RT9018B25PSP [RICHTEK]
Maximum 3A, Ultra Low Dropout Regulator; 最大3A ，超低压差稳压器
| 型号： | RT9018B25PSP |
| 厂家： | 
RICHTEK TECHNOLOGY CORPORATION |
| 描述： | Maximum 3A, Ultra Low Dropout Regulator |
| 文件： | 总12页 (文件大小：143K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
RT9018A/B
Maximum 3A, Ultra Low Dropout Regulator
General Description
Features
z Maximum 3A Low-Dropout Voltage Regulator
z High Accuracy Output Voltage 1.5%
z Typically 220mV Dropout at 3A
The RT9018A/B is a high performance positive voltage
regulator designed for use in applications requiring very
low Input voltage and very low dropout voltage at up to
3A(Peak). It operates with a VIN as low as 1.0V and VDD
voltage 3V with output voltage programmable as low as
0.8V. The significant feature includes ultra low dropout,
ideal for applications where VOUT is very close to VIN.
Additionally, there is an enable pin to further reduce power
dissipation while shutdown. The RT9018A/B provides
excellent regulation over variations in line, load and
temperature. and provides a power OK signal to indicate
if the voltage level of Vo reaches 90% of its rating value.
z Power Good Output
z Output Voltage Pull Low Resistance when Disable
z Thermal and Over Current Protection
z RoHS Compliant and 100% Lead (Pb)-Free
Applications
z Front Side Bus VTT (1.2V/3A)
z NoteBook PC Applications
z MotherboardApplications
The RT9018A/B is available in the SOP-8 (Exposed Pad)
and WDFN-10L 3x3 packages with 1V, 1.05V, 1.2V, 1.5V,
1.8V and 2.5V internally preset outputs that are also
adjustable using external resistors.
Marking Information
For marking information, contact our sales representative
directly or through a Richtek distributor located in your
area, otherwise visit our website for detail.
Ordering Information
RT9018A/B
Pin Configurations
Package Type
SP : SOP-8 (Exposed Pad-Option 1)
QW : WDFN-10L 3x3
(TOP VIEW)
8
7
6
5
PGOOD
EN
GND
ADJ
2
3
4
Operating Temperature Range
P : Pb Free with Commercial Standard
G : Green (Halogen Free with Commer-
cial Standard)
GND
VIN
VOUT
NC
9
VDD
SOP-8 (Exposed Pad)
Output Voltage
10 : 1V/Adj
1K : 1.05V/Adj
12 : 1.2V/Adj
15 : 1.5V/Adj
18 : 1.8V/Adj
25 : 2.5V/Adj
VOUT
1
2
3
4
5
10 VDD
9
VIN
VOUT
VOUT
ADJ
GND
11
8
VIN
VIN
7
9
PGOOD
EN
WDFN-10L 3x3
Enable Pin Function
A : Internal Pull High
B : Internal Pull Low
Note :
Richtek Pb-free and Green products are :
`RoHS compliant and compatible with the current require-
ments of IPC/JEDEC J-STD-020.
`Suitable for use in SnPb or Pb-free soldering processes.
`100% matte tin (Sn) plating.
DS9018A/B-04 September 2007
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1
RT9018A/B
Pin Description
Pin No.
Pin Name
Pin Function
PSOP-8
WDFN 3x3
3
2
4
1
7, 8, 9
VIN
EN
Supply Input Voltage.
6
10
5
Chip Enable (Active-High).
VDD
Supply Voltage of Control Circuitry.
PGOOD Power Good Open Drain Output.
Set the output voltage by the internal feedback resistors when
7
4
ADJ
ADJ is grounded. If external feedback resistors is used, V
=
OUT
0.8V x (R1 + R2)/R2.
6
5
1, 2, 3
--
VOUT
NC
Output Voltage.
No Internal Connection.
8,
Ground. The exposed pad must be soldered to a large PCB and
connected to GND for maximum power dissipation.
