DS04-27220-5E
FUJITSU SEMICONDUCTOR
DATA SHEET
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 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 de vice 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.
■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 64-pin plastic LQFP
(FPT-64P-M03) (FPT-64P-M20)
MB3825A
2
■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
■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.
2CB1-5Channel 5 boot capacitor connection terminal.
1CB2-5
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.
6CB1-6Channel 6 boot capacitor connection terminal.
5CB2-6
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) .
MB3825A
6
■BLOCK DIAGRAM
•General view
38
39 45
44
40
FB1
1.5 V
−
+
+
−
+
+
+
−
+
−
−
+
+
−
−
+
Error
Amp.1
SCP
Comp.1
−IN(E)1
IN(C)1
FB2
−IN(E)2
1.5 V
70 mV
PWM
Comp.1-2
PWM
Comp.1-1
Drive
1-1
Drive
1-2
46
41
43
51
<CH1> 42
VCC(O)1, 3
CB1-1
CB2-1
OUT1-1
OUT2-1
VB1
36
37
35
1.5 V
1.5 V
SCP
Comp.2
<CH2>
<CH3>
<CH4>
<CH5>
<CH6>
Drive
2
Drive
3
Drive
4-1
Drive
4-2
50
47
48
49
54
55
56
52
53
VCC(O)2
CB1-2
CB2-2
OUT1-2
CB1-3
CB2-3
59
63
58
57
62
2
1
3
CB1-4
CB2-4
OUT1-4
VB4
OUT2-4
CB1-5
CB2-5
6
5
CB1-6
CB2-6
VB6
OUT1-6
VB5
OUT1-5
OUT1-3
VB3
VB2
Error
Amp.2 PWM
Comp.2
PWM
Comp.3
IN(C)2
−
+
−
+
−
+
−
+
+
−
+
−
+
−
FB3
CTL2
−IN(E)333
29
34
31
32
1.5 V
1.5 V
1.5 V
1.5 V
1.5 V
Error
Amp.3
Error
Amp.4
Error
Amp.5
SCP
Comp.5
SCP
Comp.4
IN(C)3
FB4
−IN(E)419
18
20
IN(C)4
FB5
−IN(E)5
16
15
14
17
IN(C)5
SCP
Comp.3
+
−
+
DTC3
−
+
+
−
+
+
70 mV
PWM
Comp.4-1
PWM
Comp.4-2
PWM
Comp.5
60
Drive
5
Drive
6
64
PWM
Comp.6
0.6 V
−
+
−
+
−
+
+
−
−
−
−
+
Error
Amp.6
SCP
Comp.6
SCP
Comp.
FB6
−IN(E)611
10
9
13
8
12
IN(C)6
−
+
+
0.6 V
+IN(E)5
+IN(E)6
OVP5, 6
4
7
61
30
25
24
27
22
VCC
Comp.
0.65 V
SCP
26
CS
CSCP
Buff
1 µA
1 µA
1.5 V
Soft Start
Comp.
23
SCP UVLO OSC Ref Power
ON/OFF
−1.35 V
−0.65 V
−1.35 V
−0.65 V VCC
CTL1
GND2GND1
1.5 V
VREF
21
RT CT
VCC(O)4, 5, 6
GND(O)1, 2, 3
GND(O)4, 5, 6
28
C
B
A
MB3825A
7
•Enlarged view of A
38
39 45
44
40
FB1
1.5 V
−
+
+
−
+
+
+
−
+
−
−
+
+
−
−
+
Error
Amp.1
SCP
Comp.1
−IN(E)1
IN(C)1
FB2
−IN(E)2
1.5 V
70 mV
PWM
Comp.1-2
PWM
Comp.1-1
Drive
1-1
Drive
1-2
46
41
43
51
<CH1> 42
VCC(O)1, 3
CB1-1
CB2-1
OUT1-1
OUT2-1
VB1
36
37
35
1.5 V
1.5 V
SCP
Comp.2
<CH2>
Drive
2 50
47
48
49
VCC(O)2
CB1-2
CB2-2
OUT1-2
VB2
Error
Amp.2 PWM
Comp.2
IN(C)2
MB3825A
8
•Enlarged view of B
<CH3>
<CH4>
Drive
3
Drive
4-1
Drive
4-2
54
55
56
52
53
CB1-3
CB2-3
59
63
58
57
62
CB1-4
CB2-4
OUT1-4
VB4
OUT2-4
OUT1-3
VB3
PWM
Comp.3
−
+
−
+
−
+
+
−
+
−
FB3
CTL2
−IN(E)333
29
34
31
32
1.5 V
1.5 V
1.5 V
1.5 V
Error
Amp.3
Error
Amp.4
SCP
Comp.4
IN(C)3
FB4
−IN(E)419
18
20
IN(C)4
SCP
Comp.3
+
−
+
DTC3
−
+
+
70 mV
PWM
Comp.4-1
PWM
Comp.4-2
60
VCC(O)4, 5, 6
GND(O)1, 2, 3
MB3825A
9
•Enlarged view of C
<CH5>
<CH6>
2
1
3
CB1-5
CB2-5
6
5
CB1-6
CB2-6
VB6
OUT1-6
VB5
OUT1-5
−
+
+
−
1.5 V
Error
Amp.5
SCP
Comp.5
FB5
−IN(E)5
16
15
14
17
IN(C)5
−
+
+
PWM
Comp.5
Drive
5
Drive
6
64
PWM
Comp.6
0.6 V
−
+
−
+
−
+
+
−
−
−
−
+
Error
Amp.6
SCP
Comp.6
SCP
Comp.
