Belling BL3406B-1.0V, BL3406B-1.2V, BL3406B-1.5V, BL3406B-1.8V, BL3406B-2.5V Schematic

BL3406B

V

µ H

1.5 MHz, 800mA Synchronous Buck Converter

FEATURES

• High Efficiency: Up to 96%

• 1.5MHz Constant Switching Frequency

• Current Mode Operation for Excellent

Line and Load Transient Response

• No Schottky Diode Required

• 2.5V to 5.5V Input Voltage Range

• 1.0V,1.2V,1.5V,1.8V,2.5V and 3.3V

Fixed/Adjustable Output Voltage

• 100% Duty Cycle in Dropout Mode

• Low Quiescent Current: 180µA

• Over temperature Protection

• Short Circuit Protection

• Shutdown Quiescent Current < 1µA

• Space Saving 5-Pin Thin SOT23 Package

APPLICATIONS

• Cellular and Smart Phones

• Wireless Handsets and DSL Modems

• Microprocessors and DSP Core Supplies

• PDAs

• Digital Still and Video Cameras

• GPS Receivers

DESCRIPTION

The BL3406B is a constant frequency,

1.5MHz, slope compensated current mode PWM step-down converter working under an input voltage range of 2.5V to 5.5V. This feature makes the BL3406B suitable for single cell Li-ion battery-powered applications. The internal synchronous rectifier is desired to increase efficiency without an external Schottky diode. 100% duty cycle capability extends battery life in portable devices, while the quiescent current is 180µA at no load, and drops to < 1µA in shutdown. Pulse Skipping Mode operation increases efficiency at light loads, further extending battery life. The BL3406B is offered in a low profile (1mm) 5-pin, thin SOT23 package, and is available in an adjustable version and fixed output versions of 1.0V, 1.2V, 1.5V , 1.8V, 2.5V and

3.3V.

• MP3/MP4/MP5 Players

• Portable Instruments

ORDERING INFORMATION TYPICAL APPLICATION

BL3406B –XX X XXX

Package： TRN: TSOT23-5 RN: SOT23-5

Features: P: Standard (default,

lead free)

C: Customized

Output Voltage： 10: 1.0V 12: 1.2V 15: 1.5V 18: 1.8V 25: 2.5V 33: 3.3V AD: Adjustable

V

IN

2.7V - 4.2V

C1

4.7uF

4

IN

BL3406B-ADJ

1

Run

GND

SW

V

FB

2

L1

2.2

3

C3

22pF

5

R2

200k

R1

100k

Figure 1. BL3406B-ADJ Typical Application Circuit

V

1.8V

OUT

C2

10uF

1

BL3406B

1.5 MHz, 800mA Synchronous Buck Converter

Absolute Maximum Rating

Input Supply Voltage…………………-0.3V to +6V RUN, VFB Voltages……………………-0.3V to +VIN SW Voltages……………………-0.3V to (VIN+0.3V) P-Channel Switch Source Current (DC) ………1A N-Channel Switch Sink Current (DC) …………1A

(Note 1)

Peak SW Sink and Source Current……………1.4A Operating Temperature Range……-40°C to +85°C Junction Temperature

(Note2)

………………+125°C Storage Temperature Range………-65°C to +150°C Lead Temperature (Soldering, 10s) ………+300°C

Package Information

Adjustable Output Version Fixed Output Versions

SOT23-5

TOP VIEW

V

RUN

GND

SW

1

2

3

MARKING

FB

5

4

V

IN

SOT23-5

TOP VIEW

RUN

GND

SW

1

2

3

MARKING

5

4

Part Number Top Mark Temp Range BL3406B-Adj

A J Y W

(Note3)

-40°C to +85°C

Part Number Top Mark Temp Range

BL3406B-1.0V A A Y W BL3406B-1.2V A B Y W BL3406B-1.5V A C Y W BL3406B-1.8V A D Y W

-40°C to +85°C

BL3406B-2.5V A E Y W BL3406B-3.3V A F Y W

Y 9 A B C D

Year 2009 2010 2011 2012 2013

W 1 … 26 27 28 … 53 54

Week A … Y Z a … y z

Thermal Resistance

Package JA JC TSOT23-5 SOT23-5

Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. Note 2: TJ is calculated from the ambient temperature T

T

Note 3: Y: Year of wafer manufacturing W: Week of wafer manufacturing Note 4: Thermal Resistance is specified with approximately 1 square of 1 oz copper.