Exposed Pad (11) GND
Exposed Pad (9)
Typical Application Circuit
R1+ R2
V
OUT
= 0.8×
R2
VIN
VIN
V
V
V
V
VOUT
VOUT
IN
OUT
OUT
IN
C
Dummy
R1
R2
10uF
10uF
RT9018A/B
RT9018A/B
10uF
10uF
Chip Enable
Chip Enable
ADJ
EN
ADJ
EN
PGOOD
PGOOD
V
V
DD
VDD
VDD
DD
GND
GND
100k
100k
1uF
1uF
V
V
OUT
OUT
Figure 1. Fixed Voltage Regulator
Figure 2. Adjustable Voltage Regulator
Function Block Diagram
VOUT
VIN
OCP
Driver
Error
Amplifier
OTP
POR
EN
VDD
Mode
ADJ
0.8V
PGOOD
-
+
0.72V
GND
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DS9018A/B-04 September 2007
RT9018A/B
Absolute Maximum Ratings (Note 1)
z Supply Voltage, VIN --------------------------------------------------------------------------------------------------- 1V to 6V
z Control Voltage, VDD -------------------------------------------------------------------------------------------------- 3V to 6V
z Output Voltage, VOUT ------------------------------------------------------------------------------------------------- 0.8 to 6V
z Power Dissipation, PD @ TA = 25°C
SOP-8 (Exposed Pad) ----------------------------------------------------------------------------------------------- 1.33W
WDFN-10L 3x3 --------------------------------------------------------------------------------------------------------- 1.67W
z Package Thermal Resistance (Note 4)
SOP-8 (Exposed Pad), θJA ------------------------------------------------------------------------------------------ 75°C/W
SOP-8 (Exposed Pad), θJC ----------------------------------------------------------------------------------------- 15°C/W
WDFN-10L 3x3, θJA --------------------------------------------------------------------------------------------------- 60°C/W
z Junction Temperature ------------------------------------------------------------------------------------------------- 150°C
z Lead Temperature (Soldering, 10 sec.)--------------------------------------------------------------------------- 260°C
z Storage Temperature Range ---------------------------------------------------------------------------------------- −65°C to 150°C
z ESD Susceptibility (Note 2)
HBM (Human Body Mode) ------------------------------------------------------------------------------------------ 2kV
MM (Machine Mode) -------------------------------------------------------------------------------------------------- 200V
Recommended Operating Conditions (Note 3)
z Supply Voltage, VIN --------------------------------------------------------------------------------------------------- 1.4V to 5.5V
z Control Voltage, VDD -------------------------------------------------------------------------------------------------- 3.6V to 5.5V
z Junction Temperature Range---------------------------------------------------------------------------------------- −40°C to 125°C
z Ambient Temperature Range---------------------------------------------------------------------------------------- −40°C to 85°C
Electrical Characteristics
