Diodes AP3031 User Manual

Data Sheet

WHITE LED STEP-UP CONVERTER AP3031

General Description

The AP3031 is an inductor-based DC/DC boost converter designed to drive LED arrays. 1.4A switching current allows AP3031 to be used in different 7' to 10' LCD panel backlights (3*13 LED arrays typically).

A constant frequency 1MHz PWM control scheme is employed in this IC, which means tiny external components can be used. Specifically, 1mm tall 4.7 inductor and 0.47 application is sufficient.

The over output voltage protection is equipped in AP3031, which protects the IC under open load condition. The AP3031 includes UVLO, soft-start, current limit and OTSD to protect the circuit.

The AP3031 is available in standard SOT-23-6, TSOT23-6 and SOIC-8 packages.

μF output capacitor for the typical

μH

Features

· Up to 92% Efficiency

(V

· Up to 84% Efficiency

(V

· Fast 1MHz Switching Frequency

· Wide Input Voltage Range: 2.7V to 16V

· Low 200mV Feedback Voltage

· Output Over Voltage Protection

· Cycle by Cycle Current Limit: 1.4A

· Built-in Soft-start

· Built-in Standby Mode to Achieve High Fre-

· Built-in Thermal Shutdown Function

· Under Voltage Lockout

=9V, I

IN

=5V, I

IN

quency PWM Dimming

OUT

=260mA)

Applications

· 7' to 10' LCD Panels

· Digital Photo Frame

· GPS Receiver

· EPC

· PDVD

SOT-23-6 TSOT-23-6 SOIC-8

Figure 1. Package Types of AP3031

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Data Sheet

1

2

3

4

8

7

6

5

1

2

34

5

Pin 1 Mark

6

WHITE LED STEP-UP CONVERTER AP3031

Pin Configuration

K/KT Package

(SOT-23-6/TSOT-23-6)

SW

GND

FB

V

IN

OV

CTRL

FB

GND

SW

M Package

(SOIC-8)

CTRL

OV

GND

V

IN

Figure 2. Pin Configuration of AP3031 (Top View)

Pin Description

Pin Number

6-Pin 8-Pin

1 4 SW Switch Pin. Connect external inductor and Schottky

2 2, 3, 6 GND Ground Pin

3 1 FB Voltage Feedback Pin. Reference voltage is 200mV

4

5 7 OV Over-voltage Protection Input Pin. Connect to the output directly. On OVP condition, the out-

65 V

Pin Name Function

Enable and Dimming Control Pin. Connect to a high input to enable the IC or a low input to disable the IC.

8CTRL

If logic low time is more than about 0.7ms and then enable the IC, the AP3031 will soft start to protect system departments. If logic low time is less than about 0.7ms and then enable the IC, the AP3031 will hold on standby mode and start directly to achieve high frequency dimming

put voltage will be clamped

Input Supply Pin. Must be locally bypassed

IN

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Data Sheet

Q1

Σ

A2

A1

1MHz

OSCILLATOR

RAMP

GENERATOR

V

REF

DRIVER

1.25 V

COMPARATOR

200 mV

SOFT

START

V

IN

CTRL

FB

GND

SW

STANDBY

OV

To Control

Logic

CONTROL

LOGIC

OVER

TEMPERATURE

DETECTOR

OV

WHITE LED STEP-UP CONVERTER AP3031

Functional Block Diagram

3 (1)

6 (5)

4 (8)

A (B) A SOT-23-6/TSOT-23-6 B SOIC-8

1 (4)

5 (7)

2 (2, 3, 6)

Figure 3. Functional Block Diagram of AP3031

Ordering Information

AP3031 -

Circuit Type

Package

K: SOT-23-6

KT: TSOT-23-6

M: SOIC-8

Temperature

Range

o

-40 to 85

C

Part Number Marking ID Packing Type

AP3031KTR-G1 GEC Tape & Reel

AP3031M-G1 3031M-G1 Tube

AP3031MTR-G1 3031M-G1 Tape & Reel

3

Package

SOT-23-6

TSOT-23-6 AP3031KTTR-G1 L1E Tape & Reel

SOIC-8

BCD Semiconductor's Pb-free products, as designated with "G1" suffix in the part number, are RoHS compliant and green.