FB6
−IN(E)611
10
9
13
8
12
IN(C)6
−
+
+
0.6 V
+IN(E)5
+IN(E)6
OVP5, 6
4
7
61
30
25
24
27
22
VCC
Comp.
0.65 V
SCP
26
CS
CSCP
Buff
1 µA
1 µA
1.5 V
Soft Start
Comp.
23
SCP UVLO OSC Ref Power
ON/OFF
−1.35 V
−0.65 V
−1.35 V
−0.65 V VCC
CTL1
GND2GND1
1.5 V
VREF
21
RT CT
GND(O)4, 5, 6
28
MB3825A
10
■ABSOLUTE MAXIMUM RAGINGS
* : 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
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.
Parameter Symbol Conditions Rating Unit
Min Max
Power supply voltage VCC 17 V
Output current Io OUT terminal 50 mA
Output peak current Io OUT terminal, Duty ≤ 5% 200 mA
Power dissipation PDTa ≤ +25 °C800* mW
Storage temperature Tstg −55 +125 °C
Parameter Symbol Conditions Value Unit
Min Typ Max
Power supply voltage VCC 2.5 6.0 12 V
Reference voltage output
current IOR −10mA
Input voltage VIN −IN (E) , IN (C) ,
OVP terminal 0VCC − 0.9 V
Control input voltage VCTL CTL terminal 0 12 V
Output current IOMain side OUT terminal 2 20 mA
Output current setting
resistor RB2.7 5.6 30 kΩ
Oscillator frequency fOSC 50 500 800 kHz
Timing capacitor CT50 100 1500 pF
Timing resistor RT20 39 82 kΩ
Soft-start capacitor CS0.1 1.0 µF
Short detection capacitor CSCP 0.1 1.0 µF
Operating ambient
temperature Ta −30 +25 +85 °C
MB3825A
11
■ELECTRICAL CHARACTERISTICS (VCC = VCC (O) = +6 V, Ta = +25°C)
* : Standard design value.
(Continued)
Parameter Symbol Pin No. Conditions Value Unit
Min Typ Max
Reference
voltage
block
Reference voltage VREF 27 1.485 1.500 1.515 V
Output voltage
temperature stability ∆VREF
/VREF 27 Ta = −30 °C to +85 °C0.5* %
Input stability Line 27 VCC = 2.5 V to 12 V 210mV
Load stability Load 27 VREF = 0 mA to −1 mA 210mV
Short-circuit output
current IOS 27 VREF = 2 V −10 −6−1mA
Under
voltage
lockout
protection
circuit
block
(U.V.L.O)
Threshold voltage VTH 46 VCC = 2.1 V
Hysteresis width VH46 0.1 V
Reset voltage VRST 46 1.8 2.0 V
Soft-start
block Input standby voltage VSTB 26 50 100 mV
Charge current ICS 26 −1.4 −1.0 −0.6 µA
Short
circuit
detection
block
Threshold voltage VTH 23 0.65 0.70 0.75 V
Input standby voltage VSTB 23 50 100 mV
Input latch voltage VI23 50 100 mV
Input source current ICSCP 23 −1.4 −1.0 −0.6 µA
Triangular
wave
oscillator
block
Oscillator frequency fOSC 46, 50,
56, 57,
64, 4
CT = 100 pF,
RT = 39 kΩ450 500 550 kHz
Frequency stability for
voltage ∆f/fdv 46, 50,
56, 57,
64, 4 VCC = 2.5 V to 12 V 110%
Frequency stability for
temperature ∆f/fdt 46, 50,
56, 57,
64, 4 Ta = −30 °C to +85 °C1* %
MB3825A
12
(VCC = VCC (O) = +6 V, Ta = +25°C)
* : Standard design value.
(Continued)
Parameter Symbol Pin No Conditions Value Unit
Min Typ Max
Error
amplifier
block
(CH1 to
CH4)
Threshold voltage VTH 38, 35,
32, 20 FB = 1.0 V 1.45 1.50 1.55 V
VT temperature
stability ∆VT/VT38, 35,
32, 20 Ta = −30 °C to +85 °C0.5*%
Input bias current IB39, 36,
33, 19 −IN = 0 V −200 −20 nA
Voltage gain AV38, 35,
32, 20 DC 60 75 dB
Frequency bandwidth BW 38, 35,
32, 20 AV = 0 dB 1.0* MHz
Maximum output
voltage width
VOM+38, 35,
32, 20 1.45 1.55 V
VOM−38, 35,
32, 20 20 200 mV
Output source current IO−38, 35,
32, 20 FB = 1.0 V −2.0 −0.6 mA
Output sink current IO+38, 20 FB = 1.0 V (CH1, CH4) 60 120 µA
35, 32 FB = 1.0 V (CH2, CH3) 60 130 µA
Error
amplifier
bolck
(CH5,
CH6)
Input offset voltage VIO 17, 12 FB = 1.0 V −1919mV
Input bias current IB
15, 10 +IN = 0 V, +IN (E) terminal −400 −40 nA
16, 11 −IN = 0 V, −IN (E) terminal −200 −20 nA
8 OVP = 0 V, OVP terminal −400 −40 nA
Common mode input
voltage range VCM 17, 12 0VCC −
0.9 V
Voltage gain AV17, 12 DC 60 75 dB
Frequency bandwidth BW 17, 12 AV = 0 dB 1.0* MHz
Maximum output
voltage width VOM+17, 12 1.45 1.55 V
VOM−17, 12 20 200 mV
Output source current 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
SCP
Comp.
