Rohm BU90006GWZ Output 1.0a high-efficiency step-down switching regulators with built-in power mosfet Datasheet

Single-chip Type with Built-in FET Switching Regulator Series
Output 1.0A High-efficiency
Step-down Switching regulators with
Built-in Power MOSFET
BU90002GWZ, BU90003GWZ, BU90004GWZ, BU90005GWZ, BU90006GWZ,
No.11xxxEATxx
●Description
The BU9000XGWZ are a high efficiency 6MHz synchronous step-down switching regulator with ultra low current PFM
mode.
It provides up to 1.0A load current and an input voltage range from 3.0V to 5.5V, optimized for battery powered portable
applications.
BU9000XGWZ has a mode control pin that allows the user to select Forced PWM(Pulse Width Modulation)mode or
PFM(Pulse Frequency Modulation) and PWM auto change mode utilized power save operation at light load current.
●Features
1) 93% peak efficiency
2) 4 to 6 MHz switching frequency
3) Input voltage VIN=2.3V to 5.5V(BU90003~BU90006), VIN=4.0V to 5.5V (BU90002)
4) 45uA typical quiescent current
5) Fast transient response
6) Automatic PFM/PWM operation
7) Forced PWM operation
8) Internal Soft Start
9) Under voltage lockout
10) Over current protection
11) Thermal shutdown
12) Ultra small and low profile WLCSP (1.3mm×0.9mm t=0.40mm MAX) (UCSP35L1 )
●Applications
Cell phones, Smart phones, Portable applications and Micro DC/DC modules, USB accessories
●Operating range
Part No.
Output voltage
Input voltage
BU90002GWZ
3.30V
4.0V to 5.5V
BU90003GWZ
1.20V
2.3V to 5.5V
BU90004GWZ
1.80V
2.3V to 5.5V
BU90005GWZ
2.50V
2.3V to 5.5V
BU90006GWZ
3.00V
2.3V to 5.5V
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1/14
Target spec. ver.1.7
BU90002GWZ, BU90003GWZ, BU90004GWZ, BU90005GWZ, BU90006GWZ
Technical Note
●Absolute maximum ratings
Parameter
Maximum input power supply voltage
Symbol
Rating
Unit
VIN
7
V
VEN, VFB,
VLX, VMODE
7
V
Pd
0.39(*1)
W
Operating temperature range
Topr
-40 ~ +85
℃
Storage temperature range
Tstg
-55 ~ +125
℃
Tjmax
+125
℃
Maximum voltage at EN, FB, LX, MODE
Power dissipation
Junction temperature
(*1) When mounted on the specified PCB (55mm x 63mm), Deducted by 3.9m W/c when used over Ta=25c
●Operating conditions Ta=25c, VIN=3.6V(BU90003GWZ~
~BU90006GWZ),VIN=5.0V(BU90002GWZ)
Rating
Item
Symbol
Unit
Condition
Min.
Typ.
Max.
【Switching regulator】
MODE:H(PWM Operation)
-2
+2
VOUTA
%
MODE:L(PWM/PFM Operation)
-2
+3
Output voltage accuracy
3.0V≦VIN<5.5V
IoutMax1
1.0
A
IoutMax2
IoutMax3
-
-
0.8
0.6
A
A
Tss
65
120
240
usec
5.4
6.0
6.6
MHz
4.8
5.4
6.0
MHz
3.6
4.0
4.4
MHz
-
250
300
220
250
400
450
350
380
mOhm
mOhm
mOhm
mOhm
2.7V≦VIN<3.0V
2.3V≦VIN<2.7V
【Soft start】
Soft start time
【Frequency control】
Switching frequency
fosc
No load
BU90002GWZ,BU90005GWZ
BU90006GWZ
No load
BU90004GWZ
No load
BU90003GWZ
【Driver】
RonP1
RonP2
RonN1
RonN2
PchFET on resistance
NchFET on resistance
【Control】
EN pin
control
voltage
-
VIN=5.0V
VIN=3.6V
VIN=5.0V
VIN=3.6V
Operation
VENH
1.4
-
VIN
V
Non Operation
VENL
0
-
0.4
V
Operation
VMODEH
1.4
-
VIN
V
Forced PWM
Non Operation
VMODEL
0
-
0.4
V
Automatic PFM/PWM
Protect threshold voltage
Hysteresis
【Current limit】
Uvth
Uvhy
1.95
50
2.05
100
2.15
150
V
mV
Current limit threshold
ILIMIT
1.5
1.7
1.9
A
【Output discharge】
Output discharge resistance
【Circuit current】
DRES
55
110
220
Ohm
Operating quiescent current
IINS
-
45
65
uA
Shutdown current
SHD
-
0
1
uA
MODE pin
control
voltage
【UVLO】
PMOS current detect,
Open loop
EN=0V
EN:H, MODE:L,
VOUT=3.6V forced
Not switching
EN=0V
○No design for durability against radiation
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© 2011 ROHM Co., Ltd. All rights reserved.
