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LM3670

SNVS250F –NOVEMBER 2004–REVISED FEBRUARY 2016

LM3670 Miniature Step-Down DC-DC Converter for Ultralow Voltage Circuits

1 Features

Input Voltage Range: 2.5 V to 5.5 V

Adjustable Output Voltages (VOUT): 0.7 V to 2.5 V

Fixed Output Voltages: 1.2 V, 1.5 V, 1.6 V, 1.8 V, 1.875 V, 3.3V

15-µA Typical Quiescent Current

350-mA Maximum Load Capability

1-MHz PWM Fixed Switching Frequency (Typical)

Automatic PFM and PWM Mode Switching

Low Dropout Operation – 100% Duty Cycle Mode

Internal Synchronous Rectification for High Efficiency

Internal Soft Start

0.1-µA Typical Shutdown Current

Current Overload Protection

Operates from a Single Li-Ion Cell or Three-Cell NiMH/NiCd Batteries

Only Three Tiny Surface-Mount External Components Required (One Inductor, Two Ceramic Capacitors)

3 Description

The LM3670 step-down DC-DC converter is optimized for powering ultralow voltage circuits from a single Li-Ion cell or three-cell NiMH/NiCd batteries. It provides up to 350-mA load current, over an input voltage range from 2.5 V to 5.5 V. There are several different fixed voltage output options available as well as an adjustable output voltage version.

The device offers superior features and performance for mobile phones and similar portable applications with complex power management systems. Automatic intelligent switching between pulse width modulation (PWM) low-noise and pulse frequency modulation (PFM) low-current mode offers improved system control. During full-power operation, a fixed-frequency 1-MHz (typical) PWM mode drives loads from approximately 70 mA to 350 mA maximum, with up to 95% efficiency. Hysteretic PFM mode extends the battery life through reduction of the quiescent current to 15 µA (typical) during light current loads and system standby. Internal synchronous rectification provides high efficiency (90% to 95% typical at loads between 1 mA and 100 mA). In shutdown mode (enable (EN) pin pulled low) the device turns off and reduces battery consumption to 0.1 µA (typical).

2 Applications

Mobile Phones and Handheld Devices

PDAs

Palm-Top PCs

Portable Instruments

Battery-Powered Devices

The LM3670 is available in a 5-pin SOT-23 package. A high switching frequency (1 MHz typical) allows use of tiny surface-mount components. Only three external surface-mount components, an inductor and two ceramic capacitors, are required.

Device Information(1)

PART NUMBER

PACKAGE

BODY SIZE (NOM)

LM3670

SOT-23 (5)

2.90 mm × 1.60 mm

(1)For all available packages, see the orderable addendum at the end of the data sheet.

Typical Application: Fixed Output

Typical Application: Adjustable Output Voltage

VIN

 

 

 

L1

 

 

 

 

 

 

 

 

 

 

 

10 µF

 

VIN

 

 

 

L1

 

 

2.5 V to 5.5 V

VIN

 

 

VOUT

 

 

 

 

 

 

5 SW

 

 

 

4.7 or 10 µH

 

 

 

1

 

2.5 V to 5.5 V

VIN

 

 

VOUT

 

CIN

 

 

 

 

COUT

 

1

5 SW

 

 

 

LM3670

 

CIN

 

 

 

4.7 µF

 

 

 

LM3670

 

 

 

GND

 

 

 

10 µF

 

 

 

 

 

2

 

 

4.7 µF

 

 

 

 

 

 

 

 

GND 2

 

 

 

 

 

 

 

 

 

 

 

 

 

COUT

 

 

 

 

 

 

 

 

 

R1

 

 

 

 

FB

 

 

 

 

 

 

10 µF

 

EN

3

4

 

 

EN

 

 

FB

 

 

 

 

 

 

3

4

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

R2

 

An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications, intellectual property matters and other important disclaimers. PRODUCTION DATA.

LM3670

SNVS250F –NOVEMBER 2004–REVISED FEBRUARY 2016 www.ti.com

Table of Contents

1

Features ..................................................................

1

 

7.4

Device Functional Modes........................................

12

2

Applications ...........................................................

1

8

Application and Implementation ........................

14

3

Description .............................................................

1

 

8.1

Application Information............................................

14

4

Revision History.....................................................

2

 

8.2

Typical Application .................................................

14

5

Connection Diagram..............................................

3

9

Power Supply Recommendations......................

18

6

Specifications.........................................................

4

10

Layout...................................................................