block
(CH1 to
CH4, SCP)
Threshold voltage VTH 46, 50,
56, 57 1.45 1.50 1.55 V
Input bias current IB40, 37,
34, 18, 13 IN (C) = SCP = 0 V −200 −20 nA
MB3825A
13
(VCC = VCC (O) = +6 V, Ta = +25°C)
* : Standard design value.
Parameter Symbol Pin No Conditions Value Unit
Min Typ Max
SCP
Comp.
block
(CH5,
CH6)
Input offset voltage VIO 64, 4 0.55 0.60 0.65 V
Input bias current IIN+14, 9 IN (C) = 0 V −400 −40 nA
Common mode input
voltage range VCM 64, 4 0VCC −
0.9 V
PWM
Comp.
block
(CH1 to
CH6)
Threshold voltage
VT0 46, 50,
56, 57,
64, 4 Duty cycle = 0%0.55 0.65 V
VT100 46, 50,
56, 57,
64, 4 Duty cycle = 100%1.35 1.45 V
Dead time
control
block
(CH3)
(DTC
terminal)
Input bias current IB31 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
Main side
output
block (CH1
to CH6)
(Drive-1)
Output source current IO−46, 50,
56, 57,
64, 4 Duty cycle ≤ 5%−100 mA
Output sink current IO+46, 50,
56, 57,
64, 4 RB = 5.6 kΩ71013mA
Synchro-
nous
rectifier
side output
block
(CH1,
CH4)
(Drive-2)
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
Output voltage VOH 43, 60 3.5 4.0 V
VOL 43, 60 00.1V
Control
block CTL input condition 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
VCC Comp.
block Threshold voltage VTH 46, 50,
56 VCC −
0.70 VCC −
0.65 VCC −
0.60 V
General Standby current ICCS 28 VCC terminal,
CTL = 0 V 10 µA
ICCS (O) 42, 51,
63 VCC (O) terminal,
CTL = 0 V 10 µA
Power supply current ICC 28, 42,
51, 63 6.3 9.0 mA
MB3825A
14
■TYPICAL CHARACTERISTICS
(Continued)
10.0
8.0
6.0
4.0
2.0
0.00 5 10 15 20
Ta = +25 °C
VCTL1, 2 = 6 V
2.5
2.0
1.5
1.0
0.5
0.00 5 10 15 20
Ta = +25 °C
2.5
2.0
1.5
1.0
0.5
0.0012345
Ta = +25 °C1.55
1.54
1.53
1.52
1.51
1.50
1.49
1.48
1.47
1.46
1.45
−50 −25 0 25 50 75 100
VCC = 6 V
VCTL1, 2 = 6 V
IO = 0 mA
2.0
1.5
1.0
0.5
0.0012345
Ta = +25 °C
VCC = 6 V
500
400
300
200
100
00 5 10 15 20
Ta = +25 °C
VCC = 6 V
Power supply current ICC (mA)
Power supply voltage VCC (V)
Power supply current vs. power supply voltage
Power supply voltage VCC (V)
Reference voltage vs. power supply voltage
Reference voltage VREF (V)
Power supply voltage VCC (V)
Reference voltage VREF (V)
Reference voltage vs. power supply voltage
Ambient temperature Ta (°C)
Reference voltage VREF (V)
Reference voltage vs. control voltage
Reference voltage VREF (V)
Control voltage VCTL1 (V) Control voltage VCTL1 (V)
Control current vs. control voltage
Control current ICTL1 (µA)
Reference voltage vs. ambient temperature
MB3825A
15
(Continued)
500
400
300
200
100
00 5 10 15 20
Ta = +25 °C
VCC = 6 V
VCTL1 = 6 V
1.6
1.4
1.2
1.0
0.8
10 102103104
Ta = +25 °C
VCC = 6.0 V
RT = 39 kΩ
100
10
1
0
10 102103104
Ta = +25 °C
VCC = 6 V
RT = 39 kΩ
10 M
1 M
100 k
10 k
1 k
1 k 10 k 100 k 1 M
Ta = +25 °C
VCC = 6.0 V
CT = 47 pF
CT = 100 pF
CT = 150 pF
CT = 300 pF
CT = 1500 pF
15
10
5
0
−5
−10
−15
−50 −25 0 25 50 75 100
VCC = 6.0 V
CT = 100 pF
RT = 39 kΩ
1.7
1.6
1.5
1.4
1.3
1.2
1.1
1.0
0.9
0.8
0.7
−50 −25 0 25 50 75 100
VCC = 6.0 V
RT = 39 kΩ
CT = 100 pF
Control current vs. control voltage
Control current ICTL2 (µA)
Control voltage VCTL2 (V)
Triangular wave upper and lower
limit voltage VCT (V)
Triangular wave upper and lower limit voltage
vs. timing capacitor
Timing capacitor CT (pF)
Triangular wave time vs. timing capacitor
Timing capacitor CT (pF)
Triangular wave time (µs)
Oscillator frequency vs. timing resistor
CT1, CT2 oscillator frequency fOSC (Hz)
Timing resistor RT (Ω)
Triangular wave frequency stability
vs. ambient temperature
Ambient temperature Ta ( °C)
Triangular wave frequency stability (%)
Ambient temperature Ta ( °C)
