Richtek RT9018A-10GQW, RT9018A-12GQW, RT9018A-12PQW, RT9018A-15GQW, RT9018A-18GQW Schematic [ru]

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Maximum 3A, Ultra Low Dropout Regulator

RT9018A/B

General Description

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.

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.

Ordering Information

RT9018A/B-

Package Type SP : SOP-8 (Exposed Pad-Option 1) QW : WDFN-10L 3x3

Lead Plating System P : Pb Free G : Green (Halogen Free and Pb Free) Z : ECO (Ecological Element with Halogen Free and Pb free)

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

Enable Pin Function A : Internal Pull High B : Internal Pull Low

Note :

Richtek 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.

Features

z Maximum 3A Low-Dropout Voltage Regulator

z High Accuracy Output Voltage

z Typically 210mV 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

±±

±1.5%

±±

Applications

z Front Side Bus VTT (1.2V/3A)

z NoteBook PC Applications

z Motherboard Applications

Marking Information

For marking information, contact our sales representative

directly or through a Richtek distributor located in your

area.

Pin Configurations

(TOP VIEW)

GND

ADJ

VOUT

VDD

VIN

PGOOD

VIN

VDD

SOP-8 (Exposed Pad)

VOUT

ADJ

PGOOD

WDFN-10L 3x3

DS9018A/B-09 April 2012 www.richtek.com

RT9018A/B

Typical Application Circuit

10µF

VIN

VDD

1µF

VOUT

RT9018A/B

PGOOD

GND

ADJ

100k

OUT

Chip Enable

Figure 1. Fixed Voltage Regulator Figure 2. Adjustable Voltage Regulator

10µF

OUT

Chip Enable

R2R1

×=

10µF

OUT

0.8 V

OUT

VIN

10µF

VDD

1µF

VOUT

RT9018A/B

PGOOD

GND

ADJ

Dummy

100k

OUT

Function

Pin Description

Pi n No.

SOP-8

(Exposed Pad)

WDFN -1 0L 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

6 1, 2, 3 VOUT Output Voltage.

5 -- NC No Internal Connection.

9 (Exposed Pad)

11 (Exposed Pad) GND

Function Block Diagram

VIN

Pin Name

Pin Function

Set the output voltage by the internal feedback resistors when ADJ is grounded. If external feedback resistors is used, V

OUT

0.8V x (R 1 + R2) /R2.

Ground. The exposed pad must be soldered to a large PCB and connected to GND for maximum power dissipation.

VOUT

OCP

OTP

VDD

POR

Driver

0.8V

0.72V

Error

Amplifier

Mode

ADJ

PGOOD

GND

DS9018A/B-09 April 2012www.richtek.com

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, P

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

@ TA = 25°C

Recommended Operating Conditions (Note 4)

z Supply Voltage, V

z Control Voltage, VDD

z Control Voltage with PGOOD, VDD

z Junction Temperature Range -------------------------------------------------------------------------------------------- −40°C to 125°C z Ambient Temperature Range -------------------------------------------------------------------------------------------- −40°C to 85°C

------------------------------------------------------------------------------------------------------- 1.4V to 5.5V

(VDD

> V

+ 1.5V) -------------------------------------------------------------------------- 3V to 5.5V

OUT

(Note 8) ----------------------------------------------------------------------- 4.5V to 5.5V

Electrical Characteristics

= V

+ 500mV, V

OUT

Parameter Symbol Test Conditions Min Typ Max Unit

POR Threshold 2.4 2.7 3 V

POR Hysteresis 0.15 0.2 -- V

Adjustable Pin Threshold V

Reference Voltage (ADJ Pin Voltage) V

Fixed Output Voltage Range ΔV

Line Regulation (VIN) ΔV

Load Regulation (Note 5) ΔV

Dropout Voltage (Note 6) V

Quiescent Current (Note 7) IQ V

Current Limit I

= V

= 5V, C

= C

= 10μF, T

OUT

TH_ADJ

ADJ

−1.5 0 1.5 %

OUT

LINE_IN

LOAD

DROP

3.2 4.5 -- A

LIM

= T

OUT

= 25°C, unless otherwise specified)