19

 

6.1

Absolute Maximum Ratings

4

 

10.1

Layout Guidelines .................................................

19

 

 

10.2

Layout Example

20

 

6.2

ESD Ratings

4

 

 

11 Device and Documentation Support

21

 

6.3

Recommended Operating Conditions.......................

4

 

6.4

Thermal Information ..................................................

4

 

11.1

Device Support ....................................................

21

 

6.5

Electrical Characteristics...........................................

5

 

11.2

Community Resources..........................................

21

 

6.6

Typical Characteristics ..............................................

7

 

11.3

Trademarks ...........................................................

21

7

Detailed Description ............................................

10

 

11.4

Electrostatic Discharge Caution............................

21

 

7.1

Overview

10

 

11.5

Glossary ................................................................

21

 

12 Mechanical, Packaging, and Orderable

 

 

7.2

Functional Block Diagram .......................................

10

 

 

7.3

Feature Description.................................................

11

 

Information ...........................................................

21

 

 

 

 

 

 

 

 

4 Revision History

NOTE: Page numbers for previous revisions may differ from page numbers in the current version.

Changes from Revision E (February 2013) to Revision F

Page

• Changed "(0.7V min) to "0.7 V to 2.5 V" ................................................................................................................................

1

Added Device Information and Pin Configuration and Functions sections, ESD Ratings and Thermal Information tables, Feature Description, Device Functional Modes, Application and Implementation, Power Supply Recommendations, Layout, Device and Documentation Support, and Mechanical, Packaging, and Orderable

 

Information sections................................................................................................................................................................

1

• Deleted phone and fax numbers of manufacturers from suggested inductors table ...........................................................

15

• Deleted phone and fax numbers of manufacturers from suggested capacitors table .........................................................

16

Deleted rest of text from paragraph beginning "For any output voltages...."........................................................................

17

Deleted row beginning with "1.24... "from Table 3 ..............................................................................................................

18

Changes from Revision D (February 2013) to Revision E

Page

• Changed layout of National Data Sheet to TI format ...........................................................................................................

19

2

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SNVS250F –NOVEMBER 2004 –REVISED FEBRUARY 2016

5 Connection Diagram

DBV Package

5-Pin SOT-23

Top View

SW

FB

54

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

VIN

 

GND

 

EN

 

 

1

2

3

 

 

 

 

Pin Functions

 

PIN

TYPE

DESCRIPTION

NUMBE

NAME

R

 

 

 

 

 

1

VIN

Power

Power supply input. Connect to the input filter capacitor

( Typical Application: Fixed Output).

2

GND

Ground

Ground pin.

3

EN

Digital

Enable input.

4

FB

Analog

Feedback analog input. Connect to the output filter capacitor

 

 

(Typical Application: Fixed Output).

 

 

 

 

 

 

Switching node connection to the internal PFET switch and NFET synchronous rectifier.

5

SW

Analog

Connect to an inductor with a saturation current rating that exceeds the 750-mA maximum

 

 

 

switch peak current limit specification.

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6 Specifications

6.1 Absolute Maximum Ratings

over operating free-air temperature range (unless otherwise noted)(1)(2)

 

 

MIN

MAX

UNIT

VIN pin: voltage to GND

 

–0.2

6

V

EN pin: voltage to GND

 

–0.2

6

V

FB, SW pins

 

(GND −0.2)

VIN + 0.2

V

Junction temperature, TJ-MAX

 

–45

125

°C

Maximum lead temperature

(soldering, 10 seconds)

 

260

°C

Storage temperature, Tstg

 

–45

150

°C

(1)Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, which do not imply functional operation of the device at these or any other conditions beyond those indicated under Recommended Operating Conditions. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.

(2)If Military/Aerospace specified devices are required, contact the TI Sales Office/Distributors for availability and specifications.

6.2

ESD Ratings

 

 

 

 

 

 

VALUE

UNIT

 

 

Human-body model (HBM), per ANSI/ESDA/JEDEC JS-001(1)

±2000

 

V(ESD)

Electrostatic discharge

Charged-device model (CDM), per JEDEC specification JESD22-

±200

V

 

 

C101(2)

 

(1)JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process.

(2)JEDEC document JEP157 states that 250-V CDM allows safe manufacturing with a standard ESD control process.

6.3 Recommended Operating Conditions

over operating free-air temperature range (unless otherwise noted)(1)

 

MIN

NOM

MAX

UNIT

Input voltage

2.5

 

5.5

A

Recommended load current

0

 

350

mA

Junction temperature, TJ

–40

 

125

°C

Ambient temperature, TA

–40

 

85

°C

(1) All voltages are with respect to the potential at the GND pin.

