FUJITSU MB3841

FUJITSU SEMICONDUCTOR
DATA SHEET
DS04-27603-1E
ASSP For Power Supply Applications
Power Management Switch IC
MB3841
■ DESCRIPTION
The FUJITSU MB3841 is a one-channel power management switch IC with extremely low on resistance.
The MB3841 is designed for a variety of switching applications, featuring operation from low input voltages
(VIN > 2.2 V) and stable on resistance that does not depend on input voltage. The switch current limit can be
externally set over a wide range from 100 mA to 2 A. A safety function detects overcurrent conditions, immediately
sets the switch to off mode and sends an external notification signal. The MB3841 is therefore ideal for power
management switching applications with USB specifications.
In addition, the MB3841 has features that ensure accurate on-off switching by preventing reverse current in off
mode, as well as rapid discharge of capacitors connected to output.
■ FEATURES
•
•
•
•
•
•
•
•
•
•
Low on resistance switch (typ. 45 mΩ)
Low input voltage operation (2.2 V to 5.5 V)
Switch current (max. 2 A)
UVLO (VTH = 1.9 V)
External settings for soft start time and switch current limit
On-chip overheating and overcurrent detection (output off latching)
On-chip abnormal state detection circuit (O.C. pin)
On-chip output pin discharge control circuit
Supply current = 0 µA in standby mode (CONTROL < 0.8 V)
Reverse current protection function in off mode
■ PACKAGE
8-pin Plastic SOP
(FPT-8P-M01)
MB3841
■ PIN ASSIGNMENT
CONTROL
O.C
SS
GND
CURRENT
VCC
VIN
OUT
(TOP VIEW)
2
MB3841
■ PIN DESCRIPTION
Pin no.
Symbol
1
CONTROL
2
SS
3
CURRENT
4
VIN
Descriptions
Control signal input pin. Set “H” to turn the switch on, “L” to turn the switch off.
At 0.8 V or less, the chip is in STBY state and current consumption is less
than1µA.
Slow start setting pin. Used to adjust the switch on/off timing.
Add external capacitance to delay operation. Leave open when not in use.
In open mode voltages up to 10 V are present. Care should be taken in mounting
to prevent leak current generation because high impedance is required.
Current limit setting pin. The limit current level is set by connecting this pin to
external resistance.
If this pin is connected to GND, no current limit is applied.
Switch input pin.
The VIN voltage monitoring function enables switch operation at 1.9 V or higher.
If the VIN voltage drops to 1.8 V or lower switch operation is disabled.
5
OUT
Switch output pin.
The discharge function will immediately discharge the capacitance charge
connected to the OUT pin when the switch is in off position and 350 Ω resistance
(with VCC = 5 V) is connected to the GND terminal.
6
VCC
Control power supply input pin. This pin supplies power to the control circuit.
The input voltage level must be stable.
7
GND
Ground pin.
O.C
External signal pin.
When the switch is in on mode this pin normally outputs a “H” level signal, but
changes to “L” level when an overcurrent, overheating, or UVLO condition is
detected.
When the switch is in off mode this signal is output at “L” level at all times.
This is an open drain connection, and should be pulled up to high potential using
resistance.
8
3
MB3841
■ BLOCK DIAGRAM
VIN
OUT
SW
CURRENT
load current
detection
Charge pump
SS
+
COMP
−
OSC
Temperature
(HYS)
protection
Q
S
+
COMP
FF
−
R
VCC
BGR
+
CONTROL
COMP
−
(HYS)
DISCHARGE
O.C
GND
4
MB3841
■ ABSOLUTE MAXIMUM RATINGS
Parameter
Symbol
Condition
Input voltage
VIN
Power supply voltage
Rating
Unit
Max.
Min.
