Diodes AP3417C User Manual

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Description

The AP3417C is a high efficiency step-down DC-DC voltage

converter. The chip operation is optimized by peak-current mode

architecture with built-in synchronous power MOSFET switchers. The

oscillator and timing capacitors are all built-in providing an internal

switching frequency of 1.5MHz that allows the use of small surface

mount inductors and capacitors for portable product implementations.

Integrated Soft Start (SS), Under Voltage Lock Out (UVLO), Thermal

Shutdown Detection (TSD) and Short Circuit Protection are designed

to provide reliable product applications.

The device is available in adjustable output voltage version ranging

from 0.6V to 0.9×V

and is able to deliver up to 1A. It is also available in fixed voltage

versions of 1.2V, 1.8V and 3.3V without external feedback resistance.

The AP3417C is available in SOT-23-5 and DFN-2×2-6 packages.

PRELIMINARY DATASHEET

Features

 High Efficiency Buck Power Converter

 Wide Input Voltage Range: 2.5V to 5.5V

 Adjustable Output Voltage: 0.6V to 0.9×V

 Low R

 Built-in Power Switches for Synchronous Rectification with High

 Output Current: 1.0A

 Feedback Voltage: 600mV

 1.5MHz Constant Frequency Operation

 Thermal Shutdown Protection

 Low Dropout Operation at 100% Duty Cycle

 No Schottky Diode Required

 Input Over Voltage Protection

 Output Over Voltage Protection

 Over Current Protection

DS(ON)

Efficiency

when input voltage range is from 2.5V to 5.5V,

IN

Internal Switches:200m (V

= 5V)

IN

Product Line o

Diodes Incorporated

P3417C

1.5MHZ SYNCHRONOUS STEP-DOWN DC-DC CONVERTER

Pin Assignments

K Package DN Package

(SOT-23-5) (DFN-2×2-6)

EN

1

GND

2

34

LX

FB

5

VIN

Applications

 Post DC-DC Voltage Regulation

 PDA and Notebook Computer

Typical Applications Circuit

AP3417C

Document number: DS36516 Rev. 1 - 0

For ADJ Version

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Typical Applications Circuit (cont.)

V

(V)

OUT

PRELIMINARY DATASHEET

3.3 450 100 2.2

2.5 320 100 2.2

1.8 200 100 2.2

1.2 100 100 2.2

1.0 66 100 2.2

Product Line o

Diodes Incorporated

AP3417C

For Fixed Versions

Component Guide

R1 (kΩ) R2 (kΩ) L (µH)

P3417C

Pin Descriptions

Pin Number

SOT-23-5 DFN-2×2-6

1 2 EN Chip enable pin. Active high

2 5 GND Ground pin

3 4 LX Switch output pin

4 3 VIN Power supply

5 6 FB Feedback voltage of output

1 NC No internal connection

Pin Name Function

AP3417C

Document number: DS36516 Rev. 1 - 0

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Functional Block Diagram

EN

Product Line o

Diodes Incorporated

P3417C

VIN

1(2)

Generator

Bias

Generator

Soft

Start

FB

5(6)

PRELIMINARY DATASHEET

Bandgap

Reference

A(B) A for SOT-23-5 B for DFN-2×2-6

Absolute Maximum Ratings (Note 1)

Saw-tooth

-

+

Amplifier

-

+

Error

Over Voltage

Oscillator

+

-

Modulator

Comparator

Over -Current

Comparator

Control

Logic

Reverse Inductor

Current Comparator

IOVP Comparator

Current

Sensing

Buffer &

Dead Time

Control

Logic

4(3)

3(4)

LX

-

+

-

+

2(5)

GND

Symbol Parameter Rating Unit

VIN

VEN

ILX

PD Power Dissipation (On PCB, TA = +25°C)

θJA

θJC

TJ

T

STG

TOP

VMM

V

HBM

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.

Input Voltage for the MOSFET Switch 0 to 6.0 V

Enable Input Voltage

LX Pin Switch Current 1.8 A

Thermal Resistance (Junction to Ambient, Simulation)

Thermal Resistance (Junction to Case, Simulation) SOT-23-5 130 °C/W

Operating Junction Temperature 155

Storage Temperature -55 to +150

Operating Temperature -40 to +85

ESD (Machine Model) 200 V

ESD (Human Body Model) 2000 V

-0.3 to V

SOT-23-5 0.4

DFN-2×2-6 1.89

SOT-23-5 250

DFN-2×2-6 53

IN

+0.3

V

W

°C/W

°C

AP3417C

Document number: DS36516 Rev. 1 - 0

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Recommended Operating Conditions

Symbol Parameter Min Max Unit

VIN

TA

TJ

Supply Input Voltage 2.5 5.5 V

Operating Ambient Temperature -40 85 ºC

Operating Junction Temperature -40 125 ºC

Electrical Characteristics (@V

otherwise specified.)

Symbol Parameters Conditions Min Typ Max Unit

VIN

I

OFF

ION

VFB

Input Voltage Range 2.5 5.5 V

Shutdown Current

Active Current

Regulated Feedback Voltage

= V

IN

PRELIMINARY DATASHEET

V

OUT

V

OUT/VOUT

R

DS(ON)P

R

DS(ON)N

V

D

V

IPK

f

OSC

PMOSFET R

NMOSFET R

EN_H

EN_L

IEN

tSS

MAX

UVLO

TSD

AP3417C

Document number: DS36516 Rev. 1 - 0

Output Voltage

Regulated Output Voltage Accuracy

Peak Inductor Current 1.5 1.9 A

Oscillator Frequency

DS(ON)

EN High Level Input Voltage 1.5 V

EN Low Level Input Voltage 0.4 V

EN Input Current 0.1 µA

Soft Start Time 400 µs

Maximum Duty Cycle 100 %

Under Voltage Lock Out Threshold

Thermal Shutdown Hysteresis = 30°C 155 160 °C

= 5V, V

EN

V

= 1.2V, V

OUT

V

EN

V

FB

For Adjustable Output Voltage

Fixed Output 1.2V 1.176 1.2 1.224

Fixed Output 1.8V 1.764 1.8 1.836

Fixed Output 3.3V 3.234 3.3 3.366

V

IN

I

OUT

V

IN

Rising 2.3

Falling 2.1

Hysteresis 0.2

FB

= 0

= 0.55V

= 2.5V to 5.5V,

= 0 to 1.0A

= 2.5V to 5.5V

= 5V

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= 0.6V, L = 2.2µH, C

0.588 0.6 0.612 V

Product Line o

P3417C

= 4.7µF, C

IN

0.1 µA

220 µA

-3 3 %

1.2 1.5 1.8 MHz

200

= 10µF, TA = +25°C, unless

OUT

September 2013

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m

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