Diodes AP1506 User Manual

AP1506

150KHz, 3A PWM BUCK DC/DC CONVERTER

Description

The AP1506 series are monolithic IC designed for a step­down DC/DC converter, and own the ability of driving a 3A
load without external transistor. Due to reducing the number
of external components, the board space can be saved easily.
The external shutdown function can be controlled by logic
level and then come into standby mode. The internal
compensation makes feedback control have good line and
load regulation without external design. Regarding protected
function, thermal shutdown is to prevent over temperature
operating from damage, and current limit is to prevent over
current operating of the output switch. If current limit function
occurred and V
frequency will be reduced. The AP1506 series operate at a
switching frequency of 150KHz thus allowing smaller sized
filter components than what would be needed with lower
frequency switching regulators. Other features include a
guaranteed +
input voltage and output load conditions, and +
oscillator frequency. The output version included fixe d 3.3V,
5V, 12V, and an adjustable type. The packages are available
in a standard 5-lead TO263 and TO220.

is down to 0.5V below, the switching

FB

4% tolerance on output voltage under specified

15% on the

Pin Assignments

( Top View )

Metal Tab GND

TO263-5L

( Top View )

TO220-5L/TO220-5L(R)

5 SD
4 FB
3 Gnd
2 Output

1 V

IN

5 SD
4 FB
3 Gnd
2 Output
1 V

IN

Features

Applications

• Output Voltage: 3.3V, 5V, 12V and Adjustable Output
Version

• Adjustable Version Output Voltage Range, 1.23V to
18V+4%

• 150KHz +15% Fixed Switching Frequency

• Voltage Mode Non-Synchronous PWM Control

• Thermal-Shutdown and Current-Limit Protection

• ON/OFF Shutdown Control Input

• Operating Voltage can be up to 22V

• Output Load Current: 3A

• Lead Free packages: TO263-5L and TO220-5L(R)

• TO263-5L and TO220-5L(R): Available in “Green”
Molding Compound (No Br, Sb)

• Low Power standby mode

• Built-in Switching Transistor On Chip

• 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

.

• Simple High-Efficiency Step-Down Regulator

• On-Card Switching Regulators

• Positive to Negative Converter

AP1506

Document number: DS31015 Rev. 7 - 2

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×

Typical Application Circuit

(1) Fixed Type Circuit

AP1506

150KHz, 3A PWM BUCK DC/DC CONVERTER

12V

DC Input

C

IN

Capacitor

(2) Adjustable Type Circuit

12V

DC Input

C

IN

Capacitor

(3) Delay Start Circuit

FB

4

AP1506

1

V

IN

R2

V

IN

-33

5

SD

12

AP1506

SD

V

out

V

FB

2

3

GND

FB

4

35

= V

FB

= 1.23V

GND

R2 = 1K ~ 3K

R2

Output

Output

(1 +

Schottky Diode

R1

Schottky Diode

R1

)

R2

R1

33

Inductor

D1*

D1*

L1

uH

L1

47uH

3.3V/3A

Output Load

Co

Capacitor

5V/ 3A

Output Load

Co

Capacitor

FB

12V

DC Input

C

IN

Capacitor

V

C

DELAY

0.1uF

4

Output

AP1506

1

IN

5

SD

R

DELAY

2

3

GND

Schottky Diode

L1

47uH

D1*

5V / 3A

Output Load

Co

Capacitor

10K

Notes: 2. For up to 2A = DFLS230L (Vf = 0.42V)

For up to 3A = B340LA, B340LB (V

= 0.45V)

f

AP1506

Document number: DS31015 Rev. 7 - 2

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Pin Descriptions

Pin Name Description

VIN Operating Voltage Input

Output Switching Output

GND Ground

FB Output Voltage Feedback Control
SD ON/OFF Shutdown

Functional Block Diagram

AP1506

150KHz, 3A PWM BUCK DC/DC CONVERTER

SD

FB

Current

Source

bias

1.235V

Reference

+

Amp

-

2.5V

Regulator

Frequecy

compen-

sation

Start

up

-

Comp
+

150KHz

OSC.