= 1mA -- 0.2 0.4 V

= 1mA 0.788 0.8 0.812 V

= V

+ 0.5V to 5V,

OUT

= 1mA

+ 1V,

OUT

= 1mA to 3A

-- 0.2 0.6 %

-- 0.2 1 %

= 2A -- 150 250

= 3A -- 210 350

= 5.5V -- 0.6 1.2 mA

DS9018A/B-09 April 2012 www.richtek.com

RT9018A/B

Parameter Symbol Test Conditions Min Typ Max Unit

Short Circuit Current

In-rush Current

Pull Low Resistance

OUT

< 0.2V 0.5 1.8 -- A

OUT

= 10μF, Enable Start-up -- 0.6 -- A

OUT

= 0V -- 150 -- Ω

Chip Enable

EN Input Bias Current IEN V

Current

EN Threshold Voltage

RT9018A -- 10 20 VDD Shutdown

RT9018B

Logic-Low V

Logic-High V

VEN = 0V

SHDN

VDD = 5V -- -- 0.7

ENL

VDD = 5V 1.2 -- --

ENH

= 0V -- 12 -- μA

-- -- 1

μA

Powe r Good

PGOOD Rising Threshold -- 90 93 %

PGOOD Hysteresis 3 10 -- %

PGOOD Sink Capability I

PGOOD

= 10mA -- 0.2 0.4 V

PGOOD Delay 0.5 1.5 5 ms

Thermal Protection

Thermal Shutdown Temperature TSD -- 160 -- °C

Thermal Shutdown Hysteresis ΔTSD -- 30 -- °C

Thermal Shutdown Temperature

Fold-back

< 0.4V -- 110 -- °C

OUT

Note 1. Stresses beyond those listed “Absolute Maximum Ratings” may cause permanent damage to the device. These are

stress ratings only, and 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 may

affect device reliability.

Note 2. θ

Note 3. Devices are ESD sensitive. Handling precaution recommended. Note 4. The device is not guaranteed to function outside its operating conditions. Note 5. Regulation is measured at constant junction temperature by using a 2ms current pulse. Devices are tested for load

Note 6. The dropout voltage is defined as V Note 7. Quiescent, or ground current, is the difference between input and output currents. It is defined by I

Note 8. The control voltage must within 4.5V to 5.5V when using PGOOD function.

is measured at T

measured at the exposed pad of the package.

regulation in the load range from 1mA to 3A.

load condition (I

current.

= 25°C on a high effective thermal conductivity four-layer test board per JEDEC 51-7. θJC is

-V

= 0mA). The total current drawn from the supply is the sum of the load current plus the ground pin

OUT

, which is measured when V

OUT

is V

OUT(NORMAL)

- 100mV.

= IIN - I

under no

OUT

DS9018A/B-09 April 2012www.richtek.com

Typical Operating Characteristics

RT9018A/B

OUT

(20mV/Div)

OUT

(1A/Div)

Load Transient Response

VDD = 5V, VIN = 1.8V, V

VIN Line Transient Response

VDD = 5V, V

OUT

= 1.2V

OUT

Time (2.5ms/Div)

= 1.2V, I

OUT

= 0A

OUT

(20mV/Div)

OUT

(1A/Div)

Load Transient Response

VDD = 5V, VIN = 1.8V, V

VIN Line Transient Response

VDD = 5V, V

OUT

= 1.2V

OUT

Time (2.5ms/Div)

= 1.2V, I

OUT

= 2A

OUT

(20mV/Div)

OUT

(20mV/Div)

Time (250μs/Div)

VDD Line Transient Response

VIN = 1.8V, V

= 1.2V, I

OUT

Time (250μs/Div)

= 0A

OUT

(20mV/Div)

OUT

(20mV/Div)

Time (250μs/Div)

VDD Line Transient Response

VIN = 1.8V, V

= 1.2V, I

OUT

Time (250μs/Div)

= 2A

DS9018A/B-09 April 2012 www.richtek.com

RT9018A/B

)

400

350

300

250

200

150

100

Dropout Voltage (mV)

(1V/Div)

OUT

(1V/Div)

PGOOD (1V/Div)

Dropout Voltage vs. Load Current

0 0.3 0.6 0.9 1.2 1.5 1.8 2.1 2.4 2.7 3

Load Current (A)

OUT

Start Up from V

= 3A

125°C

25°C

-40°C

(1V/Div)

OUT

(1V/Div)

PGOOD (1V/Div)

(2A/Div)

(5V/Div)

OUT

(1V/Div)

PGOOD (1V/Div)

OUT

Start Up from Enable

= 3A

Time (500μs/Div)

Start Up from V

= 3A

(2A/Div)

Time (1ms/Div)

Short Circuit Protection

VDD = 5V, VIN = 1.8V, V

OUT

(1A/Div)

Time (100μs/Div)

OUT

= 1.2V

(2A/Div)

2.6

2.4

2.2

2.0

1.8

1.6

1.4

1.2

Short Circuit Current Ishort (A

1.0

Time (500μs/Div)

Short Circuit Current vs . Te mp e rature

-40 -20 0 20 40 60 80 100

Temperature (°C)

DS9018A/B-09 April 2012www.richtek.com

RT9018A/B

)

VDD Standby Current vs. Temperature

VIN = 3.3V, VEN = 0V, VDD = 5V

Standby Current (μA) 1

RT9018A

RT9018B

-4

-50-25 0 25 50 75100125

Temperature (°C)

Reference Voltage vs. Temperature

0.84

0.83

0.82

0.81

0.80

0.79

0.78

Reference Voltage (V)

0.77

0.76

-40 -25 -10 5 20 35 50 65 80 95 110 125

Temp erature (°C)

Quiescent Current vs. Temperature

1200

1.2

1100

1.1

1000

1.0

900

0.9

800

0.8

700

0.7

600

0.6

500

0.5

400

0.4

300

0.3

Quiescent Current (uA

Quiescent Current (mA)

