Diodes PAM2327 User Manual

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Description

The PAM2327 is a 3.5A step-down synchronous converter. The

1.2MHz switching frequency enables the use of small external components. The ultra-small 2mm x 2mm footprint and high efficiency make the PAM2327 an ideal choice for portable applications.

The PAM2327 delivers 3.5A maximum output current while consuming only 55µA no load quiescent current. Low R integrated MOSFETs and 100% duty cycle operation make the PAM2327 the ideal choice for high output voltage, high current applications which require a low dropout threshold.

The PAM2327 provides excel lent transient response and output accuracy across the operating range.

The PAM2327 maintains high efficiency throughout the load range.

The PAM2327 automatically optimizes efficiency during light load mode (PSM) and maintains constant frequency and low output ripple during PWM mode.

Over-temperature and short circuit protection safeguard the PAM2327 and system components from damage.

The PAM2327 is available in an ultra-small QFN2x2-12 package. The product is rated over a temperature range of -40°C to +85°C.

Applications

 Cellular Phone  Digital Cameras  Hard Disk Drives  MP3 Players  PDAs and Handheld Computers  Portable Media Players  USB Devices  Wireless Network Cards

Typical Applications Circuit

A Product Line o

Diodes Incorporated

PAM2327

FAST TRANSIENT 3.5A STEP-DOWN CONVERTER

Pin Assignments

Features

 3.5A Maximum Output Current  Tiny 1.0µH Chip Inductor  Excellent Transient Response  Input Voltage: 2.5V to 5.5V  Adjustable Output Voltage: 1.0V to 4.0V  High Efficiency with 1.2MHz Switching Frequency  55µA No Load Quiescent Current  100% Duty Cycle Low-Dropout Operation  Internal Soft Start  Power Good Indicator  Over-Temperature and Current Limit Protection  Hiccup mode for output short protection  1µA Shutdown Current  -40°C to +85°C Temperature Range  Available in QFN2x2-12 Package  RoHS/REACH Compliant

PAM2327

Document number: DS36277 Rev. 2 - 2

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Pin Descriptions

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PAM2327

Number

1 PVIN Supply Voltage to power FETs. PVIN is connected to VIN internally. 2, 11 SW Switch Output. Pin 2 and 11 can be connected together. 3, 12 PGND Power Ground. Pin 3 and 12 can be connected together.

4 AGND Quiet ground for controller circuits

5 NC Leave this pin open. Do not connect it to ground.

6 OUT Input sense pin for output voltage

7 FB Feedback. An external resistor divider from the output to GND, tapped to the FB pin, sets the output voltage.

8 EN On/Off Control.

9 PG

10 VIN Supply Voltage to internal control circuitry. VIN is connected to PVIN internally.

Name

Function

Power Good Indicator. The output of this pin is an open drain with internal pull up resistor to VIN. PG is pulled up to VIN when the FB voltage is within 10% of the regulation level, otherwise it is LOW.

Functional Block Diagram

Absolute Maximum Ratings (@T

These are stress ratings only and functional operation is not implied. Exposure to absolute maximum ratings for prolonged time periods may affect device reliability. All voltages are with respect to ground.

Parameter Rating Unit

Input Voltage -0.3 to +6.5 V EN, FB Pin Voltage

SW Pin Voltage Junction Temperature 150 °C

Storage Temperature Range -65 to +150 °C Soldering Temperature 300, 5sec °C

PAM2327

Document number: DS36277 Rev. 2 - 2

= +25°C, unless otherwise specified.)

A

-0.3 to V

-0.3 to (V

IN

+0.3)

IN

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V V

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Diodes Incorporated

PAM2327

Recommended Operating Conditions (@T

= +25°C, unless otherwise specified.)

A

Parameter Rating Unit

Supply Voltage 2.5 to 5.5 V Operation Temperature Range -40 to +85 Junction Temperature Range -40 to +125

°C

Thermal Information

Parameter Symbol Package Max Unit

Thermal Resistance (Junction to Case)

Thermal Resistance (Junction to Ambient)

θ

JC

θ

JA

QFN2x2-12 16 QFN2x2-12 80

°C/W

Electrical Characteristics

(@TA = +25°C, VIN = 3.3V, V

Parameter Symbol Test Conditions Min Typ Max Units

Input Voltage Range UVLO Threshold Output Voltage Accuracy

Regulated Feedback Voltage PMOS Current Limit Output Voltage Line Regulation LNR Output Voltage Load Regulation LDR Quiescent Current Shutdown Current Oscillator Frequency

Drain-Source On-State Resisitance SW Leakage Current

Start-Up Time PSM Threshold EN Threshold High EN Threshold Low EN Input Current Over Temperature Protection OTP 150 °C

OTP Hysteresis OTH 30 °C

Effciency η

Output Ripple Ripple

Output Transient Ripple PG Pin Trigger Delay 90 µs

PG Pin Threshold (relative to V PG Open Drain Impedance (PG = PV

)

IN

PG Open Drain Impedance (PG = Low)

PAM2327

Document number: DS36277 Rev. 2 - 2

= 1.2V, CIN = 20µF, CO = 20µF, L = 1µH, unless otherwise specified.)

OUT

IN

Rising

V

IN

Hysteresis 400 550 mV

-4.0 +4.0 % No Load 0.591 0.60 0.609 V

FB

V

= 3.3V to 5.5V

IN

I

= 1mA to 2A

O

No Load 55 100 µA

Q

VEN = 0V

IDS = 100mA

1 µA 250 1000 µs

S

P MOSFET 40 70 mΩ

N MOSFET 30 50 mΩ

VIN = 3.3V, VO = 1.2V

1.2 V

EH

0.4 V

EL

VEN = 2V

I

= 10mA

O

V

f

R

DS(ON)

I

V

UVLO

OUT

V I

LIM

I

SD

OSC

LSW

t

I

TH

V V

I

EN

IO = 500mA to 1A IO = 1.5A IO = 2A

= 10mA

I

O

IO ≥ 300mA

= 20mA to 1A

I

O

IO = 20mA to 2A

OUT

V

PK-PK

)

±10 % 250K 500K Ω

100 Ω

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2.5 3.3 5.5 V

2.35 2.5 2.65 V

4.8 A

0.5 1 %/V 2 %

1 µA

1.0 1.2 1.6 MHz

250 mA

1.2 4 µA

75 81 85 90 85 90

%

80 89

-5 +5

-2 +2

-10 +10

-12 +12

%

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Typical Performance Characteristics (@T

A Product Line o

Diodes Incorporated

PAM2327

= +25°C, CIN = 20µF, CO = 20µF, VO = 1.2V, unless otherwise specified.)

A

PAM2327

Document number: DS36277 Rev. 2 - 2

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