Diodes AP5004 User Manual

AP5004

PWM CONTROL 2.5A STEP-DOWN CONVERTER

Description

The AP5004 is a step-down switching regulator with PWM
control and includes a reference voltage source, oscillation
circuit, error amplifier, and an internal NMOS.

AP5004 provides low-ripple power, high efficiency, and
excellent transient characteristics. The PWM control circuit is
able to vary the duty ratio linearly from 0% up to 90%. An
enable function, an over-current protect function, and a short
circuit protect function are built inside, and when OCP or SCP
happens, the operation frequency will be reduced from
300 KHz to 50 KHz. Also, an internal compensation block has
been designed in to minimize the external component count.

With built-in power NMOS, a step-down switching regulator
can easily be built by adding a coil, capacitors, and a diode.

The combination of high efficiency, low standby current, high
input voltage (32V), and high output current (2.5A)in a small
SOP-8L package gives the AP5004 an unprecedented
advantage in any high power system applications.

Pin Assignments

(Top View )

1

EN

2

FB

Vboost

AP5004

3

Output

SOP-8L

Applications

• Microprocessor Core Supply

• Networking Power Supply

• LCD MNT, TV Power Supp l y

• Telecom Power Supply

8

GND

7

GND

6

Vcc

54

Vcc

Features

• Input Voltage: 10V to 32V

• Adjustable Output Voltage from 0.8V to 6V

• Duty Ratio: 0% to 90% PWM control

• Oscillation Frequency: 300KHz typical

• Short Circuit Protect Frequency:50 KHz

• 2uA Maximum Standby Current

• Current Limit, Enable Function

• Thermal Shutdown Function

• Built-in Internal SW N-channel MOS

• SOP-8L: Available in “Green” Molding Compound

(No Br, Sb)

• Lead Free Finish/ RoHS Compliant (Note 1)

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

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

AP5004

Document number: DS31444 Rev. 5 - 2

1 of 11

www.diodes.com

August 2010

© Diodes Incorporated

Typical Application Circuit

AP5004

PWM CONTROL 2.5A STEP-DOWN CONVERTER

C7 0.1uF

U1

VIN

C2

220uF/63V

Notes: 2. Suggested DIODES Power Schottky P/N: PDS540 or B540C.

C3

0.1uF

R5
100K

C6

0.1uF

3

5

6

1

Vboost

VCC

VCC

EN

Note : V

R

AP5004

OUT

4

Output

2

FB

7

GND

8

GND

x (1+R1/R2)

= V

FB

= 100 ~ 300 ohm

B

L1-(WURTH 744132)
33uH

2

1

R1

685ohm

D1
B340

R2

130ohm

C1

100pF

C4

470uF/16V

VOUT = 5V

C5

0.1uF

Pin Descriptions

Pin Name Pin # Description

EN 1
FB 2 Feedback pin

V

3 High-side gate driver boost pin

boost

Output 4 Switch output pin

VCC

GND

5、6
7、8

H: Normal operation
L: Step-down operation stopped

VCC
GND pin

AP5004

Document number: DS31444 Rev. 5 - 2

2 of 11

www.diodes.com

August 2010

© Diodes Incorporated

Functional Block Diagram

AP5004

PWM CONTROL 2.5A STEP-DOWN CONVERTER

Output

Vcc

Driver

Oscillation

Circuit

PWM -Switched

Control Circuit

Reference Voltage

+

-

FB

VL

Thermal

Shutdown

Vboost

V

EN

GNDEN

Absolute Maximum Ratings

Symbol Parameter Rating Unit

ESD HBM Human Body Model ESD Protection 1.8 KV

ESD MM Machine Model ESD Protection 550 V

VCC VCC Pin Voltage VSS - 0.3 to VSS + 35 V
VFB V
VEN EN Pin Voltage VSS - 0.3 to V

V

V

boost

V

Switch Pin Voltage VSS - 0.3 to V

OUTPUT

TJ Operating Junction Temperature Range -10 to +125

T

Storage Temperature Range -40 to +150

ST

Caution: The absolute maximum ratings are rated values exceeding which the product could suffer physical damage. These values must

therefore not be exceeded under any conditions.

Pin Voltage VSS - 0.3 to VCC V

OUT

+ 0.3 V

CC

Pin Voltage V

boost

+ 7V V

OUTPUT

+ 0.3 V

CC

o

C

o

C

Recommended Operating Conditions

Symbol Parameter Min Max Unit

VIN Input Voltage 10 32 V

I

Output Current 0 2.5 A

OUT

TA Operating Ambient Temperature -10 85

AP5004

Document number: DS31444 Rev. 5 - 2

3 of 11

www.diodes.com

August 2010

© Diodes Incorporated

o

C

AP5004

)

PWM CONTROL 2.5A STEP-DOWN CONVERTER

Electrical Characteristics (V

Symbol Parameter Conditions Min Typ. Max Unit

VFB Feedback Voltage 0.780 0.8 0.820 V

VIN Input Voltage 10 - 32 V

I

Standby Current VEN =0V - 2 - µA

STBY

∆V

OUT/VOUT

∆V

OUT/VOUT

f

OSC

f

OSC1

DC

VIH
VIL
ISH

R

DS(ON)

I

LIMIT

θ

θ

Notes: 3. Test condition for SOP-8L: Device mounted on 2oz copper, minimum recommended pad layout, FR-4 PCB.

Line Regulation V
Load Regulation I

Oscillation Frequency Measure waveform at SW pin 240 300 360 KHz

Frequency of Current Limit or
Short Circuit Protect

Maximum Duty Cycle V
Minimum Duty Cycle VFB =1.0V - 0 - %
EN Pin Logic Input Threshold
Voltage

ISL

η

JA

JC

EN Pin Input Leakage Current
Internal MOSFET R

Current Limit 3.5 - - A
Efficiency V

Thermal Resistance Junction­to-Ambient
Thermal Resistance Junction­to-Case

= 12V, TA=25°C, unless otherwise specified)

IN

= 10V~32V -

IN

= 0.1 to 2.5A - 1 1.5 %

OUT

±1.0 ±1.5

Measure waveform at SW pin - 50 - KHz

=0.5V - 90 - %

FB

Regulator ON 2.0 - ­Regulator OFF - - 0.8

- 20 - µA

- -10 - µA

- 80 120 mΩ

DS(ON

= 12V, V

IN

OUT

= 5V, I

= 2.5A - 90 - %

OUT

SOP-8L (Note 3) - 124 ­SOP-8L (Note 3) - 25 -

%/V

o

C/W

o

C/W

V

AP5004

Document number: DS31444 Rev. 5 - 2

4 of 11

www.diodes.com

August 2010

© Diodes Incorporated