Triangular wave upper and lower limit voltage
vs. ambient temperature
Triangular wave upper and
lower limit voltage VCT (V)
Upper
Lower
lower
upper
MB3825A
16
(Continued)
100
90
80
70
60
50
40
30
20
10
0
1 k 10 k 100 k 1 M 10 M
Ta = +25 °C
VCC = 6.0 V
VFB = 1.0 V
100
90
80
70
60
50
40
30
20
10
0
1 k 10 k 100 k 1 M 10 M
Ta = +25 °C
VCC = 6.0 V
VFB = 1.0 V
20
18
16
14
12
10
8
6
4
2
00 5 10 15 20 25 30
Ta = +25 °C
VCC = 6.0 V
Duty vs. oscillator frequency (ch1)
Duty Dtr (%)
Oscillator frequency fOSC (Hz) Oscillator frequency fOSC (Hz)
Duty Dtr (%)
Duty vs. oscillator frequency (ch4)
Output sink current setting resistor RB (kΩ)
Output sink current IO (mA)
Output sink current vs.
output sink current setting resistor
MB3825A
17
(Continued)
40
20
0
−20
−40
1 k 10 k 100 k 1 M 10 M
AV
φ
Ta = +25 °C180
90
0
−90
−180
−
+
+OUT
240 kΩ
2.4 kΩ
4.7 kΩ
4.7 kΩ
VCC = 6 V
VREF
CS
IN − +
10 µF39
26 38
40
20
0
−20
−40
1 k 10 k 100 k 1 M 10 M
180
90
0
−90
−180
−
+
+
− +
OUT
240 kΩ
VCC = 6 V
3 V
4.7 kΩ
4.7 kΩ
2.4 kΩ
4.7 kΩ
4.7 kΩ6 V
10 µF
IN
AV
φ
Ta = +25 °C
16
15
817
1000
800
600
400
200
0
−50 −25 0 25 50 75 100
Power dissipation vs. ambient temperature
Power dissipation PD (mW)
Ambient temperature Ta ( °C)
Error amplifier gain and phase vs. frequency (ch1)
Gain AV (dB)
Frequency f (Hz)
Phase φ (deg)
Error amplifier gain and phase vs. frequency (ch5)
Gain AV (dB)
Frequency f (Hz)
Phase φ (deg)
MB3825A
18
■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
inter nal circuits of the IC. The reference voltage of up to 1 mA 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 wavefor m (CT : amplitude 1.0 V to 1.4 V, CT1 : amplitude 0.65 V to
1.35 V in phase with CT1, and CT2 : amplitude 0.65 V to 1.35 V in inv erse phase with CT) . The triangular wa v e
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 v oltage 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 terminal to the inver ted input
terminal, 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 in v erted input and two non-inv erted inputs (channel 3) , and voltage
pulse width modifier to control output duty according to input voltage.
In the interval when the error amplifier output v oltage 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 v oltage is lower than the triangular wa vef orm, 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 terminal.
2. Channel Control Function
Channel on and off le v els are dependent on the v oltage le v els of the CTL1 terminal (pin 30) and CTL 2 terminal
(pin 29) .
Table 1 Channel by Channel On/Off Setting Conditions.
* : The power supply current in standby mode is 10 µA or less.
CTL terminal
voltage level On/Off state of channel
CTL1 CTL2 Po wer supply
circuit Channel 1 Channel 2 Channel 4 Channel 5 Channel 6 Channel 3
L X OFF (standby mode) *
HLON OFF
HON
MB3825A
19
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 shor t detection voltage, or the SCP ter minal (pin 13) voltage falls below the reference
v oltage, the timer circuit starts operating and the capacitor CSCP connected to the CSCP terminal (pin 23) starts
charging.
When the capacitor charge reaches appro ximately 0.7 V, the output tr ansistor 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 mal-
function, resulting in system breakdown or system deterioration. By detecting the internal reference v oltage with
respect to the pow er supply v oltage, 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 le vel, and operates the timer-latch short protection circuit if any of the output circuit power
supplies fall below Vcc − 0.65 V.