2/14
Target spec. ver.1.7
BU90002GWZ, BU90003GWZ, BU90004GWZ, BU90005GWZ, BU90006GWZ
Technical Note
●Electrical characteristic curves (Reference data)
L:LQM21MPN1R0NG0 (2.0mm×1.6mm×1.0mm Murata)
COUT:GRM155R60J475M(1.0mm×0.5mm×0.5mm Murata)
BU90002GWZ(
(3.3V OUTPUT)
)
EN
2V/div
EN
2V/div
VOUT
2V/div
VOUT
1V/div
20us
IL
500mA/div
100us
Fig.1 Start up
Fig.2 Shut down
Vout
50mV/div
ac coupled
Vout
50mV/div
ac coupled
10us
4us
IOUT
200mA/div
IOUT
50mA/div
Fig.3 Load transient response 5mA to 50mA
tr=tf=100ns, Mode :Low
Fig.4 Load transient response 50mA to 350mA
tr=tf=100ns, Mode :Low
Vout
20mV/div
ac coupled
Vout
50mV/div
ac coupled
400ns
4us
LX
5V/div
IOUT
200mA/div
IL
500mA/div
Fig.5 Load transient response 150mA to 500mA
tr=tf=100ns, Mode :High
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3/14
Fig.6 PFM mode Operation
Iout=40mA
Target spec. ver.1.7
BU90002GWZ, BU90003GWZ, BU90004GWZ, BU90005GWZ, BU90006GWZ
Technical Note
●Electrical characteristic curves (Reference data) – Continued
BU90002GWZ(
(3.3V OUTPUT)
)
MODE
1V/div
Vout
20mV/div
ac coupled
4us
80ns
LX
5V/div
Vout
20mV/div
ac coupled
IL
500mA/div
LX
500mA/div
Fig.7 PFM mode Operation
Iout=100mA
Fig.8 Mode Change Response
MODE High to Low
100
4us
95
MODE
2V/div
Efficiency[%]
90
Vout
20mV/div
ac coupled
85
80
75
70
65
LX
500mA/div
60
1
10
100
1000
Load current[mA]
Fig.10 Efficiency vs Load current
VIN=5V PWM/PFM Auto Mode
3.38
30
3.37
25
Vout Ripple Voltage[mV]
Voltage[V]
Fig.9 Mode Change Response
MODE Low to High
3.36
3.35
Output
3.34
3.33
3.32
3.31
20
15
10
5
0
0
200
400
600
800
1000
0
Load current[mA]
400
600
800
1000
Load current[mA]
Fig.11 Load regulation
VIN=5V PWM/PFM Auto mode
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© 2011 ROHM Co., Ltd. All rights reserved.
