Diodes PAM2307 User Manual

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Description

The PAM2307 is a 3A step-down DC-DC converter. At heavy load,

the constant-frequency PWM control performs excellent stability and

transient response. No external compensation components are

required.

The PAM2307 supports a range of input voltages from 2.7V to 5.5V,

allowing the use of a single Li+/Li-polymer cell, multiple Alkaline/

NiMH cell,and other standard power sources. The output voltage is

adjustable from 0.6V to the input voltage. The PAM2307 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 PAM2307 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 PAM2307 an

ideal choice for high output voltage, high current applications which

require a low dropout threshold.

The PAM2307 is available in QFN3x3 16-Pin and SOP-8(EP)

package.

DS(ON)

integrated

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: <1µA

• 100% Duty Cycle Operation

• 1.5MHz Switching Frequency

• Internal Soft Start

• No external Compensation Required

• Current Limit Protection

• Thermal Shutdown

• QFN3x3 16-Pin and SOP-8(EP) Package

IN

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3A LOW NOISE STEP-DOWN DC-DC CONVERTER

Pin Assignments

Applications

• 5V or 3.3V Point of Load Conversion

• Telecom/Networking Equipment

• Set Top Boxes

• Storage Equipment

• Video Cards

• DDR Power Supply

PAM2307

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Typical Applications Circuit

Pin Descriptions

Name

QFN3x3-16L SOP-8(EP)

Package Name

PGND 1, 2, 3 2

FB 4 3

GND 5 4

NC 6, 16 —

EN 7 5

TEST 8 6

VIN 9 7

PVIN 10, 11, 12 8

SW 13, 14, 15 1

Functional Block Diagram

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PAM2307

⎞

⎛

1R

⎟

V

Main power ground pin.

Feedback voltage to internal error amplifier, the threshold voltage is 0.6V.

Signal ground for small signal components.

No connection.

Enable control input. Force this pin voltage above 1.5V, enables the chip, and below 0.3V shuts down the device.

Test Mode(no connect or to Ground).

Bias supply. Chip main power supply pin.

Input supply for power stage. Must be closely decoupled to PGND.

The drains of the internal main and synchronous power MOSFET.

⎜

16.0O

⎜ ⎝

+×=

⎟

2R

⎠

Function

PAM2307

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PAM2307

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

= +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

Recommended Operating Conditions (@T

Parameter Rating Unit

Supply Voltage 2.5 to 5.5 V

Junction Temperature Range -40 to +125

Ambient Temperature Range -40 to +85

V

= +25°C, unless otherwise specified.)

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°C

Thermal Information

Parameter Symbol Package Max Unit

Thermal Resistance (Junction to Ambient)

Thermal Resistance (Junction to Case)

θ

JA

θ

JC

PAM2307

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QFN3x3-16 35

SOP-8(EP) 90

QFN3x3-16 14

SOP-8(EP) 11

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°C/W

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PAM2307

Electrical Characteristics (@T

Parameter Symbol Test Conditions Min Typ Max Units

Input Voltage Range

Output Voltage Range

UVLO Threshold

Regulated Output Votlage 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 Resisitance

High Efficiency η 95 %

Start-Up Time

EN Threshold High

EN Threshold Low

EN Leakage Current

Over Temperature Protection OTP 150 °C

OTP Hysteresis OTH 30 °C

PAM2307

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= +25°C, VIN = 3.6V, VO = 1.8V, CIN = 22µF, C

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IN

O

Rising

V

IN

Hysteresis 240 mV

V

UVLO

VIN Falling

V

IO = 0 to 3A, VIN = 2.5 to 5.5V

O

V

I

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R

DS(ON)

V

I

FB

I

SD

LIM

OSC

t

I

EN

0.588 0.600 0.612 V

FB

VO =1V

V

= 2.5V to 5V

IN

I

= 0A to 3A

O

No Load 42 90 µA

Q

VEN = 0V

From enable to output regulation 3 ms

S

1.5 V

EH

0.3 V

EL

High Side 0.140 Ω

Low Side 0.09 Ω

VIN = VEN = 0V

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= 22µF, L = 2.2µH, unless otherwise specified.)

O

2.5 5.5 V

0.6

VIN

V

2.4 2.5 V

1.8 V

-2 +2 %

0.2 µA

0.2 %/V

0.5 %/A

1 µA

3.5 A

1.2 1.5 1.8 MHz

-1.0 +1.0 µA

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Typical Performance Characteristics (@T

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= +25°C, CIN = 22*2µF, CO = 22µF, unless otherwise specified.)

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PAM2307

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