—
–0.3
7.0
V
VCC
—
–0.3
7.0
V
Control voltage
VCTL
—
–0.3
7.0
V
Switch current
ISW
VIN = 2.2 V to 5.5 V, Ta = +25°C
—
3 A (DC)
A
Allowable dissipation
PD
Ta = +85°C
—
280
mW
Storage temperature
TSTG
—
–55
+125
°C
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
Condition
Input voltage
VIN
Power supply voltage
VCC
Control voltage
VCTL
Switch current
ISW
SS pin capacitance
CSS
Current limit
resistance
RLIN
O.C sync current
IOC
Operating
temperature
TOP
Value
Unit
Min.
Typ.
Max.
—
0
—
5.5
V
—
0
—
5.5
V
0
—
5.5
V
VIN = 2.2 V to 5.5 V,
VCTL = 2.2 V to 5.5 V
—
—
2.0
A
—
—
—
10
nF
VIN = 5.0 V (ISW = 2 A to 0.1 A)
1.8
—
24
kΩ
VIN = 2.2 V (ISW = 2 A to 0.1 A)
2.2
—
51
kΩ
—
—
1.0
mA
–20
—
+85
°C
VCTL
VCC
VIN = 2.2 V to 5.5 V, VCC
—
2.2 V
Note: For CSS, RLIN settings, see p. 9.
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.
5
MB3841
■ ELECTRICAL CHARACTERISTICS
(VIN = 5 V, VCC = 5 V, Ta = +25°C)
Parameter
Switch resistance
IN pin disable current
VCC power supply current
UVLO threshold
UVLO histeresis spread
CONTROL pin input current
CONTROL pin threshold
CONTROL pin histeresis
spread
Symbol
Min.
Typ.
Max.
Unit
VIN = 5 V, VCTL = 3 V, ISW = 2 A
—
45
70
mΩ
IIN1
VIN = 5 V, VCTL = 3 V, ISW = 0 A
—
170
340
µA
IIN2
VIN = 5 V, VCTL = 3 V, ISW = 2 A
—
0.9
1.8
mA
IIN3
VIN = 5 V, VCTL = 0.4 V
—
—
1.0
µA
ICC1
VIN = 5 V, VCTL = 3 V, ISW = 2 A
—
105
210
µA
ICC2
VIN = 5 V, VCTL = 0.4 V
—
—
1.0
µA
VIUH
VCC = 5 V, VIN at O.C. = L → H
1.7
1.9
2.1
V
VIUL
VCC = 5 V, VIN at O.C. = H → L
1.6
1.8
2.0
V
VIUHY
VIUHY = VIUH – VIUL
50
100
150
mV
VCTL = 5 V, ISW = 0 A
—
5.0
10
µA
VTHCTL
VCC = 2.2 V, VCTL at O.C. = L → H
1.2
1.35
1.5
V
VTLCTL
VCC = 2.2 V, VCTL at O.C. = H → L
1.0
1.15
1.3
V
VCTLHY
VCTLHY = VTHCTL – VTLCTL
100
200
300
mV
RLIM = 24 kΩ, VCTL = 2.2 V
73
105
137
mA
RLIM = 1.8 kΩ, VCTL = 2.2 V
1.57
1.97
2.37
A
RLIM = 51 kΩ, VCTL = 2.2 V
68
98
128
mA
RLIM = 2.2 kΩ, VCTL = 2.2 V
1.53
1.92
2.31
A
ICTL
ISWLH1
ISWLL2
ISWLH2
VIN = 5 V
VIN = 2.2 V
O.C sync current
IOCS
VCC = 5 V, VCTL = 0.8 V, VOC = 0.4 V
1.0
—
—
mA
O.C leak current
IOCL
VCC = 5 V, VCTL = 3 V, VOC = 5.0 V
—
—
2.0
µA
Switch discharge
resistance
RDCG
VCC = 5 V, VCTL = 0.8 V, VOUT = 5.0 V
—
350
700
Ω
Temperature protection (Tj)
TLIM
VCC = 5 V, VCTL = 2.2 V
+125
—
—
°C
tON1
VCC = 5 V, VIN = 5 V, SS, OUT: Open
—
300
900
µs
tON2
VCC = 5 V, VIN = 2.2 V, SS, OUT: Open
—
610
1830
µs
tOFF1
VIN = 5 V, VCC = 5 V, SS, OUT: Open
—
10
50
µs
tOFF2
VIN = 5 V, VCC = 2.2 V, SS, OUT: Open
—
50
250
µs
OUT pin rise time
OUT pin fall time
6
Value
RON
ISWLL1
Switch current limit
Condition
MB3841
■ DIAGRAM
1. Normal operation
VCC
VIN
CONTROL
1.35 V
1.15 V
90%
VOUT
10%
90%
tON
