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25-RT9018A-12GQW

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RT9018A/B
Maximum 3A, Ultra Low Dropout Regulator
General Description
Features
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 1.4V 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
Ordering Information
RT9018A/BPackage Type
SP : SOP-8 (Exposed Pad-Option 1)
QW : WDFN-10L 3x3
Operating Temperature Range
P : Pb Free with Commercial Standard
G : Green (Halogen Free with Commercial Standard)
Z : ECO (Ecological Element)
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
Typically 220mV Dropout at 3A
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
z
Applications
Front Side Bus VTT (1.2V/3A)
z NoteBook PC Applications
z Motherboard Applications
z
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.
Pin Configurations
(TOP VIEW)
8
PGOOD
EN
2
VIN
3
VDD
4
GND
7
ADJ
GND
6
9
5
VOUT
NC
SOP-8 (Exposed Pad)
VOUT 1
VOUT 2
VOUT 3
ADJ 4
PGOOD 5
GND
11
10
9
8
7
9
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.
Maximum 3A Low-Dropout Voltage Regulator
z High Accuracy Output Voltage ± 1.5%
VDD
VIN
VIN
VIN
EN
WDFN-10L 3x3
Enable Pin Function
A : Internal Pull High
B : Internal Pull Low
Note :
Richtek 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.
DS9018A/B-07 September 2010
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1
RT9018A/B
Pin Description
Pin No.
Pin Name
Pin Function
PSOP-8
WDFN 3x3
3
7, 8, 9
VIN
Supply Input Voltage.
2
6
EN
Chip Enable (Active-High).
4
10
VDD
Supply Voltage of Control Circuitry.
1
5
PGOOD Power Good Open Drain Output.
7
4
ADJ
Set the output voltage by the internal feedback resistors when
ADJ is grounded. If external feedback resistors is used, VOUT =
0.8V x (R1 + R2)/R2.
6
1, 2, 3
VOUT
Output Voltage.
5
--
NC
No Internal Connection.
8,
Exposed Pad (11) GND
Exposed Pad (9)
Ground. The exposed pad must be soldered to a large PCB and
connected to GND for maximum power dissipation.
Typical Application Circuit
VOUT = 0.8 × R1 + R2
R2
VIN
10µF
Chip Enable
VOUT
VOUT
RT9018
VDD
VDD
10µF
10µF
Chip Enable
ADJ
EN
VIN
VIN
PGOOD
GND
R1
10µF
ADJ
EN
R2
PGOOD
VDD
GND
100k
1µF
CDummy
RT9018A/B
VDD
VOUT
VOUT
100k
1µF
VOUT
VOUT
Figure 1. Fixed Voltage Regulator
Figure 2. Adjustable Voltage Regulator
Function Block Diagram
VOUT
VIN
OCP
Driver
Error
Amplifier
EN
VDD
-
+
OTP
POR
Mode
0.8V
ADJ
PGOOD
0.72V
+
GND
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DS9018A/B-07 September 2010
RT9018A/B
Absolute Maximum Ratings
(Note 1)
Supply Voltage, VIN ------------------------------------------------------------------------------------------------- 1V to 6V
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 2)
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 3)
HBM (Human Body Mode) ----------------------------------------------------------------------------------------- 2kV
MM (Machine Mode) ------------------------------------------------------------------------------------------------ 200V
z
z
Recommended Operating Conditions
(Note 4)
Supply Voltage, VIN ------------------------------------------------------------------------------------------------- 1.4V to 5.5V
Control Voltage, VDD (VDD P VOUT + 1.5V) --------------------------------------------------------------------- 3V to 5.5V
z Junction Temperature Range -------------------------------------------------------------------------------------- −40°C to 125°C
z Ambient Temperature Range -------------------------------------------------------------------------------------- −40°C to 85°C
z
z
Electrical Characteristics
(VIN = VOUT + 500mV, VEN = VDD = 5V, CIN = COUT = 10μF, TA = TJ = 25°C, unless otherwise specified)
Parameter
Min
Typ
Max
Unit
POR Threshold
2.4
2.7
3
V
POR Hysteresis
0.15
0.2
--
V
IOUT = 1mA
--
0.2
0.4
V
IOUT = 1mA
0.788
0.8
0.812
V
−1.5
0
+1.5
%
--
0.2
0.6
%
--
0.2
1
%
IOUT = 2A
--
150
250
mV
IOUT = 3A
--
210
350
mV
VDD = 5.5V
--
0.6
1.2
mA
3.2
4.5
--
A
Adjustable Pin Threshold
Symbol
VTH_ADJ
Reference Voltage (ADJ Pin Voltage) VADJ
Fixed Output Voltage Range
ΔVOUT
Line Regulation (VIN)
ΔVLINE_IN
Load Regulation
ΔVLOAD
(Note 7)
Dropout Voltage (Note 5)
VDROP
Quiescent Current (Note 6)
IQ
Current Limit
ILIM
Test Conditions
VIN = VOUT + 0.5V to 5V,
IOUT = 1mA
VIN = VOUT + 1V,
IOUT = 1mA to 3A
Short Circuit Current
VOUT < 0.2V
0.5
1.8
--
A
In-rush Current
COUT = 10μF, Enable Start-up
--
0.6
--
A
VOUT Pull Low Resistance
VEN = 0V
--
150
--
Ω
To be continued
DS9018A/B-07 September 2010
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3
RT9018A/B
Parameter
Symbol
Test Conditions
Min
Typ
Max
Unit
---
12
10
-20
μA
---
1
0.2
Chip Enable
EN Input Bias Current
VDD Shutdown RT9018A
Current
RT9018B
I EN
VEN = 0V
I SHDN
VEN = 0V
Logic-Low Voltage VENL
Logic-High Voltage VENH
VDD = 5V
---
VDD = 5V
1.2
--
--
Power Good
PGOOD Rising Threshold
--
90
93
%
PGOOD Hysteresis
3
10
--
%
--
0.2
0.4
V
0.5
1.5
5
ms
EN Threshold
PGOOD Sink Capability
IPGOOD = 10mA
PGOOD Delay
Thermal Protection
μA
V
Thermal Shutdown Temperature
TSD
--
160
--
°C
Thermal Shutdown Hysteresis
ΔTSD
--
30
--
°C
--
110
--
°C
Thermal Shutdown Temperature
Fold-back
VOUT < 0.4V
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. 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 3. Devices are ESD sensitive. Handling precaution recommended.