(VIN = VOUT + 500mV, VEN = VDD = 5V, CIN = COUT = 10uF, TA = TJ = 25°C, unless otherwise specified)
Parameter
VDD Operation Voltage Range
POR Threshold
Symbol
Test Conditions
Min
3.6
Typ
--
Max Units
V
V
Input Range
5.5
3
V
V
V
V
V
%
DD
DD
2.4
2.7
0.2
0.2
0.8
0
POR Hysteresis
0.15
--
--
Adjustable Pin Threshold
V
I
I
= 1mA
= 1mA
0.4
0.812
+1.5
TH_ADJ
ADJ
OUT
Reference Voltage (ADJ Pin Voltage) V
0.788
−1.5
OUT
Fixed Output Voltage Range
ΔV
OUT
V
= V
= 1mA
+ 0.5V to 5V,
+ 1V,
IN
OUT
Line Regulation (V )
ΔV
--
0.2
0.2
0.6
1
%
%
IN
LINE_IN
I
OUT
V
IN
= V
OUT
= 1mA to 3A
Load Regulation
(Note 7)
ΔV
--
LOAD
I
I
I
OUT
= 2A
--
--
--
150
210
0.6
250
350
1.2
mV
mV
mA
OUT
OUT
Dropout Voltage (Note 5)
V
DROP
= 3A
Quiescent Current (Note 6)
Current Limit
I
I
V
DD
= 5.5V
Q
3.2
0.5
--
4.5
1.8
0.6
150
--
--
--
--
A
A
A
Ω
LIM
Short Circuit Current
In-rush Current
V
OUT
< 0.2V
C
V
= 10uF, Enable Start-up
OUT
V
OUT
Pull Low Resistance
= 0V
--
EN
To be continued
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3
RT9018A/B
Parameter
Chip Enable
Symbol
Test Conditions
Min
Typ
Max
Units
EN Input Bias Current
I
I
V
V
= 0V
--
--
12
10
--
--
20
1
μA
μA
EN
EN
RT9018A
VDD Shutdown
Current
= 0V
SHDN
EN
RT9018B
--
Logic-Low Voltage V
V
V
= 5V
= 5V
--
--
0.2
--
ENL
ENH
DD
EN Threshold
V
Logic-High Voltage V
1.2
--
DD
Power Good
PGOOD Rising Threshold
PGOOD Hysteresis
PGOOD Sink Capability
PGOOD Delay
--
3
90
10
93
--
%
%
I
= 10mA
--
0.2
1.5
0.4
5
V
PGOOD
0.5
ms
Thermal Protection
Thermal Shutdown Temperature
Thermal Shutdown Hysteresis
Thermal Shutdown Temperature
Fold-back
T
--
--
160
30
--
--
°C
°C
SD
ΔT
SD
V
OUT
< 0.4V
--
110
--
°C
Note 1. Stresses listed as the above "Absolute Maximum Ratings" may cause permanent damage to the device. These are for
stress ratings. Functional operation of the device at these or any other conditions beyond those indicated in the
operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended
periods may remain possibility to affect device reliability.
Note 2. Devices are ESD sensitive. Handling precaution recommended.
Note 3. The device is not guaranteed to function outside its operating conditions.
Note 4. θJA is measured in the natural convection at TA = 25°C on a high effective thermal conductivity test board (4 Layers,
2S2P) of JEDEC 51-7 thermal measurement standard. The case point of θJC is on the expose pad for SOP-8 (Exposed
Pad) package.
Note 5. The dropout voltage is defined as VIN -VOUT, which is measured when VOUT is VOUT(NORMAL) - 100mV.
Note 6. Quiescent, or ground current, is the difference between input and output currents. It is defined by IQ = IIN - IOUT under no
load condition (IOUT = 0mA). The total current drawn from the supply is the sum of the load current plus the ground pin
current.
Note 7. Regulation is measured at constant junction temperature by using a 2ms current pulse. Devices are tested for load
regulation in the load range from 1mA to 3A.
