Diodes AP3417A User Manual

1A, 1.4MHz High Efficiency Synchronous DC-DC Buck Converter AP3417A

Data Sheet

General Description

The AP3417A is a 1.4MHz fixed frequency, current
mode, PWM synchronous buck (step-down) DC-DC
converter, capable of driving a 1A load with high
efficiency, excellent line and load regulation. The
device integrates synchronous P-channel and
N-channel power MOSFET switches with low
on-resistance. It is ideal for powering portable
equipment that runs from a single Li-ion battery.

A standard series of inductors are available from
several different manufacturers optimized for use
with the AP3417A. This feature greatly simplifies the
design of switch-mode power supplies.

The AP3417A is available in SOT-23-5 package.

Features

• Input Voltage Range: 2.5V to 5.5V

• Output Voltage: 0.6V to V

• ADJ Output

• Fixed 1.4MHz Frequency

• High Efficiency up to 95%

• Output Current: 1A

• Current Mode Control

• 100% Duty Cycle in Dropout

• Built-in Over Current Protection

• Built-in Short Circuit Protection

• Built-in Thermal Shutdown Protection

• Built-in UVLO Function

• Built-in Soft-start

IN

Applications

• Set-top Box

• Datacom

• Portable Device

• Smart Phone

Figure 1. Package Type of AP3417A

SOT-23-5

Aug. 2012 Rev. 1. 2 BCD Semiconductor Manufacturing Limited

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Data Sheet

1A, 1.4MHz High Efficiency Synchronous DC-DC Buck Converter AP3417A

Pin Configuration

K Package

(SOT-23-5)

EN

GND

SW

Figure 2. Pin Configuration of AP3417A (Top View)

1

2

34

5

FB

VIN

Pin Description

Pin Number Pin Name Function

Control input pin. Forcing this pin above 1.5V enables the IC.

1 EN

2 GND Ground pin

3 SW

4 VIN

5 FB

Forcing this pin below 0.4V shuts down the IC. When the IC is
in shutdown mode, all functions are disabled to decrease the
supply current below 1µA

Power switch output pin. Inductor connection to drain of the
internal PFET and NFET switches

Supply input pin. Bypass to GND with a 4.7µF or greater
ceramic capacitor

This is the feedback pin of the device. Connect this pin directly
to the output if the fixed output voltage version is used. For the
adjustable version, an external resistor divider is connected to
this pin

Aug. 2012 Rev. 1. 2 BCD Semiconductor Manufacturing Limited

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Data Sheet

1A, 1.4MHz High Efficiency Synchronous DC-DC Buck Converter AP3417A

Functional Block Diagram

DRIVER

Figure 3. Functional Block Diagram of AP3417A

Ordering Information

AP3417A -

G1: Green

Circuit Type

K: SOT-23-5

Package

SOT-23-5 -40 to 85 ºC AP3417AKTR-G1 G4H Tape & Reel

BCD Semiconductor's Pb-free products, as designated with "G1" suffix in the part number, are RoHS compliant
and green.

Temperature

Range

Part Number Marking ID Packing Type

TR: Tape & Reel

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Data Sheet

1A, 1.4MHz High Efficiency Synchronous DC-DC Buck Converter AP3417A

Absolute Maximum Ratings (Note 1)

Parameter Symbol Value Unit

Input Voltage VIN -0.3 to 6.0 V
Feedback Voltage VFB -0.3 to VIN +0.3 V
EN Pin Voltage VEN -0.3 to VIN+0.3 V
SW Pin Voltage VSW -0.3 to VIN+0.3 V
Thermal Resistance
Operating Junction Temperature TJ 150 ºC
Storage Temperature T
Lead Temperature (Soldering, 10sec) T
ESD(Machine Model) 200 V
ESD(Human Body Model) 2000 V

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.

θ

JA

-65 to 150 ºC

STG

260 ºC

LEAD

265 ºC/W

Recommended Operating Conditions

Parameter Symbol Min Max Unit

Input Voltage VIN 2.5 5.5 V
Operating Ambient Temperature TA -40 85 ºC

Aug. 2012 Rev. 1. 2 BCD Semiconductor Manufacturing Limited

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Data Sheet

1A, 1.4MHz High Efficiency Synchronous DC-DC Buck Converter AP3417A

Electrical Characteristics

VIN=5V, TA=25ºC, unless otherwise specified.

Parameters Symbol Conditions Min Typ Max Unit

Input Voltage VIN 2.5 5.5 V

Quiescent Current IQ V

Shutdown Supply Current I

Reference Voltage V

V

STBY

REF

V

I

FB_H

=0.65V 62 100

FB

=GND 0.1 1

EN

For Adjustable Output
Voltage

=1V -0.1 0.1

FB

Feedback Bias Current

I

V

FB_L

PMOSFET RON R

NMOSFET RON R

Switch Current Limit I

ISW = 200mA

DS(ON)_ P

ISW = -200mA

DS(ON) _N

LIM

V

1.5

H

=0V -0.1 0.1

FB

VFB=0.55V 1.3 1.8 A

EN Pin Threshold

VL 0.4

UVLO Threshold V

UVLO Hysteresis V

Oscillator Frequency F

Max. Duty Cycle D

Min. Duty Cycle D

VIN Rising 2.3

UVLO

0.2

HYS

1.12 1.40 1.68 MHz

OSC

100

MAX

0

MIN

µA

µA

0.588 0.6 0.612 V

µA

0.25

0.2

Ω

Ω

V

V

%

VSW =0V 0.1

I

SW Leakage Current

SW_H

I

VSW =5V 0.1

SW_L

µA

Soft-start Time tSS 1 ms

Thermal Shutdown T
Thermal Shutdown

Hysteresis

160 ºC

OTSD

T

20 ºC

HYS

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Data Sheet

1A, 1.4MHz High Efficiency Synchronous DC-DC Buck Converter AP3417A

Typical Performance Characteristics

=5V, TA=25ºC, unless otherwise specified.

