Diodes AP3156 User Manual

AP3156

HIGH EFFICIENCY 1X/1.5X/2X CHARGE PUMP

FOR WHITE LED APPLICATIONS

Features

• VIN Range: 2.7V to 5.5V

• Fully Programmable Current with Single Wire

• 32-Step Logarithmic Scale

• 20/25mA Max Current per Channel

• Four Low Current Settings Down to 50µA

(50µA) for Low Current Mode

• Low I

Q

Coverage

F

<1µA in Shutdown

Q

in “Green” Molding Compound (No Br, Sb)

• Tri-Mode 1X, 1.5X, and 2X Charge Pump for Maximum Efficiency and V

• Drives up to Six Channels of LEDs

• Individual Main/Sub-Group Control

• No Inductors, Low Noise Operation

• 0.5/1/2MHz Constant Switching Frequency

• Small Application Circuit

• Built-In Thermal Protection

• Built-In Auto-Disable For Open Circuit

• Automatic Soft Start

• I

• Thermally-Enhanced QFN4040-16 Package: Available

• Lead Free Finish / RoHS Compliant (Note 1)

Applications

• Color (RGB) Lighting

• Programmable Current Sinks

• White LED Backlighting

• White Photo Flash for Digital Still Cameras

Typical Application Circuit

General Description

The AP3156 is a low noise, constant frequency charge pump DC/DC converter that uses a tri-mode load switch (1X), fractional (1.5X), and doubling (2X) conversion to maximize efficiency for white LED applications. The AP3156 is capable of driving the LED channels at 120mA maximum from a 2.7V to 5.5V input. The current sinks may be operated individ ually or in pa rallel fo r driving higher-current LEDs. A low external parts count (two 1µF flying capacitors and two small 1µF capacitors at V this part ideally suited for small, battery-powered applications.

AP3156 serial digital input is used to enable, disable and set current for each LED with a 32-level logarithmic scale plus four low-current settings down to 50µA for optimized efficiency, with a low quiescent current of only 50µA.

Each output of the AP3156 is equipped with built-in protection for

short circuit and auto-disable for LED failure conditions.

V

OUT

Built-in soft-start circuitry prevents excessive inrush current during start-up. A low-current shutdown feature disconnects the load from V

The AP3156 is available in a lead-free, space-saving, thermally enhanced 16-pin 4x4mm QFN package.

and reduces quiescent current to less than 1µA.

IN

and V

IN

OUT

) make

10

V

SDI

IN

1uF

C

IN

V

IN

AP3156

2

SDI

GND

9,11

AP3156 Rev. 1 1 of 15 SEPTEMBER 2009

5

C2

P

C2

N

C1

P

C1

V

OUT

D6 D5 D4 D3 D2 D1

1uF

C

2

8 6

1uF

C

1

7

N

4

15 14 13 12

16

LED

1

D4

D3

D6

D5

LED

D2

LEDD1LED

1uF

C

OUT

www.diodes.com © Diodes Incorporated

Ordering Information

AP3156

HIGH EFFICIENCY 1X/1.5X/2X CHARGE PUMP

FOR WHITE LED APPLICATIONS

AP 3156 FV G - 7

Package

FV : QFN4040-16

Device

AP3156FVG-7 FV QFN4040-16 1500/Tape & Reel -7

Notes: 1. EU Directive 2002/95/EC (RoHS). All applicable RoHS exemptions applied. Please visit our website at

http://www.diodes.com/datasheets/ap02001.pdf.

http://www.diodes.com/products/lead_free.html

2. Pad layout as shown on Diodes Inc. suggested pad layout document AP02001, which can be found on our website at

Package

Code

Packaging

(Note 2)

G : Green

Quantity Part Number Suffix

PackingLead Free

7 : Tape & Reel

7” Tape and Reel

Pin Assignments

(Top View)

D6

SDI

NC

D5 16

1 2

Exposed

3

D4 15

Pad

D3 14

D2

13

12 11 10

D1 GND

V

IN

V

OUT

AP3156 Rev. 1 2 of 15 SEPTEMBER 2009

4

7

6

5

P

C2

QFN4040-16

www.diodes.com © Diodes Incorporated

P

C1

N

C1

8

N

C2

9

GND

g

AP3156

HIGH EFFICIENCY 1X/1.5X/2X CHARGE PUMP

FOR WHITE LED APPLICATIONS

Pin Descriptions

Pin Name

D6 1 Current Sink Input #6. Connected to VOUT when un-used.