MB3825A
20
■METHODS OF SETTING THE OUTPUT VOLTAGE
Figure 1. CH1 to CH4
−
+
−
+
+
39
40
VO
R1
R2
R3 −IN (E) 1
IN (C) 1
Error
Amp1
SCP
Comp1
1.5 V
1.5 V
VO >R2 + R3
1.5 V (R1 + R2 + R3)
(R1 + R2 + R3)
VO =1.5 V
R3
−
+
+
−
+
8
15
14
16
17
R2
R1
VOFB5
−IN (E)5
IN (C) 5
+IN (E) 5
OVP5, 6
0.6 V SCP
Comp5
Error
Amp5
VO = VOVP5, 6
R2 (R1 + R2)
VO = V+IN (E) 5
R2 (R1 + R2)
VOVP5, 6 > V+IN (E) 5
VOVP5, 6 < V+IN (E) 5
Figure 2. CH5 and CH6
Motor
control
signal
MB3825A
21
■METHOD OF SETTING THE OUTPUT CURRENT
Figure 3 shows the configur ation of the output circuits, and Figure 4 illustrates ho w the sink current v alue of the
output current wa v ef orm has a constant current setting. Note that the sink current is set by the f ollo wing f ormula
• Sink current = (VB/RB) × 60 56/RB [A]
× 60
× 1
GND (O)
CB2
10 kΩ
100 kΩ
VCC(O)
CB1
OUT1
RB
VB
VB
External PNP transistor
Sink current
Source
current
Output ON
base current
speed-up
Output OFF
driver
To PWM
comparator
Figure 3. Output circuit (main side)
0
t
Source current (peak)
Speed-up current
Output current
Sink current
Figure 4. Output current waveform
MB3825A
22
Note :
Output current setting resistance RB1 to RB6 should be connected to each channel as shown in Figure 5 belo w .
• 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.
■OSCILLATOR FREQUENCY SETTING
The oscillator frequency can be set by connecting a timing capacitor (CT) to the CT terminal (pin 22) and a timing
resistor (RT) to the RT terminal (pin 21) .
Oscillator frequency : fOSC
MB3825A
VCC(O) 1, 3
VB1
VB3
VCC(O) 2
VB2
VCC(O) 4, 5, 6
VB4
VB5
VB6
RB1
RB3
RB2
RB4
RB5
RB6
Figure 5. Output sink current setting pin connections
fOSC (kHz) 1950000
CT (pF) •RT (kΩ)
MB3825A
23
■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 50 mV) .
If the load conditions change rapidly due to a shor t-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 terminal 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 (s) 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 terminal
is held at input latch voltage (VI 50 mV) .
A
13
R3
R2
R1
IN (C) 1
SCP
−
+
−
+
40
1.5 V
1.5 V
SCP
Comp.1
SCP
Comp.
26
23
CSCP
CSCP
Q1 Q3
1 µA
−
+
1.5 V
UVLO Ref Power
ON/OFF
Soft Start
Comp.
Q2
CS
SR
1 µA
Buff
29
28
30
27
OUT1-6
OUT1-3
OUT2-1
OUT1-1
CTL2
CTL1
VCC
VREF
4
56
43
46
bias
bias
External PNP transistor
Output
stage
Output
stage
Output
stage
Output
stage
Timer-latch
short circuit
protection circuit
Figure 6. Protection timer-latch short protection circuit
MB3825A
24
■TREATMENT WITHOUT USING CSCP
When you do not use the timer-latch shor t protection circuit, connect the CSCP ter minal (pin 23) to GND with
the shortest distance.
23
24
25
CSCP
GND1
GND2
Figure 7. Treatment when not using CSCP
MB3825A
25
■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
v oltage) , transistors Q2 s witches 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 (s) 1.5 × CS (µF) .
A
R3
R2
R1
−IN (E)1
1.5 V
Error
Amp1
26
23
CSCP
CSCP
Q1
1 µA
−
+
−
+
+
1.5 V
UVLO
Soft Start
Comp.
Q2
CS
1 µA
Buff
29
OUT1-6
OUT1-3
OUT2-1
OUT1-1
CTL2
4
56
43
46
38
FB1
CS
SCP
39
Ref Power
ON/OFF
28
30
27CTL1
VCC
VREF
bias
Output
stage
Output
stage
Output
stage
Output
stage
External PNP transistor
Figure 8. Soft-start circuit
MB3825A
26
• Channel 3
The capacitor CDTC3 is placed between the DTC3 terminal (pin 31) and GND, so that when the CTL2 ter minal
(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 shor t detection function is not tur ned off dur ing soft-start operation, this setting should be made under
the following condition.
Channel 3 soft-start circuit time < Short detection time
A
−
+
−
+
32
33
FB3
−IN (E) 3
IN (C) 3
1.5 V
1.5 V
H : ON (CH3) CTL2
L : OFF 29
34
Error
Amp.3
Ra
Rb
34
CDTC3
DTC3
SCP
Comp.3
+
+
−
PWM
Comp.3
56
OUT1-3
Q4
External PNP transistor
Output
stage
To CSP To UVLO
To CT1
To VREF
Figure 9. Channel 3 soft-start circuit
MB3825A
27
■PROCESSING WITHOUT USING CS TERMINAL
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) .
26 CS
Open
Figure 10. When no soft-start time is set (1, 2, 4 channel)
27
31
VREF
DTC3
Figure 11. When no soft-start time is set (3 channel)
MB3825A
28
■METHOD OF SETTING THE DEAD TIME
When the de vice 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
ON-duty) 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.
