Diodes PAM2301 User Manual

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Description

The PAM2301 is a step-down current-mode, DC-DC converter. At

heavy load, the constant frequency PWM control performs excellent

stability and transient response. To ensure the longest battery life in

portable applications, the PAM2301 provides a power-saving Pulse-

Skipping Modulation (PSM) mode to reduce quiescent current under

light load operation to save power.

The PAM2301 supports a range of input voltages from 2.5V to 5.5V,

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

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

adjustable from 0.6V to the input voltage, while the part number suffix

PAM2301-XX indicates pre-set output voltage of 3.3V, 2.8V, 2.5V,

1.8V, 1.5V, 1.2V or adjustable. All versions employ 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 0.1mA. Other

key features include under-voltage lockout to prevent deep battery

discharge.

The PAM2301 is available in TSOT25 package.

Features

• Efficiency up to 96%

• Only 40μA (typ) Quiescent Current

• Output Current: Up to 800mA

• Internal Synchronous Rectifier

• 1.5MHz Switching Frequency

• Soft Start

• Under-Voltage Lockout

• Short Circuit Protection

• Thermal Shutdown

• 5-Pin Small TSOT25 Package

• Pb-Free Package

Diodes Incorporated

800mA STEP-DOWN DC-DC CONVERTER

Pin Assignments

Applications

• Cellular Phone

• Portable Electronics

• Wireless Devices

• Cordless Phone

• Computer Peripherals

• Battery-Powered Widgets

• Electronic Scales

• Digital Frame

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PAM2301

TSOT25

Typical Applications Circuit

Fixed Output Voltage Adjustable Output Voltage

PAM2301

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Pin Descriptions

Pin Number Pin Name Function

1 EN

2 GND Ground

3 SW The drains of the internal main and synchronous power MOSFET.

4 VIN Power Supply

5 VOUT/FB

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

VOUT: Output voltage feedback pin, an internal resistive divider divides the
output voltage down for comparison to the internal reference voltage.
FB: Feedback voltage to internal error amplifier, the threshold voltage is 0.6V.

Functional Block Diagram

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PAM2301

PAM2301

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PAM2301

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.

= +25°C, unless otherwise specified.)

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Parameter Rating Unit

Input Voltage -0.3 to +6.0 V

EN, FB Pin Voltage

SW Pin Voltage

-0.3 to V

-0.3 to (V

IN

+ 0.3)

IN

V

V

Junction Temperature +150 °C

Storage Temperature Range -65 to +150 °C

Soldering Temperature +300, 5sec °C

Recommended Operating Conditions (@T

= +25°C, unless otherwise specified.)

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Parameter Rating Unit

Supply Voltage 2.5 to 5.5 V

Operation Temperature Range -40 to +85

Juntion Temperature Range -40 to +125

°C

Thermal Information

Parameter Symbol Max Unit

Thermal Resistance (Junction to Case)

Thermal Resistance (Junction to Ambient)

Internal Power Dissipation

θ

JC

θ

JC

P

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Electrical Characteristics (@T

= +25°C, VIN = 3.6V, VO = 1.8V, CIN = 10µF, L = 4.7µH unless otherwise specified.)

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Parameter Symbol Test Conditions Min Typ Max Units

Input Voltage Range

Regulated Feedback Voltage

Reference Voltage Line Regulation

Regulated Output Voltage Accuracy

Peak Inductor Current

V

IN

V

FB

ΔV

FB

V

IO = 100mA

O

I

V

PK

Output Voltage Line Regulation LNR

Output Voltage Load Regulation LDR

Quiescent Current

Shutdown Current

Oscillator Frequency

Drain-Source On-State Resistance

SW Leakage Current

I

Q

I

VEN = 0V

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OSC

R

I

DS(ON)

I

LSW

IN

V

= 2.5V to 5V, IO = 10mA

IN

I

= 1mA to 800mA

O

No load 40 70 µA

= 100%

V

O

VFB = 0V or VO = 0V

= 100mA

DS

High Efficiency η 96 %

EN Threshold High

EN Threshold Low

EN Leakage Current

V

EH

V

EL

I

EN

Over Temperature Protection OTP 150 °C

OTP Hysteresis OTH 30 °C

PAM2301

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130

250

°C/W

400 mW

= 3V,VFB = 0.5V or VO = 90%

P MOSFET 0.30 0.45 Ω
N MOSFET 0.35 0.50 Ω

2.5 5.5 V

0.588 0.600 0.612 V

0.3 %/V

-3 +3 %

1.2 A

0.2 0.5 %/V

0.5 1.5 %

0.1 1.0 µA

1.2 1.5 1.8 MHz

500 kHz

±0.01 1 µA

1.5 V

0.3 V

±0.01 µA

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Typical Performance Characteristics (@T

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PAM2301

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

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PAM2301

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