,4 to 6)
47
50
VCC(O)2
51
CB2-2
48
560 pF
49
CB1-2
43
41
46
VCC(O)1, 3
42
CB1-1
44
560 pF
45
CB2-1
FMMT717
10 µH
4.7 µF
VOUT2-1
2SK2316
6.8 µF
33 µH
B
6.8 µF
U1FWJ44N
68 µH
A
U1FWJ44N
VC1
FMMT717
10 µH
4.7 µF
50Ω
VO2(5.05 V)
30Ω
VO1(3.2 V)
VO1
U1FWJ44N : TOSHIBA CORPORATION
1SS196 : TOSHIBA CORPORATION
2SK2316 : SANYO Electric Co., Ltd.
2SB1121 : SANYO Electric Co., Ltd.
FMMT717 : ZETEX plc.
VOUT1-1
MB3825A
• Enlarged view of A
31
32
C
9.3 kΩ
7.5 kΩ
13.5 kΩ
D
5 kΩ
2.5 kΩ
42.5 kΩ
FB3
32
31
FB4
20
DTC3
IN(C)4
18
19
−IN(E)4
0.033 µF
120 kΩ
30 kΩ
CTL2
H : ON(CH3) 29
L : OFF
34
IN(C)3
33
−IN(E)3
0.033 µF
Over voltage
threshold
setting
voltage
SCP
Comp.4
Error
Amp.4
SCP
Comp.3
1.5 V
+
−
1.5 V
−
+
+
1.5 V
+
−
1.5 V
+
−
Error
Amp.3
PWM
Comp.4-2
−
+
70mV
−
+
PWM
Comp.4-1
+
+
−
PWM
Comp.3
Drive
4-2
Drive
4-1
560 pF
VB3
OUT1-3 22 kΩ
CB2-3
CB1-3
60
62
57
58
59
63
53
560 pF
OUT2-4
VB4
OUT1-4 22 kΩ
CB2-4
CB1-4
VCC(O)4, 5, 6
GND(O)1, 2, 3
52
56
55
54
L : OFF (standby state)
H : ON (CH1,2,4 to 6)
<CH4>
Drive
3
<CH3>
2SK2316
FMMT717
4.7 µF
U1FWJ44N
6.8 µF
33 µH
D
2.2 µF
1SS196
50Ω
VO4(4.89 V)
750Ω
VO3(15 V)
U1FWJ44N : TOSHIBA CORPORATION
1SS196 : TOSHIBA CORPORATION
2SK2316 : SANYO Electric Co., Ltd.
2SB1121 : SANYO Electric Co., Ltd.
FMMT717 : ZETEX plc.
10 µH
2SB1121
C
MB3825A
• Enlarged view of B
VIN
(6V)
E
Over voltage
threshold
setting
voltage
15 kΩ
30 kΩ
F
15 kΩ
30 kΩ
0.1 µF
FB6
12
9
CSCP
CS
23
26
13
SCP
8
10
OVP5, 6
+IN(E)6
IN(C)6
11
−IN(E)6
0.033 µF
0.1 µF
14
15
+IN(E)5
IN(C)5
16
−IN(E)5
0.033 µF
FB5
17
SCP
1.5 V
+
−
SCP
Comp.
SCP
Comp.6
Error
Amp.6
SCP
Comp.5
1.5 V
+
−
+
−
−
+
+
+
−
Soft Start
Comp.
1 µA
Buff
1 µA
0.6 V
0.6 V
−
+
+
Error
Amp.5
RT
39 kΩ
UVLO
−
+
21
22
CT
OSC
PWM
Comp.6
−
+
PWM
Comp.5
Power
ON/OFF
0.65 V
100 pF
VCT
25
24
27
VREF GND1 GND2
Ref
1.5 V
−
−
−
+
−1.35V
−0.65V
−1.35V
−0.65V
VCC
Comp.
Drive
6
<CH6>
Drive
5
<CH5>
30
28
560 pF
22 kΩ
560 pF
CTL1
10 µH
U1FWJ44N
2.2 µF
47 µH
F
U1FWJ44N
2.2 µF
47 µH
4.7 µF
L : OFF (standby state)
H : ON (CH1,2,4 to 6)
FMMT717
FMMT717
100Ω
VO6(4.5 V)
100Ω
VO5(4.5 V)
U1FWJ44N : TOSHIBA CORPORATION
1SS196 : TOSHIBA CORPORATION
2SK2316 : SANYO Electric Co., Ltd.
2SB1121 : SANYO Electric Co., Ltd.
FMMT717 : ZETEX plc.