Note 4. The device is not guaranteed to function outside its operating conditions.
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-07 September 2010
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
VIN
3
VDD = 5V, VOUT = 1.2V, IOUT = 2A
VIN
2
3
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
VDD
5
VIN = 1.8V, VOUT = 1.2V, IOUT = 2A
VDD
4
5
4
VOUT
(20mV/Div)
VOUT
(20mV/Div)
Time (250μs/Div)
DS9018A/B-07 September 2010
Time (250μs/Div)
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5
RT9018A/B
Dropout Voltage vs. Load Current
Start Up from Enable
400
IOUT = 3A
Dropout Voltage (mV)
350
125°C
300
250
EN
(1V/Div)
25°C
VOUT
(1V/Div)
200
150
PGOOD
(1V/Div)
-40°C
100
I IN
(2A/Div)
50
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
VIN
(1V/Div)
VDD
(5V/Div)
VOUT
(1V/Div)
VOUT
(1V/Div)
PGOOD
(1V/Div)
PGOOD
(1V/Div)
I IN
(2A/Div)
I IN
(2A/Div)
Time (500μs/Div)
Time (1ms/Div)
Short Circuit Current vs. Temperature
Short Circuit Protection
IOUT
(1A/Div)
Short Circuit Current Ishort (A)
VDD = 5V, VIN = 1.8V, VOUT = 1.2V
2.6
2.4
2.2
2.0
1.8
1.6
1.4
1.2
1.0
Time (100μs/Div)
-40
-20
0
20
40
60
80
100
Temperature (°C)
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DS9018A/B-07 September 2010
RT9018A/B
28
VDD Standby Current vs. Temperature
Quiescent Current vs. Temperature
1200
1.2
VIN = 3.3V, VEN = 0V, VDD = 5V
24
20
16
RT9018A
12
8
4
VIN = 1.8V, VOUT = 1.2V, IOUT = 0A
1100
1.1
QuiescentCurrent
Current(mA)
(uA)
Quiescent
VDD Standby Current (μA)1
32
RT9018B
0
1000
1.0
900
0.9
800
0.8
700
0.7
600
0.6
500
0.5
400
0.4
300
0.3
200
0.2
100
0.1
0
-4
-50
-25
0
25
50
75
100
-40 -25 -10
125
5
50
65
80
95 110 125
Output Voltage vs. Temperature
Reference Voltage vs. Temperature
1.25
0.84
1.24
0.83
VIN = 1.8V, VADJ = 0V, IOUT = 0A
1.23
0.82
Output Voltage (V)
Reference Voltage (V)
35
Temperature (°C)
Temperature (°C)
0.81
0.80
0.79
0.78
1.22
1.21
1.20
1.19
1.18
1.17
0.77
1.16
0.76
1.15
-40 -25 -10
5
20
35
50
65
80
95 110 125
-40 -25 -10
5
Temperature (°C)
ADJ Threshold Voltage Range (V)
2.95
2.90
Rising
2.80
2.75
2.70
2.65
Falling
2.60
35
50
65
80
95 110 125
ADJ Threshold Voltage vs. Temperature
VDD POR Threshold Voltage vs. Temperature
2.85
20
Temperature (°C)
3.00
POR Voltage (V)
20
2.55
2.50
2.45
2.40
0.30
0.28
0.26
0.24
0.22
0.20
0.18
0.16
0.14
0.12
0.10
-40 -25 -10
5
20
35
50
65
Temperature (°C)
DS9018A/B-07 September 2010
80
95 110 125
-40 -25 -10
5
20
35
50
65
80
95 110 125
Temperature (°C)
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7
RT9018A/B
Over Current Protection Fold Back
Output Voltage VOUT (V)
3
VIN = VEN = 3.3V, VDD = 5V
2.5
2
1.5
1
0.5
0
0
0.5
1
1.5
2
2.5
3
3.5
4
Loading Current I OUT (A)
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DS9018A/B-07 September 2010
RT9018A/B
Application Information
Adjustable Mode Operation
Power Good
The output voltage of RT9018A/B is adjustable from 0.8V
to (VIN - VDROP) by external voltage divider resisters as
shown in Typical Application Circuit (Figure 2). The value
of resisters R1 and R2 should be more than 10kΩ to
reduce the power loss. The VDD must be greater than
(VOUT + 1.5V).
