Diodes AP3513E User Manual

AP3513E

Document number: DS36692 Rev. 2 - 2

1 of 11

www.diodes.com

January 2014

AP3513E

A Product Line of

Diodes Incorporated

NE W P R OD UC T

Description

The AP3513E is a 500kHz fixed frequency, current mode, PWM synchronous buck (step-down) DC-DC converter, capable of driving a 3A load with high efficiency, excellent line and load regulation. The AP3513E exhibits high efficiency at light load. The device integrates N-channel power MOSFET switch with low on-resistance. Current mode control provides fast transient response and cycle-by-cycle current limit.

The AP3513E employs complete protection to ensure system security, including output Over Voltage Protection, input Under Voltage Lock Out, programmable Soft-start, Over Temperature Protection and hiccup mode Short Circuit Protection.

This IC is available in SO-8EP package.

Features

 Input Voltage Range: 4.5V to 18V  Fixed 500kHz Frequency  High Efficiency at Light Load  Output Current: 3A  Current Mode Control  Built-in Over Current Protection  Built-in Thermal Shutdown Function  Built-in UVLO Function  Built-in Over Voltage Protection  Programmable Soft-start  Hiccup Mode SCP  Totally Lead-Free & Fully RoHS Compliant (Notes 1 & 2)  Halogen and Antimony Free. “Green” Device (Note 3)

Pin Assignments

(Top View)

(SO-8EP/ MP Package)

Applications

 Monitor  TV  STB  Datacom

C

OUT

22μF*2

L

R

EN

100k

R2

R1

R

C

P

Optional

C

BS

10nF

C

SS

0.1μF

3

5

1

6

7

8

2

4

AP3513E

BS

IN

SW

GND

FB

COMP

EN

SS

Input Voltage=12V

Output Voltage=3.3V

C

IN

10μF*2

4.7μH

3.3nF

13k

10k

26.1k

1

2

3

4

8

7

6

5

BS

IN

SW

GND

SS

EN

COMP

FB

EP

18V, 3A SYNCHRONOUS DC-DC BUCK CONVERTER

Notes: 1. No purposely added lead. Fully EU Directive 2002/95/EC (RoHS) & 2011/65/EU (RoHS 2) compliant.

2. See http://www.diodes.com/quality/lead_free.html for more information about Diodes Incorporated’s definitions of Halogen- and Antimony-free, "Green" and Lead-free.

3. Halogen- and Antimony-free "Green” products are defined as those which contain <900ppm bromine, <900ppm chlorine (<1500ppm total Br + Cl) and <1000ppm antimony compounds.

Typical Applications Circuit

AP3513E

Document number: DS36692 Rev. 2 - 2

2 of 11

www.diodes.com

January 2014

AP3513E

A Product Line of

Diodes Incorporated

NE W P R OD UC T

Pin Number

Pin Name

Function

1

BS

Bootstrap pin. A bootstrap capacitor is connected between the BS pin and SW pin. The voltage across the bootstrap capacitor drives the internal high-side NMOS switch.

2

IN

Supply input pin. A capacitor should be connected between the IN pin and GND pin to keep the DC input voltage constant.

3

SW

Power switch output pin. This pin is connected to the inductor and bootstrap capacitor.

4

GND

Ground pin

5

FB

Feedback pin. This pin is connected to an external resistor divider to program the system output voltage. When the FB pin voltage exceeds 1.1V, the over voltage protection is triggered. When the FB pin voltage is below 0.3V, the oscillator frequency is lowered to realize short circuit protection.

6

COMP

Compensation pin. This pin is the output of the transconductance error amplifier and the input to the current comparator. This pin is used to compensate the control loop. Connect a series RC network from this pin to GND pin. In some cases, an additional capacitor from this pin to GND pin is required.

7

EN

Enable Input. EN is a digital input that turns the regulator on or off. Drive EN high to turn on the regulator, drive it low to turn off. Pull up with 100kΩ resistor for automatic startup.

8

SS

Soft-start control input pin. SS controls the soft start period. Connect a capacitor from SS to GND to set the soft-start period. A 0.1µF capacitor sets the soft-start period to 15ms. To disable the softstart feature, leave SS unconnected.

–

EP

Exposed pad. It should be connected to GND in PCB layout.