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DS9018A/B-04 September 2007
RT9018A/B
Typical Operating Characteristics
Load Transient Response
Load Transient Response
VDD = 5V, VIN = 1.8V, VOUT = 1.2V
VDD = 5V, VIN = 1.8V, VOUT = 1.2V
VOUT
(20mV/Div)
VOUT
(20mV/Div)
IOUT
(1A/Div)
IOUT
(1A/Div)
Time (2.5ms/Div)
Time (2.5ms/Div)
VIN Line Transient Response
VIN Line Transient Response
VDD = 5V, VOUT = 1.2V, IOUT = 0A
VDD = 5V, VOUT = 1.2V, IOUT = 2A
3
3
2
VIN
VIN
2
VOUT
(20mV/Div)
VOUT
(20mV/Div)
Time (250μs/Div)
Time (250μs/Div)
VDD Line Transient Response
VDD Line Transient Response
VIN = 1.8V, VOUT = 1.2V, IOUT = 0A
VIN = 1.8V, VOUT = 1.2V, IOUT = 2A
5
5
VDD
VDD
4
4
VOUT
(20mV/Div)
VOUT
(20mV/Div)
Time (250μs/Div)
Time (250μs/Div)
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RT9018A/B
Dropout Voltage vs. Load Current
Start Up from Enable
400
350
300
250
200
150
100
50
IOUT = 3A
125°C
25°C
EN
(1V/Div)
VOUT
(1V/Div)
PGOOD
(1V/Div)
-40°C
IIN
(2A/Div)
0
0
0.3 0.6 0.9 1.2 1.5 1.8 2.1 2.4 2.7
3
Time (500μs/Div)
Load Current (A)
Start Up from VDD
Start Up from VIN
IOUT = 3A
IOUT = 3A
VDD
(5V/Div)
VIN
(1V/Div)
VOUT
(1V/Div)
VOUT
(1V/Div)
PGOOD
(1V/Div)
PGOOD
(1V/Div)
IIN
(2A/Div)
IIN
(2A/Div)
Time (500μs/Div)
Time (1ms/Div)
Short Circuit Current vs. Temperature
Short Circuit Protection
2.6
VDD = 5V, VIN = 1.8V, VOUT = 1.2V
2.4
2.2
2.0
1.8
1.6
1.4
1.2
1.0
IOUT
(1A/Div)
-40
-20
0
20
40
60
80
100
Time (100μs/Div)
Temperature
(°C)
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DS9018A/B-04 September 2007
RT9018A/B
VDD Standby Current vs. Temperature
Quiescent Current vs. Temperature
1.2
32
28
24
20
16
12
8
VIN = 3.3V, VEN = 0V, VDD = 5V
VIN = 1.8V, VOUT = 1.2V, IOUT = 0A
1.1
1.0
0.9
0.8
0.7
RT9018A
RT9018B
0.6
0.5
0.4
0.3
4
0.2
0
0.1
-4
0
-50
-25
0
25
50
75
100
125
-40 -25 -10
5
20 35 50 65 80 95 110 125
(°C)
Temperature
Temperature (°C)
Reference Voltage vs. Temperature
Output Voltage vs. Temperature
0.84
1.25
VIN = 1.8V, VADJ = 0V, IOUT = 0A
1.24
1.23
1.22
1.21
1.20
1.19
1.18
1.17
1.16
1.15
0.83
0.82
0.81
0.80
0.79
0.78
0.77
0.76
-40 -25 -10
5
20 35 50 65 80 95 110 125
-40 -25 -10
5
20 35 50 65 80 95 110 125
Temperature (°C)
Temperature
(°C)
VDD POR Threshold Voltage vs. Temperature
ADJ Threshold Voltage vs. Temperature
3.00
0.30
0.28
0.26
0.24
0.22
0.20
0.18
0.16
0.14
0.12
0.10
2.95
2.90
2.85
2.80
2.75
2.70
2.65
2.60
2.55
2.50
2.45
2.40
Rising
Falling
-40 -25 -10
5
20 35 50 65 80 95 110 125
-40 -25 -10
5
20 35 50 65 80 95 110 125
Temperature (°C)
Temperature
(°C)
DS9018A/B-04 September 2007
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7
RT9018A/B
Over Current Protection Fold Back
3
2.5
2
VIN = VEN = 3.3V, VDD = 5V
1.5
1
0.5
0
0
0.5
1
1.5
2
2.5
3
3.5
4
Loading Current IOUT (A)
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DS9018A/B-04 September 2007
RT9018A/B
Application Information
Adjustable Mode Operation
Power Good
The output voltage of RT9018A/B is adjustable from 0.8V
to VIN by external voltage divider resisters as shown in
TypicalApplication Circuit (Figure 2). The value of resisters
R1 and R2 should be more than 10kΩ to reduce the power
loss.