When you do not use this DTC3 terminal, connect then to VREF terminal (pin 27) as shown Figure.13..
Duty (ON) MAX Vdt − 0.65
0.7 × 100 [%]
27
31
VREF
DTC3
Vdt Rb
Ra
Figure 12. When using DTC to set dead time
27
31
VREF
DTC3
Figure 13. When not using DTC to set dead time
MB3825A
29
■APPLICATION EXAMPLE
•General view
A
38
39 45
44
40
B
FB1
1.5 V
−
+
+
−
+
+
+
−
+
−
−
+
−
+
−
+
Error
Amp.1
SCP
Comp.1
−IN(E)1
IN(C)1
FB2
−IN(E)2
1.5 V
70 mV
PWM
Comp.1-2
PWM
Comp.1-1
Drive
1-1
Drive
1-2
46
41
43
51
<CH1> 42VCC(O)1, 3
CB1-1
CB2-1
OUT1-1
OUT2-1
VB1
VO1(3.2 V)
A
VO2(5.05 V)
B
VO4(4.89 V)
D
VO3(15 V)
C
36
37
35
1.5 V
1.5 V
SCP
Amp.2
<CH2>
<CH3>
<CH4>
<CH5>
<CH6>
Drive
2
Drive
3
Drive
4-1
Drive
4-2
50
47
48
49
54
55
56
52
53
VCC(O)2
CB2-2
560 pF
560 pF
CB1-2
OUT1-2
CB1-3
CB2-3
59
63
58
57
62
2
1
3
CB1-4
CB2-4
OUT1-4
VB4
OUT2-4
CB1-5
CB2-5
6
5
CB1-6
CB2-6
VB6
GND(O)4, 5, 6
OUT1-6
VB5
OUT1-5
OUT1-3
VB3
GND(O)1, 2, 3
VB2
Error
Amp.2 PWM
Comp.2
PWM
Comp.3
IN(C)2
C
−
+
−
+
−
+
−
+
+
−
+
−
+
−
FB3
CTL2
−IN(E)333
29
34
31
32
1.5 V
1.5 V
1.5 V
1.5 V
1.5 V
Error
Amp.3
Error
Amp.4
Error
Amp.5
SCP
Comp.5
SCP
Comp.4
IN(C)3
D
FB4
−IN(E)419
18
20
IN(C)4
EFB5
−IN(E)5
16
15
14
17
IN(C)5
H : ON(CH3)
L : OFF
SCP
Comp.3
+
−
+
DTC3
−
+
+
−
+
+
70 mV
PWM
Comp.4-1
PWM
Comp.4-2
VO5(4.5 V)
E
VCC(O)4, 5, 6
60
VO6(4.5 V)
F
Drive
5 64
PWM
Comp.6
PWM
Comp.5
0.6 V
−
+
−
+
−
+
+
−
−
−
−
+
Error
Amp.6
SCP
Comp.6
SCP
Comp.
FFB6
−IN(E)611
10
9
13
8
12
IN(C)6
−
+
+
0.6 V
+IN(E)5
+IN(E)6
OVP5, 6
VIN
(6 V)
7
61
28
30
25
24
27
22
VCC
Comp.
0.65 V
SCP
26
CS
CSCP
Buff
1 µA
1 µA
1.5 V
Soft Start
Comp.
23
SCP UVLO OSC Ref Power
ON/OFF
−1.35 V
−0.65 V
−1.35 V
−0.65 V VCC
CTL1
GND2GND1
1.5 V
VREF
21
RT CT
0.033 µF
0.033 µF
0.033 µF
0.033 µF
0.033 µF
0.033 µF
VFB1 VOUT1-1
VOUT2-1
VC1
VO1
560 pF
22 kΩ
22 kΩ
22 kΩ
22 kΩ
22 kΩ
22 kΩ
10 µH
10 µH
4.7 µF
4.7 µF
10 µH4.7 µF
U1FWJ44N
U1FWJ44N
6.8 µF
68 µH
33 µH
30 Ω
2SK2316
13.5 kΩ
3.5 kΩ
15 kΩ
23.5 kΩ
12 kΩ
15 kΩ
42.5 kΩ
2.5 kΩ
5 kΩ
13.5 kΩ
7.5 kΩ
9.3 kΩ
30 kΩ
15 kΩ
30 kΩ
15 kΩ
30 kΩ
120 kΩ
FMMT717
FMMT717
6.8 µF50 Ω
750 Ω
2.2 µF
2SB1121 1SS196
560 pF FMMT717
2SK2316 50 Ω
U1FWJ44N
6.8 µF
33 µH
100 Ω
FMMT717
FMMT717
U1FWJ44N
2.2 µF
560 pF
560 pF
47 µH
100 Ω
2.2 µF
47 µH
U1FWJ44N
Drive
6 4
10 µH
4.7 µF
VCT
100 pF
39 kΩ
0.1 µF
0.1 µF
A
B
C
Over voltage
threshold
setting
voltage
FMMT717 : ZETEX plc.
2SB1121 : SANYO Electric Co., Ltd.
2SK2316 : SANYO Electric Co., Ltd.