SDI 2 Serial Digital Interface Control Pin

NC 3 No Connection

VOUT 4

C2P 5 C1P 6

C1N 7 Negative Terminal of Flying Capacitor 1 C2N 8 Negative Terminal of Flying Capacitor 2

GND 9, 11 Ground.

VIN 10 Input Power Supply. Requires 1µF capacitor between this pin and ground.

D1 12 Current sink input #1. Connected to VOUT when un-used. D2 13 Current sink input #2. Connected to VOUT when un-used. D3 14 Current sink input #3. Connected to VOUT when un-used. D4 15 Current sink input #4. Connected to VOUT when un-used. D5 16 Current sink input #5. Connected to VOUT when un-used.

GND EP PAD Exposed Pad (bottom). Connected to GND directly underneath the package.

Functional Block Diagram

Number

Description

Charge pump output to drive load circuit. Requires 1µF capacitor connected between this pin and Positive Terminal of Flying Capacitor 2. Connects a 1µF capacitor between C2 C2

N.

Positive terminal of Flying Capacitor 1. Connects a 1µF capacitor between C1

N.

C1

round

P and

AP3156 Rev. 1 3 of 15 SEPTEMBER 2009

www.diodes.com © Diodes Incorporated

r

AP3156

HIGH EFFICIENCY 1X/1.5X/2X CHARGE PUMP

FOR WHITE LED APPLICATIONS

Absolute Maximum Ratings (Note 3)

Symbol Description Rating Unit

ESD HBM Human Body Model ESD Protection 2 KV

ESD MM Machine Model ESD Protection 200 V

VIN Input Voltage -0.3 to 6 V

V

SDI to GND Voltage -0.3 to VIN +0.3 V

SDI

I

Maximum DC Output Current 150 mA

OUT

TJ Operating Junction Temperature Range -40 to 150

T

Maximum Soldering Temperature (at leads, 10 sec) 300

LEAD

Notes: 3. Exceeding Absolute Maximum Ratings will cause permanent damage to the device.

Recommended Operating Conditions

Symbol Paramete

VIN Input Voltage 2.7 5.5 V

TA Operating Ambient Temperature -40 85 °C

Min Max Units

°C °C

AP3156 Rev. 1 4 of 15 SEPTEMBER 2009

www.diodes.com © Diodes Incorporated

)

AP3156

HIGH EFFICIENCY 1X/1.5X/2X CHARGE PUMP

FOR WHITE LED APPLICATIONS

Electrical Characteristics

= C

C

IN

Symbol Parameter Test Conditions Min Typ. Max Unit

Charge Pump Section

SDI

Notes: 4. Determined by the average current levels of all active channels

5. Sequence setting set to give nominal 20mA max output current and 4mA output current.

6. Defined as the deviation of any sink current from the average of all active current channels

7. Device mounted on FR-4 substrate, 2"*2", 2oz, copper, double-sided PC board,

AP3156 Rev. 1 5 of 15 SEPTEMBER 2009

= C1 = C2 = 1.0µF; TA = 25°C, VIN = 3.5V. Unless otherwise noted.

OUT

IQ Quiescent Current

1X Mode, 3.0 No Load Current

1.5X Mode, 3.0≤V No Load Current 2X Mode, 3.0≤V No Load Current

≤VIN≤5.5, Active,

≤5.5, Active,

IN

≤5.5, Active,

IN

0.3 1

2.0 3

1.5 3

mA

50µA Setting, 1X Mode 50 µA

I

Sh utdown Curre nt SDI = 0 1 µA

SHDN

IDX

I

D-Match

I

Current Accuracy

SINK

(Note 4) Current Matching Between Any

Two Current Sink Inputs (Note 6)

= 20mA (Note 5), TA = 25°C

I

SET

I

= 4mA (Note 5), TA = 25°C

SET

V

:

F

D1:D6 = 3.6V

18.6 20 21.4 mA

3.6 4 4.4 mA

0.5 %

1X to 1.5X or 1.5X to 2X

VTH

Transition Threshold at Any

I

SINK

I

= 25mA 150 mV

SET

TSS Soft-Start Time 40 µs

0.5/

F

Clock Frequency

CLK

1/

MHz

2

V

SDI Threshold Low VIN = 2.7V 0.4 V

SDI(L

V

SDI Threshold High VIN = 5.5V 1.4 V

SDI(H

T

SDI Low Time 0.3 50 µs

SLO

T

SDI High Time 0.05 50 µs

SHI

T

SDI Off Timeout 256 µs

OFF

T

SDI Valid Sequence Timeout 256 µs

SEP

I

SDI Input Leakage -1 1 µA

SDI

θ

JA

Thermal Resistance Junction-to-Ambient

QFN4040-16 (Note 7) 46 oC/W