Diodes AP6502A User Manual

A

C

Y

%

240kHz 23V 2A SYNCHRONOUS DC/DC BUCK CONVERTER

high

Pin Assignments

(T op View)

1

BS

IN

2 3

SW

GND

4

SO-8EP

Figure 1. Package Pin Out

Applications

• Gaming Consoles

• Flat Screen TV Sets and Monitors

• Set Top Boxes

• Distributed Power Systems

• Home Audio

• Consumer Electronics

• Network Systems

• FPGA, DSP and ASIC Supplies

• Green Electronics

8 7 6 5

Description

The AP6502A is a 240kHz switching frequency external compensated synchronous DCDC buck converter. It has integrated low R and low side MOSFETs.

The AP6502A enables continues load current of up to 2A with efficiency as high as 95%.

The AP6502A features current mode control operation, which enables fast transient response times and easy loop stabilization.

The AP6502A simplifies board layout and reduces space requirements with its high level of integration and minimal need for external components, making it ideal for distributed power architectures.

The AP6502A is available in a standard Green SO-8EP package with exposed PAD for improved thermal performance and is RoHS compliant.

Features

NEW PRODUCT

• VIN 4.75V to 23V

• 2A Continuous Output Current, 3A Peak

• V

• 240kHz Switching Frequency

• Programmable Soft-Start

• Enable Pin

• Protection

• Totally Lead-Free & Fully RoHS Compliant (Notes 1 & 2)

• Halogen and Antimony Free. “Green” Device (Note 3)

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 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

Adjustable to 0.925 to 16V

OUT

 OCP  Thermal Shutdown

.

DSON

Typical Applications Circuit

100

P6502A

SS EN

COMP FB

90

V = 5V

IN

V = 12V

80

) (

70

IEN

EFFI

60

50

V = 3.3V

OUT

L = 10µH

40

0 0.4 0.8 1.2 1.6 2

LOAD CURRENT (A)

Efficie ncy vs. Load Cu rre nt

AP6502A

Document number: DS35812 Rev. 3 - 2

IN

Figure 2. Typical Application Circuit

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Pin Descriptions

NEW PRODUCT

Number

1 BS

2 IN

3 SW

4 GND Ground (Connect the exposed pad to Pin 4). 5 FB

6 COMP

7 EN

8 SS

EP EP EP exposed thermal pad connect to Pin 4 GND

Name

Functional Block Diagram

P6502A

Function

High-Side Gate Drive Boost Input. BS supplies the drive for the high-side N-Channel MOSFET switch. Connect a 0.01µF or greater capacitor from SW to BS to power the high side switch.

Power Input. IN supplies the power to the IC, as well as the step-down converter switches. Drive IN with a

4.75V to 23V power source. Bypass IN to GND with a suitably large capacitor to eliminate noise on the input to the IC. See Input Capacitor.

Power Switching Output. SW is the switching node that supplies power to the output. Connect the output LC filter from SW to the output load. Note that a capacitor is required from SW to BS to power the high-side switch.

Feedback Input. FB senses the output voltage and regulates it. Drive FB with a resistive voltage divider connected to it from the output voltage. The feedback threshold is 0.925V. See Setting the Output Voltage.

Compensation Node. COMP is used to compensate the regulation control loop. Connect a series RC network from COMP to GND. In some cases, an additional capacitor from COMP to GND is required. See Compensation Components.

Enable Input. EN is a digital input that turns the regulator on or off. Drive EN high to turn on the regulator; low to turn it off. Attach to IN with a 100k pull up resistor for automatic startup.

Soft-Start Control Input. SS controls the soft-start period. Connect a capacitor from SS to GND to set the softstart period. A 0.1µF capacitor sets the soft-start period to 15ms. To disable the soft-start feature, leave SS floating.

AP6502A

Document number: DS35812 Rev. 3 - 2

Figure 3. Functional Block Diagram

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Absolute Maximum Ratings (Note 4) (@T

Symbol Parameter Rating Unit

VIN

VSW

VBS VFB

VEN

V

COMP

TST

TJ TL

ESD Susceptibility (Note 5)

HBM Human Body Model 3 kV

MM Machine Model 250 V

Notes: 4. Stresses greater than the 'Absolute Maximum Ratings' specified above may cause permanent damage to the device. These are stress ratings only;

NEW PRODUCT

functional operation of the device at these or any other conditions exceeding those indicated in this specification is not implied. Device reliability may be affected by exposure to absolute maximum rating conditions for extended periods of time.

5. Semiconductor devices are ESD sensitive and may be damaged by exposure to ESD events. Suitable ESD precautions should be taken when handling and transporting these devices.

Supply Voltage Switch Node Voltage Bootstrap Voltage Feedback Voltage -0.3V to +6 V Enable/UVLO Voltage -0.3V to +6 V Comp Voltage -0.3V to +6 V Storage Temperature -65 to +150 °C Junction Temperature +150 °C Lead Temperature +260 °C

= +25°C, unless otherwise specified.)