1SS196 : TOSHIBA CORPORATION
U1FWJ44N : TOSHIBA CORPORATION
H : ON (CH1, 2, 4 to 6)
L : OFF (standby state)
MB3825A
30
•Enlarged view of A
A
38
39 45
44
40
B
FB1
1.5 V
−
+
+
−
+
+
+
−
+
−
−
+
−
+
−
+
Error
Amp.1
SCP
Comp.1
−IN(E)1
IN(C)1
FB2
−IN(E)2
1.5 V
70 mV
PWM
Comp.1-2
PWM
Comp.1-1
Drive
1-1
Drive
1-2
46
41
43
51
<CH1> 42VCC(O)1, 3
CB1-1
CB2-1
OUT1-1
OUT2-1
VB1
VO1(3.2 V)
A
VO2(5.05 V)
B
36
37
35
1.5 V
1.5 V
SCP
Amp.2
<CH2>
Drive
2 50
47
48
49
VCC(O)2
CB2-2
560 pF
CB1-2
OUT1-2
VB2
Error
Amp.2 PWM
Comp.2
IN(C)2
0.033 µF
0.033 µF
VFB1 VOUT1-1
VOUT2-1
VC1
VO1
560 pF
22 kΩ
22 kΩ
10 µH
10 µH
4.7 µF
4.7 µF
U1FWJ44N
U1FWJ44N
6.8 µF
68 µH
33 µH
30 Ω
2SK2316
13.5 kΩ
3.5 kΩ
15 kΩ
23.5 kΩ
12 kΩ
15 kΩ
FMMT717
FMMT717
6.8 µF50 Ω
FMMT717 : ZETEX plc.
2SB1121 : SANYO Electric Co., Ltd.
2SK2316 : SANYO Electric Co., Ltd.
1SS196 : TOSHIBA CORPORATION
U1FWJ44N : TOSHIBA CORPORATION
H : ON (CH1, 2, 4 to 6)
L : OFF (standby state)
MB3825A
31
•Enlarged view of B
VO4(4.89 V)
D
VO3(15 V)
C
<CH3>
<CH4>
Drive
3
Drive
4-1
Drive
4-2
54
55
56
52
53
560 pF
CB1-3
CB2-3
59
63
58
57
62
CB1-4
CB2-4
OUT1-4
VB4
OUT2-4
OUT1-3
VB3
GND(O)1, 2, 3
PWM
Comp.3
C
−
+
−
+
−
+
+
−
+
−
FB3
CTL2
−IN(E)333
29
34
31
32
1.5 V
1.5 V
1.5 V
1.5 V
Error
Amp.3
Error
Amp.4
SCP
Comp.4
IN(C)3
D
FB4
−IN(E)419
18
20
IN(C)4
H : ON(CH3)
L : OFF
SCP
Comp.3
+
−
+
DTC3
−
+
+
70 mV
PWM
Comp.4-1
PWM
Comp.4-2
VCC(O)4, 5, 6
60
0.033 µF
0.033 µF
22 kΩ
22 kΩ
10 µH4.7 µF
42.5 kΩ
2.5 kΩ
5 kΩ
13.5 kΩ
7.5 kΩ
9.3 kΩ
30 kΩ
120 kΩ
750 Ω
2.2 µF
2SB1121 1SS196
560 pF FMMT717
2SK2316 50 Ω
U1FWJ44N
6.8 µF
33 µH
FMMT717 : ZETEX plc.
2SB1121 : SANYO Electric Co., Ltd.
2SK2316 : SANYO Electric Co., Ltd.
1SS196 : TOSHIBA CORPORATION
U1FWJ44N : TOSHIBA CORPORATION
H : ON (CH1, 2, 4 to 6)
L : OFF (standby state)
MB3825A
32
•Enlarged view of C
<CH5>
<CH6>
2
1
3
CB1-5
CB2-5
6
5
CB1-6
CB2-6
VB6
GND(O)4, 5, 6
OUT1-6
VB5
OUT1-5
−
+
+
−
1.5 V
Error
Amp.5
SCP
Comp.5
EFB5
−IN(E)5
16
15
14
17
IN(C)5
−
+
+
VO5(4.5 V)
E
VO6(4.5 V)
F
Drive
5 64
PWM
Comp.6
PWM
Comp.5
0.6 V
−
+
−
+
−
+
+
−
−
−
−
+
Error
Amp.6
SCP
Comp.6
SCP
Comp.
FFB6
−IN(E)611
10
9
13
8
12
IN(C)6
−
+
+
0.6 V
+IN(E)5
+IN(E)6
OVP5, 6
VIN
(6 V)
7
61
28
30
25
24
27
22
VCC
Comp.
0.65 V
SCP
26
CS
CSCP
Buff
1 µA
1 µA
1.5 V
Soft Start
Comp.
23
SCP UVLO OSC Ref Power
ON/OFF
−1.35 V
−0.65 V
−1.35 V
−0.65 V VCC
CTL1
GND2GND1
1.5 V
VREF
21
RT CT
0.033 µF
0.033 µF
22 kΩ
22 kΩ
30 kΩ
15 kΩ
30 kΩ
15 kΩ
100 Ω
FMMT717
FMMT717
U1FWJ44N
2.2 µF
560 pF
560 pF
47 µH
100 Ω
2.2 µF
47 µH
U1FWJ44N
Drive
6 4
10 µH
4.7 µF
VCT
100 pF
39 kΩ
0.1 µF
0.1 µF
FMMT717 : ZETEX plc.