The power good function is an open-drain output. Connects
100kΩ pull up resistor to VOUT to obtain an output voltage.
The PGOOD pin will output high immediately after the
output voltage arrives 90% of normal output voltage. The
PGOOD pin will output high with typical 1.5ms delay time.
Enable
Thermal-Shutdown Protection
The RT9018A/B goes into shutdown mode when the EN
pin is in the logic low condition. During this condition, the
pass transistor, error amplifier, and band gap are turned
off, reducing the supply current to 10uA typical. The
RT9018A/B goes into operation mode when the EN pin is
in the logic high condition. If the EN pin is floating, NOTE
that the RT9018A/B internal initial logic level. For RT9018A,
the EN pin function pulls high level internally. So the
regulator will be turn on when EN pin is floating. For
RT9018B, the EN pin function pulls low level internally.
So the regulator will be turn off when EN pin is floating.
Thermal protection limits power dissipation to prevent IC
over temperature in RT9018A/B. When the operation
junction temperature exceeds 160°C, the over-temperature
protection circuit starts the thermal shutdown function
and turns the pass transistor off. The pass transistor turn
on again after the junction temperature cools by 30°C.
RT9018A/B lowers its OTP trip level from 160°C to 110°C
when output short circuit occurs (VOUT < 0.4V). It limits
IC case temperature under 100°C and provides maximum
safety to customer while output short circuit occurring.
Power Dissipation
Output Capacitor
For continuous operation, do not exceed absolute
maximum operation junction temperature 125°C. The
power dissipation definition in device is:
The RT9018A/B is specifically designed to employ ceramic
output capacitors as low as 10uF. The ceramic capacitors
offer significant cost and space savings, along with high
frequency noise filtering.
PD = (VIN − VOUT) x IOUT + VIN x IQ
The maximum power dissipation depends on the thermal
resistance of IC package, PCB layout, the rate of
surroundings airflow and temperature difference between
junctions to ambient. The maximum power dissipation can
be calculated by following formula:
Input Capacitor
Good bypassing is recommended from input to ground to
help improve AC performance. A 10uF input capacitor or
greater located as close as possible to the IC is
recommended.
PD(MAX) = ( TJ(MAX) − TA ) / θJA
Where TJ(MAX) is the maximum operation junction
Current Limit
temperature 125°C, TAis the ambient temperature and the
The RT9018A/B contains an independent current limit and
the short circuit current protection to prevent unexpected
applications. The current limit monitors and controls the
pass transistor’ s gate voltage, limiting the output current
to higher than 4.5A typical. When the output voltage is
less than 0.4V, the short circuit current protection starts
the current fold back function and maintains the loading
current 1.8A. The output can be shorted to ground
indefinitely without damaging the part.
θJA is the junction to ambient thermal resistance.
For recommended operating conditions specification of
RT9018A/B, where TJ (MAX) is the maximum junction
temperature of the die (125°C) and TA is the maximum
ambient temperature. The junction to ambient thermal
resistance for SOP-8 (Exposed Pad) package is 75°C/W
on the standard JEDEC 51-7 (4 layers, 2S2P) thermal
test board. The copper thickness is 2oz. The maximum
power dissipation at TA = 25°C can be calculated by
following formula:
DS9018A/B-04 September 2007
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9
RT9018A/B
PD (MAX) = (125°C − 25°C) / (75°C/W) = 1.33W (SOP-8
Exposed Pad on the minimum layout)
Layout Considerations
The thermal resistance θJA of SOP-8 (Exposed Pad) is
determined by the package design and the PCB design.
However, the package design had been designed. If
possible, it’ s useful to increase thermal performance by
the PCB design. The thermal resistance θJA can be
decreased by adding a copper under the exposed pad of
SOP-8 (Exposed Pad) package.