V

IN

100

95

90

85

80

75

70

Efficiency (%)

65

60

55

50

2.5 3.0 3.5 4.0 4.5 5.0 5.5

Figure 4. Efficiency vs. Input Voltage Figure 5. Efficiency vs. Output Current

0.64

0.63

0.62

0.61

0.60

0.59

Reference Voltage (V)

0.58

0.57

0.56

-40 -20 0 20 40 60 80 100 120 140

Figure 6. Reference Voltage vs. Temperature Figure 7. Switch Current Limit vs. Temperature

Input Voltage (V)

Temperature (oC)

V

= 1.8V

OUT

I

= 1.0A

OUT

VIN = 5.0V

100

95

90

85

80

75

Efficiency (%)

70

65

60

0.0 0.2 0.4 0.6 0.8 1.0

Output Current (A)

VIN = 5.0V

=1.8V

V

OUT

2.4

2.3

2.2

2.1

2.0

1.9

1.8

1.7

Switch Current Limit (A)

1.6

1.5

1.4

-40 -20 0 20 40 60 80 100 120 140

Temperature (

VIN = 5.0V

o

C)

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Data Sheet

1A, 1.4MHz High Efficiency Synchronous DC-DC Buck Converter AP3417A

Typical Performance Characteristics (Continued)

VIN=5V, TA=25ºC, unless otherwise specified.

1.70

1.65

1.60

1.55

1.50

1.45

1.40

Frequency (MHz)

1.35

1.30

1.25

1.20

2.5 3.0 3.5 4.0 4.5 5.0 5.5

Input Voltage (V)

VIN = 5.0V

1.7

1.6

1.5

1.4

1.3

Frequency (MHz)

1.2

1.1

1.0

-40 -20 0 20 40 60 80 100 120 140

Temperature (oC)

VIN = VEN = 5.0V

Figure 8. Frequency vs. Input Voltage Figure 9. Frequency vs. Temperature

0.40

0.38

0.36

0.34

(Ω)

0.32

0.30

DS(ON)_UP

0.28

0.26

PMOS R

0.24

0.22

0.20

0.18

-40 -20 0 20 40 60 80 100 120 140

VIN = 5.0V
I

= 200mA

SW

Temperature (

o

C)

0.32

0.28

0.24

(Ω)

0.20

DS(ON)_DOWN

0.16

0.12

NMOS R

0.08

0.04

-40 -20 0 20 40 60 80 100 120 140

Temperature (

o

C)

VIN = 5.0V

= 200mA

I

SW

Figure 10. R

DS (ON)_UP

vs. Temperature Figure 11. R

DS (ON)_DOWN

vs. Temperature

Aug. 2012 Rev. 1. 2 BCD Semiconductor Manufacturing Limited

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m

Data Sheet

1A, 1.4MHz High Efficiency Synchronous DC-DC Buck Converter AP3417A

Typical Performance Characteristics (Continued)

VIN=5V, TA=25ºC, unless otherwise specified.

V

OUT_AC

V/div

10

V

SW

2V/div

IL

200mA/div

Figure 12. Output Ripple (I

Time 10ms/div

=0A) Figure 13. Output Ripple (I

OUT

V

OUT_AC

10mV/div

V

SW

2V/div

1A/div

I

L

Time 1µs/div

=1A)

OUT

V

V

EN

5V/div

V

OUT

1V/div

VSW

2V/div

I

1A/div

L

5V/div

V

OUT

1V/div

V

2V/div

1A/div

EN

SW

I

L

Time 200µs/div

Time 200µs/div

Figure 14. Enable Turn on (I

=1A) Figure 15. Enable Turn off (I

OUT

OUT

=1A)

Aug. 2012 Rev. 1. 2 BCD Semiconductor Manufacturing Limited

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Data Sheet

1A, 1.4MHz High Efficiency Synchronous DC-DC Buck Converter AP3417A

Typical Performance Characteristics (Continued)

VIN=5V, TA=25ºC, unless otherwise specified.

V

OUT

1V/div

VSW

5V/div

I

1A/div

L

Figure 16. Short Circuit Protection Figure 17. Short Circuit Protection Recovery

Time 10ms/div

(I

OUT

V

OUT

1V/div

V

SW

5V/div

=1A) (I

1A/div

I

L

Time 10ms/div

OUT

=1A)

Aug. 2012 Rev. 1. 2 BCD Semiconductor Manufacturing Limited

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Data Sheet

1A, 1.4MHz High Efficiency Synchronous DC-DC Buck Converter AP3417A

T ypical Application

Figure 18. Typical Application of AP3417A

Aug. 2012 Rev. 1. 2 BCD Semiconductor Manufacturing Limited

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Data Sheet

1A, 1.4MHz High Efficiency Synchronous DC-DC Buck Converter AP3417A

Mechanical Dimensions

SOT-23-5 Unit: mm(inch)

2.820(0.111)

0.100(0.004)

0.200(0.008)

0°

8°

0.950(0.037)

Y

T

P

3.020(0.119)

1.800(0.071)

2.000(0.079)

0.300(0.012)

0.400(0.016)

0.200(0.008)

0

.

0

(

0

0

7

.

R

E

F

0

8

2

)

0

0

.

0

1

.

0

0

(

0

0

9

.

0

(

0

0

3

.

1

0

0

.

0

0

0

(

)

0

0

.

0

(

0

5

0

)

6

3

0

.

)

5

.

)

1

5

0

Aug. 2012 Rev. 1. 2 BCD Semiconductor Manufacturing Limited

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BCD Semiconductor Manufacturing Limited

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