2SB1121 : SANYO Electric Co., Ltd.
2SK2316 : SANYO Electric Co., Ltd.
1SS196 : TOSHIBA CORPORATION
U1FWJ44N : TOSHIBA CORPORATION
H : ON (CH1, 2, 4 to 6)
L : OFF (standby state)
Over voltage
threshold
setting
voltage
MB3825A
33
■REFERENCE DATA
6
4
2
0
VC1 (V)
012345
t (µs)
VIN = 6 V
RL = 30 Ω
CT = 100 pF
RT = 39 kΩ
3
2
1
0
VC1 (V)
0 0.4 0.8 1.2 1.6 2.0
t (µs)
Synchronous rectifier length
expansion
150 ns 120 ns
Channel 1 switching operation waveform (operation at 500 kHz)
MB3825A
34
(Continued)
Channel 1 main side output waveform (operation at 500 kHz)
6
4
2
0
1.0
0.5
0
VC1 (V)
VCT (V)
VFB1 (V)
012345
t (µs)
VIN = 6 V
RL = 30 Ω
CT = 100 pF
RT = 39 kΩ
VC1
VCT
VFB1
Channel 1 main side base current waveform (operation at 500 kHz)
1.0
0.5
0
40
20
0
−20
−40
−60
−80
60
−100
VCT (V)
VFB1 (V)
012345
t (µs)
IOUT1-1 (mA)
IOUT1-1
VCT
VFB1
VIN = 6 V
RL = 30 Ω
CT = 100 pF
RT = 39 kΩ
Peak current when turned ON 42 mA
Peak current when turned OFF 50 mA
MB3825A
35
(Continued)
6
4
2
0
6
4
2
0
VC1 (V)
VOUT2-1 (V)
012345
t (µs)
VIN = 6 V
RL = 30 Ω
CT = 100 pF
RT = 39 kΩ
Channel 1 synchronous rectifier side output waveform (operation at 500 kHz)
40
60
20
0
−20
−40
2
4
0
IOUT2-1 (mA)
VOUT2-1 (V)
012345
t (µs)
VIN = 6 V
RL = 30 Ω
CT = 100 pF
RT = 39 kΩ
Channel 1 synchronous rectifier side output waveform (operation at 500 kHz)
Output source current peak value 30 mA
Output sink current peak value 52 mA
MB3825A
36
■NOTES ON USE
• Take account of common impedance when designing the earth line on a printed wiring board.
• Take measures against static electricity.
- For semiconductors, use antistatic or conductive containers.
- When storing or carrying a printed circuit board after chip mounting, put it in a conductive bag or container.
- The work table, tools and measuring instruments must be grounded.
- The worker must put on a grounding device containing 250 kΩ to 1 MΩ resistors in series.
• Do not apply a negative voltage
- Applying a negative voltage of −0.3 V or less to an LSI may generate a parasitic transistor, resulting in
malfunction.
■ORDERING INFORMATION
Part number Package Remarks
MB3825APFV 64-pin plastic LQFP
(FPT-64P-M03)
MB3825APFF 64-pin plastic LQFP
(FPT-64P-M20)
MB3825A
37
■PACKAGE DIMENSION
64-pin Plastic LQFP
(FPT-64P-M03)
Note 1)* : These dimensions do not include resin protrusion.
Note 2)Pins width and pins thickness include plating thickness.
Note 3)Pins width do not include tie bar cutting remainder.
Dimensions in mm (inches) .
Note : The values in parentheses are reference values.
LEAD No.
Details of "A" part
0.25(.010)
(Stand off)
(.004±.004)
0.10±0.10
(.024±.006)
0.60±0.15
(.020±.008)
0.50±0.20
1.50 +0.20
–0.10
+.008
–.004
.059
0˚~8˚
"A"
0.08(.003)
(.006±.002)
0.145±0.055
0.08(.003) M
(.008±.002)
0.20±0.05
0.50(.020)
12.00±0.20(.472±.008)SQ
10.00±0.10(.394±.004)SQ
INDEX
49
64
3348
17
32
161
2003 FUJITSU LIMITED F64009S-c-5-8
C
(Mounting height)
*
MB3825A
38
64-pin Plastic LQFP
(FPT-64P-M20)
Dimensions in mm (inches) .
Note : The values in parentheses are reference values.
2000 FUJITSU LIMITED F64031S-1c-1
C
0.50±0.20
(.020±.008)
Details of "A" part
"A"
0.10(.004)
1 16
32
17
48 33
64
49
0.40(.016) 0.16±0.03
(.006±.001)
7.00±0.20(.276±.008)SQ
9.00±0.20(.354±.008)SQ
INDEX
3.5°±3.5°
(1.00(.039))
0.10±0.10
(.004±.004)
1.40±0.10
(.055±.004)
1.60(.063)MAX
0.127(.005)
MB3825A
FUJITSU LIMITED
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F0308
FUJITSU LIMITED Printed in Japan