10%
tOFF
O.C
DISCHARGE logic
ON
OFF
ON
2. At VIN Fall
VCC
VIN
1.9 V
1.8 V
CONTROL
VOUT
O.C
DISCHARGE logic
ON
OFF
7
MB3841
3. At VOUT short
VCC
VIN
CONTROL
1.15 V
VOUT
O.C
Over current latch
Latch set
Latch release
DISCHARGE logic
ON
8
OFF
ON
MB3841
■ TYPICAL CHARACTERISTICS
1. RLIM vs. Limit Current Characteristics
RLIM – lSW
ISW(A)
10
VIN = 2.2 V
VIN = 3.3 V
VIN = 5 V
1
0.1
1000
10000
100000
RLIM (Ω)
2. CSS vs. TON (SS) Characteristics
CSS – tON
100
tON (msec)
10
VIN = 2.2 V
VIN = 3.3 V
VIN = 5 V
1
0.1
100
1000
10000
CSS (pF)
9
MB3841
3. SW Resistance Temperature Characteristics
Temperature dependency of SW resistance (VIN = 5 V, lOUT = 2 A, Ta: Ambient temperature)
100
90
80
SW resistance (mΩ)
70
60
50
40
30
20
10
0
−60
−40
−20
0
20
40
60
80
100
120
Ta (°C)
VIN voltage dependency of SW resistance (lOUT = 2 A, Ta = −40, +25, +100°C)
100
90
80
SW resistance (mΩ)
70
60
−40°C
+25°C
50
+100°C
40
30
20
10
0
2
3
4
5
VIN (V)
10
6
7
MB3841
■ FUNCTIONAL DESCRIPTION
Current Limit Setting
The MB3841 provides highly accurate switching current setting, in the range 100 mA to 2 A ±20% (with limit
setting current at 2 A) by placing resistance between the CURRENT and GND pins.
Because the setting is dependent on the VIN voltage, it is important that the appropriate resistance be connected
to the VIN pin.
The following approximation formula (1) may be used to calculate the limit setting when VIN = 5V.
For details, see “RLIM vs. Limit Current Characteristics” on p. 9.
ISW =
7450
(RLIM[Ω])1.1
[A]
.... (1)
When the switch limit level is exceeded, the switch turns off and then latch is set to protect the device.
At the same time the O.C output signal goes to “L” level to notify external systems.
When a “L” level signal is applied to the CONTROL switch, the latch is released, so that normal operation is
resumed at the next “H” level signal to the CONTROL switch.
Thermal Shutdown
The MB3841 has a thermal shutdown function which turns the switch off and sets the latch to protect the device
when junction temperature exceeds 125°C.
At the same time the O.C output signal goes to “L” level to notify external systems.
When a “L” level signal is applied to the CONTROL switch, the latch is released,so that normal operation is
resumed at the next “H” level signal to the CONTROL switch.
Slow Start
The on/off switching time of the MB3841 can be delayed by applying capacitance between the SS and GND
pins. Controlling the on time can soften surge current to the load side capacitance when power is turned on.
(tON, tOff are measured at 90% of VOUT.)
The following approximation formula (2) may be used to set on time when VIN = 5 V.