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G1: Green

TR: Tape and Reel Blank: Tube

Data Sheet

WHITE LED STEP-UP CONVERTER AP3031

Absolute Maximum Ratings (Note 1)

Parameter Symbol Value Unit

Input Voltage V

SW Voltage V

FB Voltage V

CTRL Voltage V

Thermal Resistance (Junction to Ambient, No Heat Sink) θ

Operating Junction Temperature T

Storage Temperature Range T

Lead Temperature (Soldering, 10sec) T

LEAD

IN

SW

FB

CTRL

JA

J

STG

SOT-23-6/TSOT-23-6 265

SOIC-8 120

20 V

38 V

20 V

150

-65 to 150

260

o

C/W

o

C

o

C

o

C

ESD (Machine Model) 600 V

ESD (Human Body Model) 4000 V

Note 1: Stresses greater than those listed under "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 under "Recommended Operating Conditions" is not implied. Exposure to "Absolute Maximum Ratings" for extended periods may affect device reliability.

Recommended Operating Conditions

Parameter Symbol Min Max Unit

Operating Temperature Range T

Input Voltage V

CTRL Voltage V

-40 85

OP

IN

CTRL

2.7 16

16 V

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o

C

V

Data Sheet

WHITE LED STEP-UP CONVERTER AP3031

Electrical Characteristics

(VIN=5.0V, V

=5.0V, TA=25oC, unless otherwise specified.)

CTRL

Parameter Symbol Conditions Min Typ Max Unit

Operating Voltage V

Feedback Voltage (Note 2)

FB Pin Bias Current I

Quiescent Current I

Shutdown Quiescent Current I

IN

V

FB

Q

SHDN

I

=20mA, 3 LEDs,

OUT

T

=-40oC to 85oC

A

VFB=VIN, no switching 3.0 4.0 5.0 mA

V

=0V 20 50 80 μA

CTRL

2.7 16

188 200 212 mV

35 100 nA

Switching Frequency f 0.75 1 1.3 MHz

Maximum Duty Cycle D

Switch Current Limit (Note 3) I

Switch V

Saturation Voltage V

CE

MAX

LIMIT

CESATISW

Switch Leakage Current V

CTRL Pin Voltage

V

CTRL

D=60% 1.2 1.4 A

=0.6A 300 mV

=16V 0.01 5 μA

SW

Active high 1.8

90 93 %

Active low 0.5

CTRL Pin Bias Current I

CTRL

35 60 85 μA

V

OVP Voltage V

Soft-start Time t

Standby Time t

Thermal Shutdown T

Thermal Resistance (Junction to Case)

OVP

SS

STB

OTSD

θ

JC

15.5 17.5 19.5 V

250 μs

0.7 ms

155

60

o

C/W

C

Note 2: The bold type specifications of full temperature range are guaranteed by design (GBD). Note 3: The switch current limit is related to duty cycle. Please refer to Figure 15 for detail.

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Data Sheet

0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 320 340

45

50

55

60

65

70

75

80

85

90

Efficiency (%)

Output Current (mA)

VIN=5V, V

OUT

=10V, TA=25oC

C

IN

=10μF, C

OUT

=0.47μF, L=4.7μH

3.54.04.55.05.56.06.57.07.58.08.59.09.5

50

55

60

65

70

75

80

85

90

95

Efficiency (%)

Input Voltage (V)

V

OUT

=10V, I

OUT

=260mA,TA=25oC

C

IN

=10μF, C

OUT

=0.47μF, L=4.7μH

-60 -40 -20 0 20 40 60 80 100 120 140

2.20

2.25

2.30

2.35

2.40

2.45

2.50

2.55

2.60

2.65

2.70

Minimum Operating Voltage (V)

Temperature (oC)

2 4 6 8 10 12 14 16

3.7

3.8

3.9

4.0

4.1

4.2

4.3

4.4

4.5

4.6

4.7

Quiescent Current (mA)

Input Voltage (V)

TA= -40oC

TA= 25oC

TA= 85oC

WHITE LED STEP-UP CONVERTER AP3031

Typical Performance Characteristics

(WLED forward voltage (VF)=3.2V at IF=20mA, unless otherwise noted.)

Figure 4. Efficiency vs. Output Current Figure 5. Efficiency vs. Input Voltage

Figure 6. Minimum Operating Voltage vs. Temperature Figure 7. Quiescent Current vs. Input Voltage

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