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.
Thermal-Shutdown Protection
Enable
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 10μA 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.
Output Capacitor
The RT9018A/B is specifically designed to employ ceramic
output capacitors as low as 10μF. The ceramic capacitors
offer significant cost and space savings, along with high
frequency noise filtering.
Input Capacitor
Good bypassing is recommended from input to ground to
help improve AC performance. A 10μF input capacitor or
greater located as close as possible to the IC is
recommended.
Current Limit
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.
DS9018A/B-07 September 2010
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
For continuous operation, do not exceed absolute
maximum operation junction temperature 125°C. The
power dissipation definition in device is:
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:
PD(MAX) = ( TJ(MAX) − TA ) / θJA
Where T J(MAX) is the maximum operation junction
temperature 125°C, TA is the ambient temperature and the
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
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9
RT9018A/B
following formula:
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.
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
θJA to 49°C/W.
Figure 3 (d). Copper Area = 50mm2, θJA = 51°C/W
Figure 3 (e). Copper Area = 70mm2, θJA = 49°C/W
Figure 3. Thermal Resistance vs. Different Cooper Area
Layout Design
The maximum power dissipation depends on operating
ambient temperature for fixed T J(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
Figure 3 (b). Copper Area = 10mm2, θJA = 64°C/W
Power Dissipation (W)
2
70mm2
1.8
50mm2
1.6
30mm2
1.4
10mm2
Minimum Layout
1.2
1
0.8
0.6
0.4
0.2
0
JEDEC 4-Layers PCB
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-07 September 2010
RT9018A/B
Outline Dimension
H
A
M
EXPOSED THERMAL PAD
(Bottom of Package)
Y
J
X
B
F
C
I
D
Dimensions In Millimeters
Symbol
Dimensions In Inches
Min
Max
Min
Max
A
4.801
5.004
0.189
0.197
B
3.810
4.000
0.150
0.157
C
1.346
1.753
0.053
0.069
D
0.330
0.510
0.013
0.020
F
1.194
1.346
0.047
0.053
H
0.170
0.254
0.007
0.010
I
0.000
0.152
0.000
0.006
J
5.791
6.200
0.228
0.244
M
0.406
1.270
0.016
0.050
X
2.000
2.300
0.079
0.091
Y
2.000
2.300
0.079
0.091
X
2.100
2.500
0.083
0.098
Y
3.000
3.500
0.118
0.138
Option 1
Option 2
8-Lead SOP (Exposed Pad) Plastic Package
DS9018A/B-07 September 2010
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11
RT9018A/B
D2
D
L
E
E2
1
SEE DETAIL A
2
e
2
1
b
DETAIL A
Pin #1 ID and Tie Bar Mark Options
A
A1
1
A3
Note : The configuration of the Pin #1 identifier is optional,
but must be located within the zone indicated.
Symbol
Dimensions In Millimeters
Dimensions In Inches
Min
Max
Min
Max
A
0.700
0.800
0.028
0.031
A1
0.000
0.050
0.000
0.002
A3
0.175
0.250
0.007
0.010
b
0.180
0.300
0.007
0.012
D
2.950
3.050
0.116
0.120
D2
2.300
2.650
0.091
0.104
E
2.950
3.050
0.116
0.120
E2
1.500
1.750
0.059
0.069
e
L
0.500
0.350
0.020
0.450
0.014
0.018
W-Type 10L DFN 3x3 Package
Richtek Technology Corporation
Richtek Technology Corporation
Headquarter
Taipei Office (Marketing)
5F, No. 20, Taiyuen Street, Chupei City
8F, No. 137, Lane 235, Paochiao Road, Hsintien City
Hsinchu, Taiwan, R.O.C.
Taipei County, Taiwan, R.O.C.
Tel: (8863)5526789 Fax: (8863)5526611
Tel: (8862)89191466 Fax: (8862)89191465
Email: marketing@richtek.com
Information that is provided by Richtek Technology Corporation is believed to be accurate and reliable. Richtek reserves the right to make any change in circuit
design, specification or other related things if necessary without notice at any time. No third party intellectual property infringement of the applications should be
guaranteed by users when integrating Richtek products into any application. No legal responsibility for any said applications is assumed by Richtek.
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DS9018A/B-07 September 2010
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