For details, see “Css vs. tON (SS) Characteristics” on p. 9.
tON = 0.87 × 10–3 × CSS[pF] + 0.3 [ms] .... (2)
DISCHARGE
The MB3841 has a DISCHARGE pin function that immediately discharges electric charge on the load side when
the switch is turned off.
11
MB3841
■ TYPICAL APPLICATION
Pull up resistance
Control signal
CONTROL
O.C
CSS
SS
GND
RLIM
CURRENT
VIN
12
VCC
OUT
load
MB3841
■ SAMPLE APPLICATIONS
(1) Bus Supplied Hub (GANG Mode Connection)
Bus Supply (Up-board)
5V
USB controller
MB3841
CONTROL
O.C
CSS
SS
GND
Pull up resistance
RLIM
CURRENT
VIN
VCC
Down-port
OUT
100 mA max/port
13
MB3841
(2) Self Supplied Hub (NON-GANG Mode Connection)
USB controller
MB3841
CONTROL
Pull up
resistance
O.C
CSS
SS
Self supply
RLIM
GND
CURRENT
VCC
Down-port
5V
VIN
OUT
500 mA max
3.3 V
MB3841
CONTROL
O.C
CSS
SS
RLIM
GND
CURRENT
Pull up
resistance
VCC
Down-port
VIN
OUT
500 mA max
MB3841
CONTROL
O.C
CSS
SS
RLIM
GND
CURRENT
Pull up
resistance
VCC
Down-port
VIN
OUT
500 mA max
MB3841
CONTROL
O.C
Pull up resistance
CSS
SS
RLIM
CURRENT
GND
VCC
Down-port
VIN
OUT
500 mA max
14
MB3841
■ USAGE PRECAUTION
1. Never use settings exceeding maximum rated conditions.
Exceeding maximum rated conditions may cause permanent damage to the LSI.
Also, it is recommended that recommended operating conditions be observed in normal use.
Exceeding recommended operating conditions may adversely affect LSI reliability.
2. Use this device within recommended operating conditions.
Recommended operating conditions are values within which normal LSI operation is warranted.
Standard electrical characteristics are warranted within the range of recommended operating conditions and
within the listed conditions for each parameter.
3. Printed circuit board ground lines should be set up with consideration for common
impedance.
4. Take appropriate static electricity measures.
•
•
•
•
Containers for semiconductor materials should have anti-static protection or be made of conductive material.
After mounting, printed circuit boards should be stored and shipped in conductive bags or containers.
Work platforms, tools, and instruments should be properly grounded.
Working personnel should be grounded with resistance of 250 kΩ to 1 mΩ between body and ground.
5. Do not apply negative voltages.
The use of negative voltages below –0.3 V may create parasitic transistors on LSI lines, which can cause
abnormal operation.
■ ORDERING INFORMATION
Part number
MB3841 PF-G-BND
Package
Remarks
8-pin Plastic SOP
(FPT-8P-M01)
15
MB3841
■ PACKAGE DIMENSION
8-pin Plastic SOP
(FPT-8P-M01)
2.25(.089)MAX
+0.25
+.010
6.35 –0.20 .250 –.008
0.05(.002)MIN
(STAND OFF)
5.30±0.30
(.209±.012)
INDEX
1.27(.050)
TYP
0.45±0.10
(.018±.004)
3.81(.150)REF
+0.40
6.80 –0.20
+.016
.268 –.008
7.80±0.40
(.307±.016)
+0.05
Ø0.13(.005)
M
0.15 –0.02
+.002
.006 –.001
0.50±0.20
(.020±.008)
Details of "A" part
0.20(.008)
0.50(.020)
"A"
0.18(.007)MAX
0.10(.004)
C
16
1994 FUJITSU LIMITED F08002S-4C-4
0.68(.027)MAX
Dimensions in mm (inches)
MB3841
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
http://www.fmap.com.sg/
F9809
 FUJITSU LIMITED Printed in Japan
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.