Richtek RT9293A-20GJ6, RT9293A-20GQWA, RT9293AGJ6, RT9293AGQW, RT9293AGQWA Schematic [ru]

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RT9293

Small Package, High Performance, Asynchronies Boost for 10 WLED Driver

General Description

The RT9293 is a high frequency, asynchronous boost converter. The internal MOSFET can support up to 10 White LEDs for backlighting and OLED power application, and the internal soft start function can reduce the inrush current. The device operates with 1-MHz fixed switching frequency to allow small external components and to simplify possible EMI problems. For the protection, the RT9293A provides 50V OVP and the RT9293B provides 50V/20V OVP to allow inexpensive and small-output capacitors with lower voltage ratings. The LED current is initially set with the external sense resistor RSET. The RT9293 is available in the tiny package type TSOT-23-6 and WDFN-8L 2x2 packages to provide the best solution for PCB space saving and total BOM cost.

Features

zVIN Operating Range : 2.5V to 5.5V

zInternal Power N-MOSFET Switch

zWide Range for PWM Dimming (100Hz to200kHz)

zMinimize the External Component Counts

zInternal Soft Start

zInternal Compensation

zUnder Voltage Protection

zOver Voltage Protection

zOver Temperature Protection

zSmall TSOT-23-6 and 8-Lead WDFN Packages

zRoHS Compliant and Halogen Free

Applications

zCellular Phones

zDigital Cameras

Ordering Information

RT9293 (-)

Package Type

J6 : TSOT-23-6

QW : WDFN-8L 2x2 (W-Type)

Lead Plating System

G : Green (Halogen Free and Pb Free)

OVP Voltage

Default : 50V (RT9293A/B) 20 : 20V (RT9293B)

Feedback Voltage Reference A : 104mV

B : 300mV

Note :

Richtek products are :

`RoHS compliant and compatible with the current requirements of IPC/JEDEC J-STD-020.

`Suitable for use in SnPb or Pb-free soldering processes.

zPDAs and Smart Phones and MP3 and OLED.

zPortable Instruments

Pin Configurations

(TOP VIEW)

VIN VOUT EN

6

 

5

4

 

 

 

2

3

 

LX

 

GND FB

TSOT-23-6

 

GND

1

GND

8

LX

VIN

2

7

NC

VOUT

3

9

6

FB

EN

4

5

GND

 

WDFN-8L 2x2

Marking Information

For marking information, contact our sales representative directly or through a Richtek distributor located in your area.

DS9293-01 April 2011

www.richtek.com

1

RT9293

Typical Application Circuit

 

 

L

 

D

 

 

22µH to 47µH

 

VOUT

 

 

 

 

 

 

 

 

LX

VOUT

 

 

VIN

 

 

COUT

 

 

CIN

VIN

1µF

 

 

 

RT9293

10 WLEDs

 

 

2.2µF

 

 

 

 

 

Chip Enable

 

EN

 

 

 

 

 

 

 

 

 

 

GND

FB

 

 

 

 

 

 

RSET

Functional Pin Description

 

 

 

Pin No.

Pin Name

 

 

Pin Function

RT9293GJ6

RT9293GQW

 

 

 

 

 

 

1

8

LX

Switching Pin.

 

2

1, 5,

GND

Ground Pin. The exposed pad must be soldered to a large

9 (Exposed pad)

PCB and connected to GND for maximum power dissipation.

 

 

3

6

FB

Feedback Pin, put a resistor to GND to setting the current.

4

4

EN

Chip Enable (Active High).

5

3

VOUT

Output Voltage Pin.

 

6

2

VIN

Input Supply.

 

--

7

NC

No Internal Connection.

 

Function Block Diagram

 

 

VIN

 

 

 

LX

 

 

 

 

UVLO

 

 

OVP

VOUT

 

 

 

 

 

 

 

 

 

 

Internal

 

 

 

 

 

OCP

 

 

 

 

 

 

 

 

 

 

 

 

Compensation

 

OTP

Logic Control,

 

 

 

 

 

 

 

Current-

 

 

 

Internal

 

 

PWM

Minimum On

 

 

 

 

-

 

Time

Sense

 

 

 

Soft Start

 

 

 

 

 

 

 

 

 

+

 

 

 

 

 

 

 

 

 

+

 

 

 

Driver

 

 

 

 

 

 

 

 

 

 

 

 

EA

 

 

 

 

 

 

GND

 

 

GM

 

 

Slope

 

 

 

 

 

 

+ -

 

Compensation

Shutdown

PWM

 

 

 

 

 

 

Enable

 

 

 

 