200
Fig.12 Vout Ripple Voltage
VIN=5V PWM/PFM Auto Mode
4/14
Target spec. ver.1.7
BU90002GWZ, BU90003GWZ, BU90004GWZ, BU90005GWZ, BU90006GWZ
Technical Note
●Electrical characteristic curves (Reference data)
BU90003GWZ(1.2V OUTPUT)
EN
2V/div
EN
2V/div
VOUT
500mV/div
VOUT
1V/div
40us
100us
IL
200mA/div
Fig.13 Start up
Fig.14 Shut down
Vout
50mV/div
1.2V offset
Vout
50mV/div
1.2V offset
10us
4us
IOUT
200mA/div
IOUT
200mA/div
Fig.15 Load transient response 5mA to 200mA
tr=tf=100ns, Mode :Low
Fig.16 Load transient response 50mA to 350mA
tr=tf=100ns, Mode :Low
Vout
20mV/div
ac coupled
4us
Vout
50mV/div
ac coupled
400ns
LX
2V/div
IOUT
500mA/div
IL
500mA/div
Fig.17 Load transient response 400mA to 1000mA
tr=tf=100ns, Mode :Low
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5/14
Fig.18 PFM mode Operation Iout=50mA
Target spec. ver.1.7
BU90002GWZ, BU90003GWZ, BU90004GWZ, BU90005GWZ, BU90006GWZ
Technical Note
●Electrical characteristic curves (Reference data) – Continued
BU90003GWZ(1.2V OUTPUT)
MODE
2V/div
Vout
50mV/div
ac coupled
2us
80ns
Vout
50mV/div
ac coupled
LX
2V/div
LX
200mA/div
IL
500mA/div
Fig.19 PWM mode Operation Iout=100mA
Fig.20 Mode Change Response
MODE High to Low
100
90
2us
80
MODE
2V/div
Efficiency[%]
70
Vout
50mV/div
ac coupled
60
50
40
VIN=2.7V
30
VIN=3.6V
20
LX
200mA/div
VIN=4.2V
10
0
0.1
1
10
100
1000
Load current[mA]
Fig.22 Efficiency vs Load current
VIN=3.6V PWM/PFM Auto Mode
Fig.21 Mode Change Response
MODE Low to High
1.224
VIN=2.7V
VIN=3.6V
1.212
Vout[V]
VIN=4.2V
1.2
1.188
1.176
1
10
100
1000
Iout[mA]
Fig.23 Load regulation
PWM/PFM Auto mode
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6/14
Target spec. ver.1.7
BU90002GWZ, BU90003GWZ, BU90004GWZ, BU90005GWZ, BU90006GWZ
Technical Note
●Electrical characteristic curves (Reference data)
BU90004GWZ(1.80V OUTPUT)
EN
5V/div
EN
5V/div
VOUT
1V/div
VOUT
1V/div
40us
100us
IL
200mA/div
Fig.25 Shut down
Fig.24 Start up
Vout
50mV/div
ac coupled
Vout
50mV/div
ac coupled
4us
4us
IOUT
200mA/div
IOUT
200mA/div
Fig. 26 Load transient response 5mA to 200mA
tr=tf=100ns, Mode :Low
Vout
50mV/div
ac coupled
Fig.27 Load transient response 50mA to 350mA
tr=tf=100ns, Mode :Low
4us
Vout
50mV/div
ac coupled
400ns
LX
2V/div
IOUT
200mA/div
Fig.28 Load transient response 200mA to 600mA
tr=tf=100ns, Mode :Low
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Fig.29 PFM mode Operation Iout=50mA
Target spec. ver.1.7
BU90002GWZ, BU90003GWZ, BU90004GWZ, BU90005GWZ, BU90006GWZ
Technical Note
●Electrical characteristic curves (Reference data) – Continued
BU90004GWZ(1.80V OUTPUT)
Vout
20mV/div
ac coupled
MODE
5V/div
80ns
4us
Vout
50mV/div
ac coupled
LX
2V/div
LX
200mA/div
Fig.30 PWM mode Operation Iout=100mA
MODE
5V/div
Fig.31 Mode Change Response
MODE High to Low
Efficiency[%]
2us
Vout
50mV/div
ac coupled
LX
200mA/div
100
90
80
70
60
50
40
30
20
10
0
VIN=2.7V
VIN=3.6V
VIN=4.2V
0.1
1
10
100
1000
Load current[mA]
Fig.32 Mode Change Response
MODE Low to High
Fig.33 Efficiency vs Load current
VIN=3.6V PWM/PFM Auto Mode
1.836
Vout[V]
1.818
1.8
VIN=3.6V
VIN=2.7V
1.782
VIN=4.2V
1.764
0.1
1
10
100
1000
Load Current[mA]
Fig.34 Load regulation
PWM/PFM Auto mode
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© 2011 ROHM Co., Ltd. All rights reserved.