Figure 3 (d). Copper Area = 50mm2, θJA = 51°C/W
As shown in Figure 3, the amount of copper area to which
the SOP-8 (Exposed Pad) is mounted affects thermal
performance. When mounted to the standard SOP-8
(Exposed Pad) pad (Figure 3.a), θJA is 75°C/W. Adding
copper area of pad under the SOP-8 (Exposed Pad) Figure
3.b) reduces the θJA to 64°C/W. Even further, increasing
the copper area of pad to 70mm2 (Figure 3.e) reduces the
Figure 3 (e). Copper Area = 70mm2, θJA = 49°C/W
Figure 3. Thermal Resistance vs. Different CooperArea
LayoutDesign
θ
JA to 49°C/W.
The maximum power dissipation depends on operating
ambient temperature for fixed TJ(MAX) and thermal
resistance θJA . For RT9018A/B packages, the Figure 4
of de-rating curves allows the designer to see the effect of
rising ambient temperature on the maximum power
allowed.
Figure 3 (a). Minimum Footprint, θJA = 75°C/W
2.2
Copper Area
2
70mm2
1.8
50mm2
30mm2
10mm2
Minimum Layout
1.6
1.4
1.2
1
0.8
0.6
0.4
Figure 3 (b). Copper Area = 10mm2, θJA = 64°C/W
0.2
JEDEC 4-Layers PCB
0
0
20
40
60
80
100
120
140
Ambient Temperature (°C)
Figure 4.De-rating Curves
Figure 3 (c). Copper Area = 30mm2,θJA = 54°C/W
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DS9018A/B-04 September 2007
RT9018A/B
Outline Dimension
H
A
Y
M
EXPOSED THERMAL PAD
(Bottom of Package)
J
B
X
F
C
I
D
Dimensions In Millimeters Dimensions In Inches
Symbol
Min
Max
Min
Max
0.197
0.157
0.069
0.020
0.053
0.010
0.006
0.244
0.050
0.091
0.091
0.098
0.138
A
B
C
D
F
H
I
4.801
3.810
1.346
0.330
1.194
0.170
0.000
5.791
0.406
2.000
2.000
2.100
3.000
5.004
4.000
1.753
0.510
1.346
0.254
0.152
6.200
1.270
2.300
2.300
2.500
3.500
0.189
0.150
0.053
0.013
0.047
0.007
0.000
0.228
0.016
0.079
0.079
0.083
0.118
J
M
X
Y
X
Y
Option 1
Option 2
8-Lead SOP (Exposed Pad) Plastic Package
DS9018A/B-04 September 2007
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11
RT9018A/B
D2
D
L
E
E2
SEE DETAIL A
1
e
b
2
1
2
1
A
A3
DETAILA
Pin #1 ID and Tie Bar Mark Options
A1
Note : The configuration of the Pin #1 identifier is optional,
but must be located within the zone indicated.
Dimensions In Millimeters
Dimensions In Inches
Symbol
Min
Max
Min
Max
A
A1
A3
b
0.700
0.000
0.175
0.180
2.950
2.300
2.950
1.500
0.800
0.050
0.250
0.300
3.050
2.650
3.050
1.750
0.028
0.000
0.007
0.007
0.116
0.091
0.116
0.059
0.031
0.002
0.010
0.012
0.120
0.104
0.120
0.069
D
D2
E
E2
e
0.500
0.020
L
0.350
0.450
0.014
0.018
W-Type 10L DFN 3x3 Package
Richtek Technology Corporation
Headquarter
Richtek Technology Corporation
Taipei Office (Marketing)
5F, No. 20, Taiyuen Street, Chupei City
Hsinchu, Taiwan, R.O.C.
8F, No. 137, Lane 235, Paochiao Road, Hsintien City
Taipei County, Taiwan, R.O.C.
Tel: (8863)5526789 Fax: (8863)5526611
Tel: (8862)89191466 Fax: (8862)89191465
Email: marketing@richtek.com
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DS9018A/B-04 September 2007
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