Diodes PAM2303 User Manual

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Description

The PAM2303 is a 3A step-down DC-DC converter. It operates in two

different modes: PSM and PWM modes. At light load, it

automactically enters into the PSM mode to improve efficiency. At

heavy load, the constant frequency PWM control performs excellent

stability and transient response. No external compensation

components are required.

The PAM2303 supports a range of input voltages from 2.7V to 5.5V.

The output voltage is adjustable from 0.6V to the input voltage. The

PAM2303 employs internal power switch and synchronous rectifier to

minimize external part count and realize high efficiency. During

shutdown, the input is disconnected from the output and the

shutdown current is less than 1µA. Other key features include over-

temperature and short circuit protection, and under-voltage lockout to

prevent deep battery discharge.

The PAM2303 delivers 3A maximum output current while consuming

only 42µA of no-load quiescent current. Ultra-Low R

MOSFETs and 100% duty cycle operation make the PAM2303 an

ideal choice for high-output voltage, high-current applications which

require a low dropout threshold.

The PAM2303 is available in SOP-8(EP), DFN3X3-10 and QFN3X3-

16 package.

DS(ON)

integrated

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Diodes Incorporated

PAM2303

3A LOW NOISE STEP-DOWN DC-DC CONVERTER

Pin Assignments

Features

• Output Current: Up to 3A

• Output Voltage: 0.6V to V

• Input Voltage: 2.7 to 5.5V

• Efficiency up to 95%

• 42µA (typ) No Load Quiescent Current

• Shutdown Current: <1A

• 100% Duty Cycle Operation

• 1.5MHz Switching Frequency

• Analog Soft Start

• No external Compensation Required

• Current Limit Protection

• Thermal Shutdown

• SOP-8(EP), DFN3X3-10 and QFN3X3-16 Package

PAM2303

Document number: DSxxxxx Rev. 1 - 2

IN

Applications

• 5V or 3.3V Point of Load Conversion

• Telecom/Networking Equipment

• Set Top Boxes

• Storage Equipment

• Video Cards

• DDR Power Supply

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Typical Applications Circuit

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PAM2303

1R

⎛

⎞

+×=

16.0

V

O

⎜ ⎝

⎟

2R

⎠

Pin Descriptions

Name

PGND 1, 2, 3 2 — Main power ground pin.

FB 4 3 6 Feedback voltage to internal error amplifier, the threshold voltage is 0.6V.

GND 5 4 4 Signal ground for small signal components.

NC 6, 16 — 7 Not connected.

EN 7 5 5

Test 8 6 — Test mode. “Low”connection is recommended.

VIN 9 7 8, 9, 10 Bias supply. Chip main power supply pin.

PVIN 10, 11, 12 8 — Input supply for power stage. Must be closely decoupled to PGND.

SW 13, 14, 15 1 1, 2, 3 The drains of the internalmain and synchronous power MOSFET.

QFN3x3-16 SOP-8EP DFN3x3-10

Package Name

Function

Enable control input. Force this pin voltage above 1.5V, enables the chip, and below

0.3V shuts down the device.

Functional Block Diagram

PAM2303

Document number: DSxxxxx Rev. 1 - 2

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PAM2303

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 PVIN, VIN

SW Pin Voltage

FB Pin Voltage

EN Pin Voltage -0.3 to +6.0 V

Maximum Junction Temperature 150 °C

Storage Temperature Range -65 to +150 °C

Soldering Temperature 300, 5sec °C

Recommended Operating Conditions (@T

Parameter Rating Unit

Supply Voltage 2.7 to 5.5 V

Junction Temperature Range -40 to +125

Ambient Temperature Range -40 to +85

= +25°C, unless otherwise specified.)

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6 V

-0.3 to (PV

-0.3 to (V

+0.3)

IN

+0.3)

IN

= +25°C, unless otherwise specified.)

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V

°C

Thermal Information

Parameter Symbol Package Max Unit

SOP-8EP 90

Thermal Resistance (Junction to Ambient)

Thermal Resistance (Junction to Case)

PAM2303

Document number: DSxxxxx Rev. 1 - 2

θ

JA

θ

JC

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DFN3x3-10 60

QFN3x3-16 35

SOP-8EP 11

DFN3x3-10 8.5

QFN3x3-16 11

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°C/W

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PAM2303

Electrical Characteristics (@T

Parameter Symbol Test Conditions Min Typ Max Units

Input Voltage Range

Output Voltage Range

UVLO Threshold

Regulated Output Voltage Accuracy

Regulated Feedback Voltage

FB Leakage Current

Output Voltage Line Regulation LNR

Output Voltage Load Regulation LDR

Quiescent Current

Shutdown Current

Current Limit

Oscillator Frequency

Drain-Source On-State Resistance

High Efficiency η 95 %

PSM Threshold

Analog Soft Start Time

EN Threshold High

EN Threshold Low

EN Leakage Current

Over Temperature Protection OTP 150 °C

OTP Hysteresis OTH 30 °C

= +25°C, VIN = 3.6V, VO = 1.8V, CIN = 33µF, CO = 22µF, L = 2.2µH unless otherwise specified.)

A

IN

O

Rising

V

IN

Hysteresis 240 mV

V

UVLO

VIN Falling

V

IO = 0 to 3A

O

V

I

f

R

DS(ON)

V

I

FB

I

SD

LIM

OSC

I

TH

t

I

EN

0.591 0.600 0.609 V

FB

VO = 1V

V

= 2.5V to 5V

IN

I

= 0A to 3A

O

No load 42 90 µA

Q

VEN = 0V

4 A

1.2 1.5 1.8 MHz

VIN = 3.3V, VO = 1.2V, L = 1µH

From enable to output regulation 0.5 ms

S

1.5 V

EH

0.3 V

EL

VIN = VEN = 0V

High Side 85

Low Side 60

2.7 5.5 V

0.6

VIN

2.4 2.5 V

1.8 V

-3 +3 %

-50 +50 nA

0.2 %/V

0.5 %/A

1 µA

450 mA

-1.0 +1.0 µA

V

mΩ

PAM2303

Document number: DSxxxxx Rev. 1 - 2

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Typical Performance Characteristics (@T

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PAM2303

= +25°C, CIN = 10µF, CO = 10µF, L = 4.7µH unless otherwise specified.)

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PAM2303

Document number: DSxxxxx Rev. 1 - 2

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