8/14
Target spec. ver.1.7
BU90002GWZ, BU90003GWZ, BU90004GWZ, BU90005GWZ, BU90006GWZ
Technical Note
●Block diagram /Application circuit
L : PWM/PFM MODE
H : PWM MODE
MODE
B1
TSD
UVLO
FB
VIN
A1
PWM/PFM
control
2.3~5.5V
B3
VOUT
EN
+
ERROR COMP
Switching
Control Logic
and
Gate Driver
1.5~0.47uH
B2
VOUT
4.7uF
LX
VREF
EN
H : ON
L : OFF
A2
SHUTDOWN
Frequency
control
A3
GND
●External dimensions
●Pin layout (BOTTOM VIEW)
B1
MODE
B2
LX
B3
FB
A1
VIN
A2
EN
A3
GND
●Pin number/Name/Functions
Pin No.
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Name
Function
A1
VIN
Power supply input pin
A2
EN
Enable pin
A3
GND
B1
MODE
Forced PWM mode pin
GND pin
B2
LX
Inductor connection pin
B3
FB
Feedback voltage input pin
Target spec. ver.1.7
BU90002GWZ, BU90003GWZ, BU90004GWZ, BU90005GWZ, BU90006GWZ
Technical Note
●Functional descriptions
The BU9000XGWZ are a synchronous step-down DC/DC converter that achieves fast transient response from light load to
heavy load by hysteretic PWM control system and current constant PFM control system.
○PWM control
BU9000XGWZ operates by hysteretic PWM control. This scheme ensures fast switching, high efficiency, and fast transient
response.
When the output voltage is below the VREF voltage, the error comparator output is low to high and turning on P-channel
MOSFET until above the VREF voltage and minimum on time.
○PFM control
At light load the regulator and MODE=low, the regulator operates with reduced switching frequency and improves the efficiency.
During PFM operation, the output voltage slightly higher than typical output voltage.
output PWM mode voltage
PFM (constant current)Threshold. turn off Pch FET
PFM Threshold. turn on PFET
PFM Mode at Light Load
PWM Mode at Moderate to Heavy Loads
Fig. Operation of PFM mode and PWM mode
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10/14
Target spec. ver.1.7
BU90002GWZ, BU90003GWZ, BU90004GWZ, BU90005GWZ, BU90006GWZ
Technical Note
●Description of operations
1) Shutdown
If the EN input pin set to low (<0.4V), all circuit are shut down and the regulator is standby mode.
Do not leave the EN pin floating.
2) Soft start function
The regulator has a soft start circuit that reduces in-rush current at start-up. Typical start up times with a 4.7uF output capacitor
is 120usec.
3) Current limit
The BU9000XGWZ has a current limit circuit that protects itself and external components during overload condition.
4) UVLO
The BU9000XGWZ has a Under Voltage Lock Out circuit that turn off device when VIN>2.05V(typ.)
5) FORCED PWM MODE
Setting MODE pin high (>1.4V) places the regulator in forced PWM.
6) TSD
The BU9000XGWZ has a thermal shutdown feature to protect the device if the junction temperature exceeds 150℃.In thermal
shutdown, the DRIVER is disabled.
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11/14
Target spec. ver.1.7
BU90002GWZ, BU90003GWZ, BU90004GWZ, BU90005GWZ, BU90006GWZ
Technical Note
●PC Board layout
The suggested PCB layout for the BU9000XGWZ are shown in Figure. The following guidelines should be used to ensure a
proper layout.
1) The input capacitor CIN should be connect as closely possible to VIN pin and GND pin.
2) From the output voltage to the FB pin line should be as separate as possible.