GND(O)4, 5, 6
VB6
OUT1-6 22 kΩ
CB2-6
CB1-6
VB5
OUT1-5
CB2-5
CB1-5
VCC
61
7
4
5
6
3
64
1
2
E
MB3825A
• Enlarged view of C
33
MB3825A
■ REFERENCE DATA
Channel 1 switching operation waveform (operation at 500 kHz)
Vin = 6 V
RL = 30 Ω
CT = 100 pF
RT = 39 kΩ
1V
VC1 (V)
6
4
2
0
500 nS
0
1
2
3
4
5
t (µs)
expansion
500 mV
VC1 (V)
3
2
1
0
200 nS
0
0.4
0.8
1.2
1.6
2.0
t (µs)
Synchronous rectifier length
34
=: 150 ns
=: 120 ns
MB3825A
Channel 1 main side output waveform (operation at 500 kHz)
500 mV
VC1 (V)
2V
Vin = 6 V
RL = 30 Ω
CT = 100 pF
RT = 39 kΩ
VC1
6
4
2
0
VCT
VCT (V)
VFB1 (V)
1.0
VFB1
0.5
500 nS
500 mV
0
0
1
2
3
4
5
t (µs)
Channel 1 main side base current waveform (operation at 500 kHz)
IOUT1-1 (mA)
60
500 mV
40
IOUT1-1
Vin = 6 V
RL = 30 Ω
CT = 100 pF
RT = 39 kΩ
20
0
−20
VCT
−40
VCT (V)
VFB1 (V) 1.0
−60
VFB1
0.5
500 mV
10 mV
−80
500 nS
−100
0
0
1
2
3
4
5
t (µs)
Peak current when turned ON =: 42 mA
Peak current when turned OFF =: 50 mA
(Continued)
35
MB3825A
(Continued)
Channel 1 synchronous rectifier side output waveform (operation at 500 kHz)
Vin = 6 V
RL = 30 Ω
CT = 100 pF
RT = 39 kΩ
2V
VC1 (V)
6
4
2
0
VOUT2-1 (V)
6
4
2
2V
500 nS
0
0
1
2
3
4
5
t (µs)
Channel 1 synchronous rectifier side output waveform (operation at 500 kHz)
IOUT2-1 (mA)
60
Vin = 6 V
RL = 30 Ω
CT = 100 pF
RT = 39 kΩ
10 mV
40
20
0
−20
−40
VOUT2-1 (V)
4
2
500 nS
2V
0
0
1
2
3
4
5
t (µs)
Output source current peak value =: 30 mA
Output sink current peak value =: 52 mA
36
MB3825A
■ USAGE PRECAUTIONS
1. Printed circuit board ground lines should be set up with consideration for common
impedance.
2. Take the following measures for protection against static charge:
• For containing semiconductor devices, use an antistatic or conductive container.
• When storing or transporting device-mounted circuit boards, use a conductive bag or container.
• Ground the workbenches, tools, and measuring equipment to earth.
• Make sure that operators wear wrist straps or other appropriate fittings grounded to earth via a resistance of
250 kΩ to 1 MΩ placed in series between the human body and earth.
■ ORDERING INFORMATION
Part number
MB3825APFV
Package
Remarks
64-pin plastic LQFP
(FPT-64P-M03)
37
MB3825A
■ PACKAGE DIMENSION
64-pin Plastic LQFP
(FPT-64P-M03)
12.00±0.20(.472±.008)SQ
10.00±0.10(.394±.004)SQ
48
33
49
32
0.08(.003)
Details of "A" part
INDEX
+0.20
1.50 –0.10
+.008
(Mounting height)
.059 –.004
64
17
"A"
LEAD No.
1
0.50±0.08
(.020±.003)
0~8°
16
0.18
.007
+0.08
–0.03
+.003
–.001
0.08(.003)
M
0.145±0.055
(.006±.002)
0.50±0.20
(.020±.008)
0.45/0.75
(.018/.030)
C
38
1998 FUJITSU LIMITED F64009S-3C-6
0.10±0.10
(.004±.004)
(Stand off)
0.25(.010)
Dimensions in: mm (inches)
MB3825A
FUJITSU LIMITED
For further information please contact:
Japan
FUJITSU LIMITED
Corporate Global Business Support Division
Electronic Devices
KAWASAKI PLANT, 4-1-1, Kamikodanaka
Nakahara-ku, Kawasaki-shi
Kanagawa 211-8588, Japan
Tel: 81(44) 754-3763
Fax: 81(44) 754-3329
http://www.fujitsu.co.jp/
North and South America
FUJITSU MICROELECTRONICS, INC.
Semiconductor Division
3545 North First Street
San Jose, CA 95134-1804, USA
Tel: (408) 922-9000
Fax: (408) 922-9179
Customer Response Center
Mon. - Fri.: 7 am - 5 pm (PST)
Tel: (800) 866-8608
Fax: (408) 922-9179
http://www.fujitsumicro.com/
Europe
FUJITSU MIKROELEKTRONIK GmbH
Am Siebenstein 6-10
D-63303 Dreieich-Buchschlag
Germany
Tel: (06103) 690-0
Fax: (06103) 690-122
http://www.fujitsu-ede.com/
Asia Pacific
FUJITSU MICROELECTRONICS ASIA PTE LTD
#05-08, 151 Lorong Chuan
New Tech Park
Singapore 556741
Tel: (65) 281-0770
Fax: (65) 281-0220
All Rights Reserved.
The contents of this document are subject to change without
notice. Customers are advised to consult with FUJITSU sales
representatives before ordering.
The information and circuit diagrams in this document are
presented as examples of semiconductor device applications,
and are not intended to be incorporated in devices for actual use.
Also, FUJITSU is unable to assume responsibility for
infringement of any patent rights or other rights of third parties
arising from the use of this information or circuit diagrams.
FUJITSU semiconductor devices are intended for use in
standard applications (computers, office automation and other
office equipment, industrial, communications, and measurement
equipment, personal or household devices, etc.).
CAUTION:
Customers considering the use of our products in special
applications where failure or abnormal operation may directly
affect human lives or cause physical injury or property damage,
or where extremely high levels of reliability are demanded (such
as aerospace systems, atomic energy controls, sea floor
repeaters, vehicle operating controls, medical devices for life
support, etc.) are requested to consult with FUJITSU sales
representatives before such use. The company will not be
responsible for damages arising from such use without prior
approval.
Any semiconductor devices have an inherent chance of
failure. You must protect against injury, damage or loss from
such failures by incorporating safety design measures into your
facility and equipment such as redundancy, fire protection, and
prevention of over-current levels and other abnormal operating
conditions.
If any products described in this document represent goods or
technologies subject to certain restrictions on export under the
Foreign Exchange and Foreign Trade Law of Japan, the prior
authorization by Japanese government will be required for
export of those products from Japan.
http://www.fmap.com.sg/
F9906
 FUJITSU LIMITED Printed in Japan
39