200mV

Comp

Comp

Pre-driver

Thermal

Shutdown

V

IN

220mV

+

-

-

+

3A

Switch

Output

GND

AP1506

Document number: DS31015 Rev. 7 - 2

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AP1506

150KHz, 3A PWM BUCK DC/DC CONVERTER

Absolute Maximum Ratings

Symbol Parameter Rating Unit

ESD MM Machine Model ESD Protection 400 V

VCC Supply Voltage +24 V
VSD ON/OFF Pin Input Voltage -0.3 to +18 V
VFB Feedback Pin Voltage -0.3 to +18 V

V

Output Voltage to Ground -1 V

OUT

PD Power Dissipation Internally Limited W

TST Storage Temperature -65 to +150

TOP Operating Junction Temperature -40 to +125

Recommended Operating Conditions

Symbol Parameter Min Max Unit

VOP Operating Voltage 4.5 22 V

TA Operating Ambient Temperature -20 85

o

C

o

C

o

C

AP1506

Document number: DS31015 Rev. 7 - 2

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AP1506

150KHz, 3A PWM BUCK DC/DC CONVERTER

Electrical Characteristics (All Output Voltage Versions)

Unless otherwise specified, V
Specifications with boldface type are for full operating temperature range, the other type are for T

= 12V for 3.3V, 5V, adjustable version and V

IN

Symbol Parameter Conditions Min Typ. Max Unit

V

= 1.3V

IFB Feedback Bias Current

F

Oscillator Frequency

OSC

F

SCP

V

DC

SAT

Oscillator Frequency of
Short Circuit Protect

Saturation Voltage

Max. Duty Cycle (ON) V
Min. Duty Cycle (OFF) V

FB

(Adjustable version only)

When current limit occurred
and V

I

OUT

< 0.5V, Ta = 25 oC

FB

= 3A

No outside circuit

= 0V force driver on

V

FB

= 0V force driver on - 100 -

FB

= 12V force driver off - 0 -

FB

Peak current

ICL Current Limit

Output
Leakage
Current

IL

Output = 0V
Output = -1V V

IQ Quiescent Current V

I

STBY

VIL
VIH High (regulator OFF) 2.0 -

IH

IL

θ

JA

Standby Quiescent
Current

ON/OFF Pin Logic Input
Threshold Voltage

ON/OFF Pin Logic
Input Current

ON/OFF Pin Input
Current

Thermal Resistance
Junction to Ambient

No outside circuit

= 0 force driver on

V

FB

No outside circuit

= 12 force driver off

V

FB

= 22V - -5 - mA

IN

= 12 force driver off - 5 10 mA

FB

ON/OFF pin = 5V

= 22V

V

IN

Low (regulator ON) -

V

= 2.5V (OFF) - - -0.01

LOGIC

V

= 0.5V (ON) - -0.1 -1

LOGIC

TO263-5L (Note 3) 37 ­TO220-5L(R) (Note 3) 31 -

= 18V for the 12V version. I

IN

= 25ºC.

J

- -10

LOAD

-50

-100

= 0.5A

127 150 173

110

-

173

10 30 50 KHz

1.6

- 1.4

1.7

5.5

3.6 4.5

6.5

- - -200

- 70

1.3

150

200

0.6

nA

KHz

V

%

A

µA

µA

V

µA

o

C/W

θ

JC

Notes: 3. Test condition: Device mounted with copper area of approximately 3 in2, no air flow.

Thermal Resistance
Junction to Case

AP1506

Document number: DS31015 Rev. 7 - 2

TO263-5L (Note 3) 6 ­TO220-5L(R) (Note 3) 5 -

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o

C/W

June 2010

© Diodes Incorporated