3) COUT and L should be connected as closely as possible. The connection of L to the LX pin should be as short as possible.
Fig. PCB layout
●External parts selection
1) Inductor selection
The inductance significantly depends on output ripple current. As shown by following equation, the ripple current decreases as
the inductor and/or switching frequency increase.
⊿IL=
(VIN-VOUT)×VOUT
L×VIN×f
f: switching frequency
L: inductance
⊿IL: inductor current ripple
As a minimum requirement, the DC current rating of the inductor should be equal to the maximum load current plus half of the
inductor current ripple as shown by the following equation.
ILPEAK= IOUTMAX +
⊿IL
2
Recommended inductor selection
LQM21MPN1R0NG0 (2.0mm×1.6mm×1.0mm Murata) Iout≦1A
LQM21PN1R0NGC (2.0mm×1.2mm×1.0mm Murata)
Iout≦0.6A
2)Recommended input capacitor(CIN) selection
GRM155R60J225M(1.0mm×0.5mm×0.5mm Murata)
GRM188R60J475ME84(1.6mm×0.8mm×0.8mm Murtata)
3)Recommended output capacitor(COUT) selection
GRM155R60J475M(1.0mm×0.5mm×0.5mm Murata)
GRM155R60G106ME44(1.0mm×0.5mm×0.5mm Murata)
GRM188R60J475ME84(1.6mm×0.8mm×0.8mm Murtata)
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12/14
Target spec. ver.1.7
BU90002GWZ, BU90003GWZ, BU90004GWZ, BU90005GWZ, BU90006GWZ
Technical Note
●Caution of use
1) Absolute maximum ratings
An excess in the absolute maximum rating, such as supply voltage, temperature range of operating conditions, etc.,
can break down the devices, thus making impossible to identify breaking mode, such as a short circuit or an open
circuit. If any over rated values will expect to exceed the absolute maximum ratings, consider adding circuit protection
devices, such as fuses.
2) GND voltage
The potential of GND pin must be minimum potential in all condition. As an exception, the circuit design allows voltages
up to -0.3 V to be applied to the IC pin.
3) Thermal design
Use a thermal design that allows for a sufficient margin in light of the power dissipation (Pd) in actual operating
conditions.
4) Inter-pin shorts and mounting errors
Use caution when positioning the IC for mounting on printed circuit boards. The IC may be damaged if there is any
connection error or if pins are shorted together.
5) Actions in strong electromagnetic field
Use caution when using the IC in the presence of a strong electromagnetic field as doing so may cause the IC to
malfunction.
6) Mutual impedance
Power supply and ground wiring should reflect consideration of the need to lower mutual impedance and minimize
ripple as much as possible (by making wiring as short and thick as possible or rejecting ripple by incorporating
inductance and capacitance).
7) Thermal shutdown Circuit (TSD Circuit)
This model IC has a built-in TSD circuit. This circuit is only to cut off the IC from thermal runaway, and has not been
design to protect or guarantee the IC. Therefore, the user should not plan to activate this circuit with continued
operation in mind.
8) Regarding input pin of the IC
This monolithic IC contains P+ isolation and P substrate layers between adjacent elements in order to keep them
isolated.
P-N junctions are formed at the intersection of these P layers with the N layers of other elements, creating a parasitic
diode or transistor. For example, as shown in the figures below, the relation between each potential is as follows:
When GND > Pin A and GND > Pin B, the P-N junction operates as a parasitic diode.
When GND > Pin B, the P-N junction operates as a parasitic transistor.
Parasitic diodes can occur inevitable in the structure of the IC. The operation of parasitic diodes can result in mutual
interference among circuits, operational faults, or physical damage. Accordingly, methods by which parasitic diodes
operate, such as applying a voltage that is lower than the GND (P substrate) voltage to an input pin, should not be
used.
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13/14
Target spec. ver.1.7
BU90002GWZ, BU90003GWZ, BU90004GWZ, BU90005GWZ, BU90006GWZ
Technical Note
●Ordering part number
TBD
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14/14
Target spec. ver.1.7
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