= TA + (PD) x (220°C/W).

J

220°C/W 250°C/W

(Note 4)

110°C/W 130°C/W

and power dissipation P

A

according to the following formula:

D

V

OUT

V

IN

2

1.5 MHz, 800mA Synchronous Buck Converter

Pin Description

PIN NAME FUNCTION

Regulator Enable Control Input. Drive RUN above 1.5V to turn on the part.

1 RUN

2 GND Ground

3 SW

4 VIN

5 VFB/V

Drive RUN below 0.3V to turn it off. In shutdown, all functions are disabled drawing <1µA supply current. Do not leave RUN floating.

Power Switch Output. It is the switch node connection to external inductor. This pin connects to the drains of the internal P-Channel and N-Channel MOSFET switches. Supply Input Pin. Must be closely decoupled to GND, Pin 2, with a 2.2µF or greater ceramic capacitor.

VFB (BL3406B-Adj): Feedback Input Pin. Connect FB to the center point of the external resistor divider. The regulated voltage on this pin is 0.6V. V

OUT

(BL3406B-1.2/BL3406B-1.5/BL3406B-1.8): Output Voltage Feedback Pin.

OUT

An internal resistive divider divides the output voltage down for comparison to the internal reference voltage.

Block Diagram

BL3406B

3

BL3406B

1.5 MHz, 800mA Synchronous Buck Converter

Electrical Characteristics

(VIN =V

Input Voltage Range 2.5 5.5 V

Input DC Supply Current

Regulated Feedback

VFB Input Bias Current VFB = 0.65V ±30 nA

= 3.6V, TA = 25°C, unless otherwise noted.)

RUN

Parameter Conditions MIN TYP MAX Unit

Active Mode

Shutdown Mode

Voltage

VFB=0.5V or V VFB=0V, VIN=4.2V

TA= -40°C ≤ TA ≤ 85°C 0.5850 0.6000 0.6150

(Note 5)

=90%

OUT

TA = +25°C 0.5880 0.6000 0.6120

TA= 0°C ≤ TA ≤ 85°C 0.5865 0.6000 0.6135

180

0.1

300

1.0

µA µA

V V V

Reference Voltage Line

Regulation

Regulated Output Voltage

Output Overvoltage

Lockout

Output Voltage Line

Regulation

Output Voltage Load

Regulation

Peak Inductor Current

Oscillator Frequency VFB=0.6V or V

R

Note 5: 100% production test at +25°C. Specifications over the temperature range are guaranteed by design and characterization.

of P-CH MOSFET

DS(ON)

of N-CH MOSFET

DS(ON)

SW Leakage Current V

RUN Threshold -40°C ≤ TA ≤ 85°C 0.3 1.1 1.30 V

RUN Leakage Current ±0.01

BL3406B-1.2, -40°C ≤ TA ≤ 85°C 1.164 1.200 1.236 BL3406B-1.8, -40°C ≤ TA ≤ 85°C 1.746 1.800 1.854

∆V

OVL

∆V

RUN

VIN = 2.5V to 5.5V 0.04 0.4 %/V

= V

OVL

VIN=3V, VFB=0.5V or V

– VFB, Adjustable Version

OVL

= V

= 0V, VSW= 0V or 5V, VIN = 5V ±0.01

– V

OVL

VIN = 2.5V to 5.5V 0.04 0.40 %

Duty Cycle <35%

I

SW

ISW = -300mA 0.35 0.45 Ω

, Fixed Version 2.5 7.8 13 %

OUT

0.5 %

=90%

OUT

=100% 1.2 1.5 1.8 MHz

OUT

= 300mA 0.40 0.50 Ω

20 50 80 mV

1.2 A

V V

±1 µA

4

Belling BL3406B-1.0V, BL3406B-1.2V, BL3406B-1.5V, BL3406B-1.8V, BL3406B-2.5V Schematic [ru]