A

-0.3 to +26

-1.0 to V

V

-0.3 to VSW +6

SW

IN

+0.3

Thermal Resistance (Note 6)

Symbol Parameter Rating Unit



JA



JC

Note: 6. Test condition: SO-8EP: Device mounted on 1" x 1" FR-4 substrate PC board, 2oz copper, with minimum recommended pad on top layer and thermal vias to bottom layer ground plane.

Recommended Operating Conditions (Note 7) (@T

Symbol Parameter Min Max Unit

VIN

TA

Note: 7. The device function is not guaranteed outside of the recommended operating conditions.

AP6502A

Document number: DS35812 Rev. 3 - 2

Junction to Ambient SO-8EP 74

Junction to Case SO-8EP 16

= +25°C, unless otherwise specified.)

A

Supply Voltage Operating Ambient Temperature Range

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4.75

-40

23 V

+85 °C

P6502A

V V V

°C/W

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Electrical Characteristics (V

Symbol Parameter Test Conditions Min Typ Max Unit

Shutdown Supply Current Supply Current (Quiescent) High-Side Switch On-Resistance (Note 8) 130 m Low-Side Switch On-Resistance (Note 8) 130 m HS Current Limit Minimum duty cycle 4.4 A LS Current Limit From Drain to Source 0.9 A

R

DS(ON)1

R

DS(ON)2

I

LIMIT

I

LIMIT

IIN IIN

High-Side Switch Leakage Current

AVEA Error Amplifier Voltage Gain

(Note 8)

NEW PRODUCT

GEA GCS

FSW

FFB

D

MAX

TON

VFB

Error Amplifier Transconductance COMP to Current Sense

Transconductance Oscillator Frequency Fold-back Frequency Maximum Duty Cycle Minimum On Time 130 ns Feedback Voltage

Feedback Overvoltage Threshold 1.1 V

V

EN_RISING

EN Rising Threshold 0.7 0.8 0.9 V EN Lockout Threshold Voltage 2.2 2.5 2.7 V EN Lockout Hysteresis 220 mV

INUV INUV

V

VTH

VIN Under Voltage Threshold Hysteresis

HYS

Under Voltage Threshold Rising

IN

Soft-Start Current Soft-Start Period

TSD

Note: 8. Guaranteed by design.

Thermal Shutdown (Note 6) 160 °C

AP6502A

Document number: DS35812 Rev. 3 - 2

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

IN

VEN = 0V VEN = 2.0V, VFB = 1.0V

V

= 0V, VSW = 0V,

EN

= 12V

V

SW

800 V/V I

= ±10µA

C

2.8 A/V V

= 0.75V

FB

V

= 0V

FB

VFB = 800mV

TA = -40°C to +85°C

3.80 4.05 4.40 V 250 mV V

= 0V

SS

= 0.1µF

C

SS

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P6502A

0.3 3.0 µA

0.6 1.5 mA

0 10 A

1000 µA/V

210 240 260 kHz

0.30 90 %

900 925 950 mV

6 A 15 ms

fSW

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C

O

TAG

5

Typical Performance Graphs (V

0.6

= 12V, V

IN

= 3.3V, TA = +25°C, unless otherwise specified.)

OUT

0.074

P6502A

0.58

0.56

0.54

0.52

0.5

QUIESCENT SUPPLY CURRENT (mA)

0.48 0 5 10 15 20

NEW PRODUCT

Quiescent Supply Current vs. Input Voltage

6.2

6

5.8

5.6

5.4

5.2

CURRENT LIMIT (A)

5

4.8

-60 -40 -20 0 20 40 60 80 100

0.92

0.918

0.916

E (V)

0.914

0.912

L

0.91

K V

0.908

0.906

FEEDBA

0.904

0.902

0.9

-60 -40 -20 0 20 40 60 80 100

AP6502A

Document number: DS35812 Rev. 3 - 2

INPUT VOLTAGE (V)

TEMPERATURE (C)

Current Limit vs. Tempera t ur e

TEMPERATURE (°C)

Feedback Voltage vs. Temperatu r e

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0.064

0.054

0.044

0.034

0.024

0.014

SHUTDOWN SUPPLY CURRENT (µA)

0.004 0 5 10 15 20

Shu tdown Su pply Curr e nt v s . Input Vol tage

3.33

3.329

3.328

3.327

3.326

3.325

3.324

3.323

OUTPUT VOLTAGE (V)

3.322

3.321

3.32 4101520

25

250

245

240

235

OSCILLAT OR FREQUENCY (Khz)

230

225

-60 -40 -20 0 20 40 60

INPUT VOLTAGE (V)

V = 12V

IN

INPUT VOLTAGE (V)

Line Regulation

TEMPERATURE (°C)

Oscillator Frequency vs. Temperature

100

80

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