National Semiconductor LM27313 Technical data

July 2007

LM27313

1.6 MHz Boost Converter With 30V Internal FET Switch in
SOT-23

LM27313 1.6 MHz Boost Converter With 30V Internal FET Switch in SOT-23

General Description

The LM27313 switching regulator is a current-mode boost
converter with a fixed operating frequency of 1.6 MHz.

The use of the SOT-23 package, made possible by the mini­mal losses of the 800 mA switch, and small inductors and
capacitors result in extremely high power density. The 30V
internal switch makes these solutions perfect for boosting to
voltages of 5V to 28V.

This part has a logic-level shutdown pin that can be used to
reduce quiescent current and extend battery life.

Protection is provided through cycle-by-cycle current limiting
and thermal shutdown. Internal compensation simplifies de­sign and reduces component count.

Typical Application Circuits

Features

30V DMOS FET switch

■

1.6 MHz switching frequency

■

Low RDS(ON) DMOS FET

■

Switch current up to 800 mA

■

Wide input voltage range (2.7V–14V)

■

Low shutdown current (<1 µA)

■

5-Lead SOT-23 package

■

Uses tiny capacitors and inductors

■

Cycle-by-cycle current limiting

■

Internally compensated

■

Applications

White LED Current Source

■

PDA’s and Palm-Top Computers

■

Digital Cameras

■

Portable Phones, Games and Media Players

■

GPS Devices

■

20216824

20216857

20216801

20216858

© 2007 National Semiconductor Corporation 202168 www.national.com

Connection Diagram

LM27313

Ordering Information

Order

Number

LM27313XMF

LM27313XMFX 3K Tape and Reel SRPB

Pin Descriptions

Pin Name Function

1 SW Drain of the internal FET switch.

2 GND Analog and power ground.

3 FB Feedback point that connects to external resistive divider to set V

4 SHDN Shutdown control input. Connect to VIN if this feature is not used.

5 V

IN

See NS Package Number MF05A

Package

Type

SOT23-5 MF05A

Analog and power input.

Top View

5-Lead SOT-23 Package

Package
Drawing

20216802

Supplied

As

1K Tape and Reel SRPB

.

OUT

Package

Marking

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LM27313

Absolute Maximum Ratings (Note 1)

If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.

Storage Temperature Range −65°C to +150°C

Lead Temp. (Soldering, 5 sec.) 300°C

Power Dissipation (Note 2) Internally Limited

FB Pin Voltage −0.4V to +6V

SW Pin Voltage −0.4V to +30V

Input Supply Voltage −0.4V to +14.5V

Shutdown Input Voltage
(Survival) −0.4V to +14.5V

ESD Rating (Note 3)
Human Body Model

±2 kV

Operating Ratings

V

IN

V

SW(MAX)

V

SHDN

Junction Temperature, T
(Note 2)

θ

(SOT23-5)

J-A

J

2.7V to 14V

0V to V

-40°C to 125°C

265°C/W

Electrical Characteristics

Unless otherwise specified: VIN = 5V, V
limits in boldface type apply over the full operating temperature range (−40°C ≤ TJ ≤ +125°C). Minimum and Maximum limits are

guaranteed through test, design, or statistical correlation. Typical values represent the most likely parametric norm at TJ = 25°C,
and are provided for reference purposes only.

Symbol Parameter Conditions Min Typical Max Units

V

I

SW

R

DS(ON)

V

SHDN(TH)

I

SHDN

V

I

FB

I

ΔVFB/ΔV

f

SW

D

MAX

I

Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is
to be functional, but does not guarantee specific limits. For guaranteed specifications and conditions see the Electrical Characteristic table.

Note 2: The maximum power dissipation which can be safely dissipated for any application is a function of the maximum junction temperature, T
the junction-to-ambient thermal resistance for the SOT-23 package, θ
at any ambient temperature for designs using this device can be calculated using the formula:

Input Voltage 2.7 14 V

IN

Switch Current Limit (Note 4) 0.80 1.25 A

Switch ON Resistance

Shutdown Threshold

Shutdown Pin Bias Current

Feedback Pin Reference

FB

Voltage

Feedback Pin Bias Current

Quiescent Current

Q

FB Voltage Line Regulation

IN

Switching Frequency 1.15 1.6 1.90 MHz

Maximum Duty Cycle 80 88 %

Switch Leakage

L

= 5V, IL = 0 mA, and TJ = 25°C. Limits in standard typeface are for TJ = 25°C, and

SHDN

ISW = 100 mA

500 650

Device ON 1.5

Device OFF 0.50

V

= 0

SHDN

V

= 5V

SHDN

VIN = 3V

VFB = 1.23V

V

= 5V, Switching

SHDN

V

= 5V, Not Switching

SHDN

V

= 0

SHDN

2.7V ≤ VIN ≤ 14V

Not Switching, VSW = 5V

= 265°C/W, and the ambient temperature, TA. The maximum allowable power dissipation

J-A

0

0 2

1.205 1.230 1.255 V

60 nA

2.1 3.0 mA

400 500

0.024 1

0.02 %/V

1 µA

J(MAX)

mΩ

µA

µA

= 125°C,

30V

IN

V

If power dissipation exceeds the maximum specified above, the internal thermal protection circuitry will protect the device by reducing the output voltage as
required to maintain a safe junction temperature.

Note 3: The human body model is a 100 pF capacitor discharged through a 1.5 kΩ resistor into each pin. Test method is per JESD22-A114.
Note 4: Switch current limit is dependent on duty cycle. Limits shown are for duty cycles ≤ 50%. See Figure 3 in Application Information – MAXIMUM SWITCH

CURRENT section.

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Typical Performance Characteristics Unless otherwise specified: V

TJ = 25°C.

LM27313

Iq VIN (Active) vs Temperature

Oscillator Frequency vs Temperature

= 5V, SHDN pin is tied to VIN,

IN

Max. Duty Cycle vs Temperature

RDS(ON) vs Temperature

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20216855

20216808

Feedback Voltage vs Temperature

20216806

Current Limit vs Temperature

20216807

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20216809