S

R

Q Q

INTERNAL

REGULATOR

OSCILLATOR

2

7

5

4

3

1

VA

BS

SW

GND

EA

6

COMPFB

EN

IN

COMPARATOR

8

SS

CURRENT

SENSE

AMPLIFIER

CLK

SLOP COMP

PWM

COMPARATOR

1.1V

+

SCP

VA VB

VB

5µA

180K/500K

0.

925V

2.5V

M1

M2

0.3V

COMPARATOR

1.5V

SHUTDOWN

LOCK

Pin Descriptions

Functional Block Diagram

AP3513E

Document number: DS36692 Rev. 2 - 2

3 of 11

www.diodes.com

January 2014

AP3513E

A Product Line of

Diodes Incorporated

NE W P R OD UC T

Symbol

Parameter

Rating

Unit

VIN

IN Pin Voltage

-0.3 to 20

V

VEN

EN Pin Voltage

-0.3 to VIN

V

VSW

SW Pin Voltage

21

V

VBS

BS Pin Voltage

-0.3 to VSW+6

V

VFB

FB Pin Voltage

-0.3 to 6

V

COMP

COMP Pin Voltage

-0.3 to 6

V

VSS

SS Pin Voltage

-0.3 to 6

V

TJ

Operating Junction Temperature

+150

ºC

T

STG

Storage Temperature

-65 to +150

ºC

T

LEAD

Lead Temperature (Soldering, 10sec)

+260

ºC

θ

JA

Thermal Resistance (Junction to Ambient)

SO-8EP

60

o

C/W

V

HBM

ESD (Human Body Model)

2000

V

VMM

ESD (Machine Model)

200

V

Symbol

Parameter

Min

Max

Unit

VIN

Input Voltage

4.5

18

V

TA

Operating Ambient Temperature

-40

+85

ºC

Absolute Maximum Ratings (Note 4)

Note 4: 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 Condi tions” is not implied. Exposure to “Absolute Maximum Ratings” for extended periods may affect device reliability.

Recommended Operating Conditions

AP3513E

Document number: DS36692 Rev. 2 - 2

4 of 11

www.diodes.com

January 2014

AP3513E

A Product Line of

Diodes Incorporated

NE W P R OD UC T

Symbol

Parameter

Conditions

Min

Typ

Max

Unit

SUPPLY VOLTAGE (IN PIN)

VIN

Input Voltage

–

4.5 – 18

V

IQ

Quiescent Current

V

FB

= 1V, V

EN

= 3.3V

–

1.2

1.4

mA

I

SHDN

Shutdown Supply Current

V

EN

= 0V

–

0.1

1.0

µA

UNDER VOLTAGE LOCKOUT

V

UVLO

Input UVLO Threshold

VIN Rising

3.65

4.0

4.25

V

HYS

Input UVLO Hysteresis

– – 0.2 – V

ENABLE (EN PIN)

–

EN Shutdown Threshold Voltage

–

1.1

1.5 2 V

–

EN Shutdown Threshold Voltage Hysteresis (Note 5)

–

350 – mV

–

EN Lockout Threshold Voltage

–

2.2

2.5

2.7 V –

EN Lockout Hysteresis

–

210 – mV

VOLTAGE REFERENCE (FB PIN)

VFB

Feedback Voltage

–

0.907

0.925

0.943

V

FBOV

Feedback Over Voltage Threshold

– – 1.1 – V

IFB

Feedback Bias Current

V

FB

= 1V

-0.1 – 0.1

µA

MOSFET

R

DSONH

High-side Switch On-resistance (Note 6)

I

SW

= 0.2A&0.7A

–

100 – mΩ

R

DSONL

Low-side Switch On-resistance (Note 6)

I

SW

= -0.2A&-0.7A

–

100 – mΩ

CURRENT LIMIT

I

LEAKH

High-side Switch Leakage Current

V

IN

= 18V, V

EN

= 0V, V

SW

= 0V

–

0.1

10

μA

I

LIMH

High-side Switch Current Limit

–

4.3

5.6 – A

I

LIML

Low-side Switch Current Limit

From drain to source

–

50 – mA

SWITCHING REGULATOR

f

OSC1

Oscillator Frequency

–

410

500

590

kHz

f

OSC2

Short Circuit Oscillator Frequency

– – 180 – kHz

D

MAX

Max. Duty Cycle

V

FB

= 0.85V

–

90 – %

D

MIN

Min. Duty Cycle

V

FB

= 1V

– – 0

%

Electrical Characteristics (V

= V

= 12V, V

IN

EN

OUT

= 3.3V, T

= +25ºC, unless otherwise specified.)

A