 

 

LPF

20ms

Oscillator

 

 

 

 

 

Logic

 

 

 

 

 

 

 

 

 

 

Reference

 

 

 

 

 

 

 

 

 

 

 

 

 

VREF

 

 

 

Voltage

 

 

 

 

 

 

1µA

Bias

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Current

 

 

 

FB

 

 

EN

 

 

 

 

 

 

www.richtek.com

 

 

 

 

 

 

DS9293-01

April

2011

2

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

RT9293

Absolute Maximum Ratings (Note 1)

 

 

 

 

 

 

z Supply Input Voltage, VIN ------------------------------------------------------------------------------------------------

 

 

 

 

0.3V to 6V

z Switching Pin, LX ----------------------------------------------------------------------------------------------------------

 

 

 

 

 

−0.3V to 50V

z VOUT -------------------------------------------------------------------------------------------------------------------------

 

 

 

 

 

−0.3V to 46V

z Other Pins-------------------------------------------------------------------------------------------------------------------

 

 

 

 

 

−0.3V to 6V

z Power Dissipation, PD @ TA = 25°C

 

 

 

 

 

 

 

 

TSOT-23-6 -------------------------------------------------------------------------------------------------------------------

 

 

 

 

 

0.392W

 

 

WDFN−8L 2x2 --------------------------------------------------------------------------------------------------------------

 

 

 

 

 

0.606W

 

 

z Package Thermal Resistance (Note 2)

 

 

 

 

 

 

 

TSOT-23-6, θJA -------------------------------------------------------------------------------------------------------------

 

 

 

 

 

255°C/W

 

 

WDFN−8L 2x2, θJA --------------------------------------------------------------------------------------------------------

 

 

 

 

 

165°C/W

 

 

WDFN−8L 2x2, θJC --------------------------------------------------------------------------------------------------------

 

 

 

 

 

20°C/W

 

 

z Lead Temperature (Soldering, 10 sec.) -------------------------------------------------------------------------------

 

 

 

260°C

 

 

z Junction Temperature -----------------------------------------------------------------------------------------------------

 

 

 

 

 

150°C

 

 

z Storage Temperature Range --------------------------------------------------------------------------------------------

 

 

 

 

65°C to 150°C

Recommended Operating Conditions (Note 3)

 

 

 

 

 

 

z Junction Temperature Range --------------------------------------------------------------------------------------------

 

 

 

 

−40°C to 125°C

z Ambient Temperature Range --------------------------------------------------------------------------------------------

 

 

 

 

−40°C to 85°C

Electrical Characteristics

 

 

 

 

 

 

 

(VIN = 3.7V, CIN = 2.2μF, COUT = 0.47μF, IOUT = 20mA, L = 22μH, TA = 25°C, unless otherwise specified)

 

 

 

 

Parameter

 

Symbol

Test Conditions

Min

Typ

Max

 

Unit

 

 

 

 

 

 

 

 

 

 

 

 

Input Voltage

 

VIN

 

2.5

--

5.5

 

V

 

Under Voltage Lock Out

VUVLO

 

2

2.2

2.45

 

V

 

 

 

 

 

 

 

 

 

 

 

 

UVLO Hysteresis

 

 

 

--

0.1

--

 

V

 

 

 

 

 

 

 

 

 

 

 

 

Quiescent Current

 

IQ

FB = 1.5V, No Switching

--

400

600

 

μA

 

Supply Current

 

IIN

FB = 0V, Switching

--

1

2

 

mA

 

 

 

 

 

 

 

 

 

 

 

 

Shutdown Current

 

ISHDN

VEN < 0.4V

--

1

4

 

μA

 

Line Regulation

 

 

VIN = 3 to 4.3V

--

1

--

 

%

 

Load Regulation

 

 

1mA to 20mA

--

1

--

 

%

 

 

 

 

 

 

 

 

 

 

 

 

Operation Frequency

 

fOSC

 

0.75

1

1.25

 

MHz

 

Maximum Duty Cycle

 

 

 

90

92

--

 

%

 

 

 

 

 

 

 

 

 

 

 

 

Clock Rate

 

 

 

0.1

--

200

 

kHz

 

 

 

 

 

 

 

 

 

 

 

Feedback Reference

RT9293A

VREF

 

94

104

114

 

mV

 

Voltage

 

RT9293B

 

285

300

315

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

On Resistance

 

RDS(ON)

 

--

0.7

1.2

 

Ω

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

To be continued

 

 

 

 

 

 

 

 

 

 

DS9293-01 April 2011

 

 

 

 