200

0.2

100

0.1

-40 -25 -10 5 20 35 50 65 80 95 110 125

VIN = 1.8V, V

OUT

= 1.2V, I

Temperature (°C)

Output Voltage vs. Temperature

1.25

VIN = 1.8V, V

1.24

1.23

1.22

1.21

1.20

1.19

1.18

Output Voltage (V)

1.17

1.16

1.15

-40 -25 -10 5 20 35 50 65 80 95 110 125

ADJ

= 0V, I

OUT

= 0A

Temperature (°C)

OUT

= 0A

VDD POR Threshold Voltage vs. Temperature

3.00

2.95

2.90

2.85

2.80

2.75

2.70

2.65

2.60

POR Voltage (V)

2.55

2.50

2.45

2.40

-40 -25 -10 5 20 35 50 65 80 95 110 125

Rising

Falling

Temperature (°C)

ADJ Threshold Voltage vs. Temperature

0.30

0.28

0.26

0.24

0.22

0.20

0.18

0.16

0.14

0.12

ADJ Threshold Voltage Range (V

0.10

-40 -25 -10 5 20 35 50 65 80 95 110 125

Temp erature (°C)

DS9018A/B-09 April 2012 www.richtek.com

RT9018A/B

Over Current Protection Fold Back

VIN = VEN = 3.3V, VDD = 5V

2.5

(V)

OUT

1.5

Output Voltage V

0.5

0 0.5 1 1.5 2 2.5 3 3.5 4

Loading Current I

OUT

(A)

DS9018A/B-09 April 2012www.richtek.com

Application Information

RT9018A/B

Adjustable Mode Operation

The output voltage of RT9018A/B is adjustable from 0.8V

to (VIN - V

) by external voltage divider resisters as

DROP

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

+ 1.5V).

OUT

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 Capa citor

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.

Power Good

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

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 (V

< 0.4V). It limits

OUT

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 = (V

− V

OUT

) x I

+ VIN x I

OUT

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 :

Where T

temperature 125°C, T

D(MAX)

= (T

− TA) / θ

J(MAX)

is the maximum operation junction

J(MAX)

is the ambient temperature and the

θJA is the junction to ambient thermal resistance.

For recommended operating conditions specification,

where T

is the maximum junction temperature of

J (MAX)

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

DS9018A/B-09 April 2012 www.richtek.com

RT9018A/B

formula :

= (125°C − 25°C) / (75°C/W) = 1.33W (SOP-8

D (MAX)

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, θ

= 51°C/W

Figure 3 (e). Copper Area = 70mm2, θJA = 49°C/W

Figure 3. Thermal Resistance vs. Different Cooper Area

Layout Design

Figure 3 (a). Minimum Footprint, θ

Figure 3 (b). Copper Area = 10mm2, θ

= 75°C/W

= 64°C/W

The maximum power dissipation depends on operating

ambient temperature for fixed T

resistance θ

. The Figure 4 of de-rating curves allows

and thermal

J(MAX)

the designer to see the effect of rising ambient temperature

on the maximum power allowed.

2.2

1.8

1.6

1.4

1.2

0.8

0.6

Power Dissipation (W)

0.4

0.2

JEDEC 4-Layers PCB

0 20 40 60 80 100 120 140

Ambient Temperature (°C)

Copper Area

70mm

50mm

30mm

10mm

Minimum Layout

Figure 4. De-rating Curves

Figure 3 (c). Copper Area = 30mm2, θ

= 54°C/W

DS9018A/B-09 April 2012www.richtek.com

Outline Dimension

RT9018A/B

EXPOSED THERMAL PAD (Bottom of Package)

Dimensions In Millimeters Dimensions In Inches

Symbol

Min Max Min Max

A 4.801 5.004 0.189 0.197

B 3.810 4.000 0.150 0.157

Option 1

Option 2

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

8-Lead SOP (Exposed Pad) Plastic Package

DS9018A/B-09 April 2012 www.richtek.com

RT9018A/B

SEE DETAIL A

DETAIL A

Pin #1 ID and Tie Bar Mark Options

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 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 0.500 0.020

L 0.350 0.450

W-Type 10L DFN 3x3 Package

0.014 0.018

Richtek Technology Corporation

5F, No. 20, Taiyuen Street, Chupei City

Hsinchu, Taiwan, R.O.C.

Tel: (8863)5526789

Richtek products are sold by description only. Richtek reserves the right to change the circuitry and/or specifications without notice at any time. Customers should

obtain the latest relevant information and data sheets before placing orders and should verify that such information is current and complete. Richtek cannot

assume responsibility for use of any circuitry other than circuitry entirely embodied in a Richtek product. Information furnished by Richtek is believed to be

accurate and reliable. However, no responsibility is assumed by Richtek or its subsidiaries for its use; nor for any infringements of patents or other rights of third

parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Richtek or its subsidiaries.

DS9018A/B-09 April 2012www.richtek.com

Richtek RT9018A-10GQW, RT9018A-12GQW, RT9018A-12PQW, RT9018A-15GQW, RT9018A-18GQW Schematic [ru]

Specifications and Main Features

Frequently Asked Questions

User Manual