 

 

 

 

6.4 Thermal Information

 

 

LM3670

 

 

THERMAL METRIC(1)

DBV (SOT-23)

UNIT

 

 

5 PINS

 

RθJA

Junction-to-ambient thermal resistance

163.3

°C/W

RθJC(top)

Junction-to-case (top) thermal resistance

114.3

°C/W

RθJB

Junction-to-board thermal resistance

26.8

°C/W

ψJT

Junction-to-top characterization parameter

12.4

°C/W

ψJB

Junction-to-board characterization parameter

26.3

°C/W

(1)For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application report, SPRA953.

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6.5 Electrical Characteristics

Unless otherwise specified, limits for typical values are TJ = 25°C, and minimum and maximum limits apply over the full operating junction temperature range (−40°C ≤ TJ ≤ +125°C); VIN = 3.6 V, VOUT = 1.8 V, IOUT = 150 mA, EN = VIN.

 

PARAMETER

TEST CONDITIONS

MIN

TYP

MAX

UNIT

V

Input voltage

See(1)

2.5

 

5.5

V

IN

 

 

 

 

 

 

 

 

2.5 V ≤ VIN ≤ 5.5 V

–2%

 

4%

 

 

Fixed output voltage: 1.2 V

IOUT = 10 mA

 

 

 

 

 

2.5 V ≤ VIN ≤ 5.5 V

–4.5%

 

4%

 

 

 

 

 

 

 

0 mA ≤ IOUT ≤ 150 mA

 

 

 

 

 

 

2.5 V ≤ VIN ≤ 5.5 V

–2.5%

 

4%

 

 

Fixed output voltage: 1.5 V

IOUT = 10 mA

 

 

 

 

 

2.5 V ≤ VIN ≤ 5.5 V

–5%

 

4%

 

 

 

 

 

 

 

0 mA ≤ IOUT ≤ 350 mA

 

 

 

 

 

 

2.5 V ≤ VIN ≤ 5.5 V

–2.5%

 

4%

 

 

Fixed output voltage: 1.6 V, 1.875 V

IOUT = 10 mA

 

 

 

 

 

2.5 V ≤ VIN ≤ 5.5V

–5.5%

 

4%

 

 

 

 

 

VOUT

 

0 mA ≤ IOUT ≤ 350 mA

 

 

 

 

 

2.5 V ≤ VIN ≤ 5.5 V

–1.5%

 

3%

 

 

Fixed output voltage: 1.8 V

IOUT = 10 mA

 

 

 

 

 

2.5 V ≤ VIN ≤ 5.5 V

–4.5%

 

3%

 

 

 

 

 

 

 

0 mA ≤ IOUT ≤ 350 mA

 

 

 

 

 

 

3.6 V ≤ VIN ≤ 5.5 V

–2%

 

4%

 

 

Fixed output voltage: 3.3 V

IOUT = 10 mA

 

 

 

 

 

3.6V ≤ VIN ≤ 5.5V

–6%

 

4%

 

 

 

 

 

 

 

0 mA ≤ IOUT ≤ 350 mA

 

 

 

 

 

 

2.5 V ≤ VIN ≤ 5.5 V

–2.5%

 

4.5%

 

 

Adjustable output voltage(2)

IOUT = 10 mA

 

 

 

 

 

 

 

 

 

2.5 V ≤ VIN ≤ 5.5 V

–4%

 

4.5%

 

 

 

 

 

 

 

0 mA ≤ IOUT ≤ 150 mA

 

 

 

 

Line_reg

Line regulation

2.5 V ≤ VIN ≤ 5.5 V

 

0.26

 

%/V

 

 

IOUT = 10 mA

 

 

 

 

Load_reg

Load regulation

150 mA ≤ IOUT ≤ 350 mA

 

0.0014

 

%/mA

VREF

Internal reference voltage

 

 

0.5

 

V

IQ_SHDN

Shutdown supply current

TA = 85ºC

 

0.1

1

µA

 

 

No load, device is not switching

 

 

 

 

IQ

DC bias current into VIN

(VOUT forced higher than

 

15

30

µA

 

 

programmed output voltage)

 

 

 

 

VUVLO

Minimum VIN below which VOUT is

TA = −40°C ≤ TJ ≤ 125°C

 

2.4

 