 

www.richtek.com

3

RT9293

Parameter

Symbol

Test Conditions

Min

Typ

Max

Unit

 

 

 

 

 

 

 

 

EN Threshold

Logic-High

VIH

 

1.4

--

--

V

Voltage

Logic-Low

VIL

 

--

--

0.5

 

 

EN Sink Current

 

IIH

 

--

1

--

μ

 

 

 

 

 

 

A

EN Hysteresis

 

 

 

--

0.1

--

V

 

 

 

 

 

 

 

 

Over-Voltage

OVP = 50V

VOVP

 

42

46

50

V

Threshold

RT9293B-20

 

16

17.5

20

 

 

 

 

 

 

 

 

 

 

 

Over-Current Threshold

IOCP

 

1

1.2

--

A

OTP

 

TOTP

 

--

160

--

°C

OTP Hysteresis

 

 

 

--

30

--

°C

Shutdown Delay

 

TSHDN

 

--

20

--

ms

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 low effective single layer thermal conductivity test board of JEDEC 51-3 thermal measurement standard. The case point of θJC is on the expose pad for the WDFN package.

Note 3. The device is not guaranteed to function outside its operating conditions.

www.richtek.com

DS9293-01 April 2011

4

Richtek RT9293A-20GJ6, RT9293A-20GQWA, RT9293AGJ6, RT9293AGQW, RT9293AGQWA Schematic

RT9293

Typical Operating Characteristics

Efficiency vs. Output Current

 

100

 

 

 

 

VIN = 4.5V

 

90

 

 

 

 

 

 

 

 

 

 

 

 

80

 

 

 

 

VIN = 4V

(%)

70

 

 

 

 

 

 

60

 

 

 

 

 

 

Efficiency

 

 

 

 

 

 

50

 

 

 

 

 

 

40

 

 

 

 

 

 

30

 

 

 

 

 

 

 

 

 

 

 

 

 

 

20

 

 

 

 

 

 

 

10

 

 

 

 

VOUT = 10V

 

0

 

 

 

 

 

 

 

 

 

 

 

 

0

0.05

0.1

0.15

0.2

0.25

0.3

Efficiency vs. Input Voltage

 

100

 

 

 

 

 

 

 

90

 

 

 

 

ILOAD = 30mA

 

 

 

 

 

 

 

 

80

 

 

 

 

ILOAD = 10mA

 

70

 

 

 

 

(%)

 

 

ILOAD = 20mA

 

 

60

 

 

 

 

 

 

 

 

 

 

Efficiency

 

 

 

 

 

 

50

 

 

 

 

 

 

40

 

 

 

 

 

 

30

 

 

 

 

 

 

 

 

 

 

 

 

 

 

20

 

 

 

 

 

 

 

10

 

 

 

 

VOUT = 34V

 

0

 

 

 

 

 

 

 

 

 

 

 

 

2.5

3

3.5

4

4.5

5

5.5

Output Current (A)

Input Voltage (V)

Output Voltage vs. Output Current

Quiescent Current vs. Input Voltage

 

40

 

 

 

 

 

 

 

 

500

 

35

 

 

 

 

 

 

 

Quiescent Current (µA)

450

Output Voltage (V)

30

 

 

 

 

 

 

 

400

25

 

 

 

 

 

 

 

350

20

 

 

 

 

 

 

 

300

15

 

 

 

 

 

 

 

250

 

 

 

 

 

 

 

 

 

 

10

 

 

 

 

VIN = 3.7V, VOUT = 34V

200

 

 

 

 

 

 

 

 

 

 

5

15

25

35

45

55

65

75

85

 

 

 

 

 

 

VFB = 1.5V

2.5

3

3.5

4

4.5

5

5.5

Output Current (mA)

Input Voltage (V)

Frequency vs. Input Voltage

Frequency vs. Temperature

 

1100

 

 

 

 

 

 

1100

 

1050

 

 

 

 

 

 

1050

(kHz)

1000

 

 

 

 

 

(kHz)

1000

 

 

 

 

 

 

 

Frequency

950

 

 

 

 

 

Frequency

950

900

 

 

 

 

 

900

 

 

 

 

 

 

 

 

850

 

 

 

 

 

 

850

 

800

 

 

 

 

ILED = 20mA

800

 

 

 

 

 

 

 

 

2.5

3

3.5

4

4.5

5

5.5

 

 

 

 

 

 

 

VIN = 3.7V, ILED = 20mA

-40

-25

-10

5

20

35

50

65

80

95 110 125

Input Voltage (V)

Temperature (°C)

 

 

DS9293-01 April 2011

www.richtek.com

5

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