V

disabled

 

 

RDSON (P)

Pin-pin resistance for PFET

VIN = VGS= 3.6V

 

360

690

mΩ

RDSON (N)

Pin-pin resistance for NFET

VIN = VGS= 3.6 V

 

250

660

mΩ

ILKG (P)

P channel leakage current

VDS = 5.5 V, TA = 25°C

 

0.1

1

µA

ILKG (N)

N channel leakage current

VDS = 5.5 V, TA = 25°C

 

0.1

1.5

µA

ILIM

Switch peak current limit

 

400

620

750

mA

(1)The input voltage range recommended for the specified output voltages are given below: VIN = 2.5 V to 5.5 V for 0. 7 V ≤ VOUT < 1.875 V, VIN = ( VOUT + VDROPOUT) to 5.5 for 1.875 ≤ VOUT ≤ 3.3 V, where VDROPOUT = ILOAD × (RDSON (P) + RINDUCTOR).

(2)Output voltage specification for the adjustable version includes tolerance of the external resistor divider.

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Electrical Characteristics (continued)

Unless otherwise specified, limits for typical values are TJ = 25°C, and minimum and maximum limits apply over the full operating junction temperature range (−40°C ≤ TJ ≤ +125°C); VIN = 3.6 V, VOUT = 1.8 V, IOUT = 150 mA, EN = VIN.

 

PARAMETER

TEST CONDITIONS

MIN

TYP

MAX

UNIT

 

 

VIN = 3.6 V, VOUT = 1.8 V

 

91%

 

 

 

 

ILOAD = 1 mA

 

 

 

 

 

 

VIN = 3.6 V, VOUT = 1.8 V

 

94%

 

 

 

 

ILOAD = 10 mA

 

 

 

 

 

 

VIN = 3.6 V, VOUT = 1.8 V

 

94%

 

 

η

Efficiency

ILOAD = 100 mA

 

 

 

 

VIN = 3.6 V, VOUT = 1.8 V

 

94%

 

 

 

 

 

 

 

 

 

ILOAD = 200 mA

 

 

 

 

 

 

VIN = 3.6 V, VOUT = 1.8 V

 

92%

 

 

 

 

ILOAD = 300 mA

 

 

 

 

 

 

VIN = 3.6 V, VOUT = 1.8 V

 

90%

 

 

 

 

ILOAD = 350 mA

 

 

 

 

VIH

Logic high input

 

1.3

 

 

V

VIL

Logic low input

 

 

 

0.4

V

IEN

Enable (EN) input current

 

 

0.01

1

µA

ƒOSC

Internal oscillator frequency

PWM mode

550

1000

1300

kHz

6

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6.6 Typical Characteristics

Unless otherwise stated, VIN = 3.6 V and VOUT= 1.8 V.

 

20

 

 

 

 

 

 

 

0.1

 

 

 

 

 

 

A)(P

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

QUIESCENT

 

 

TA = 85°C

 

 

 

A)(P

 

 

 

 

 

 

 

15

 

 

TA = 25°C

 

 

0.05

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

I

 

 

 

TA = -40°C

 

 

SHUTDOWN

 

 

 

 

 

 

 

LOAD

 

 

 

 

 

 

 

I

 

 

 

 

 

 

 

NO

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

10

 

 

 

 

 

 

 

0

 

 

 

 

 

 

 

2.5

3

3.5

4

4.5

5

5.5

 

-40

-20

0

20

40

60

80

 

 

 

 

VIN (V)

 

 

 

 

 

 

TEMPERATURE (°C)

 

 

Figure 1. IQ (Non-Switching) vs VIN

Figure 2. IQ vs Temperature

 

1.83

 

 

 

 

 

 

 

1.9

 

 

 

 

 

 

 

 

1.82

IOUT = 10 mA

 

VIN = 3.6V

 

 

1.88

 

 

 

 

 

 

 

 

PFM mode

 

 

 

 

 

1.86

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1.81

 

 

 

 

 

 

 

1.84

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

PFM Mode

 

 

 

 

 

(V)

 

 

 

 

 

 

 

(V)

1.82

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

IOUT = 150 mA

 

 

 

 

 

 

 

 

 

 

 

 

OUT

1.80

 

 

 

 

OUT

1.8

 

 

 

PWM Mode

 

PWM mode

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

V

 

 

 

 

 

 

 

V

1.78

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1.79

 

 

 

VIN = 5.5V

 

 

1.76

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1.78

 

VIN = 2.5V

 

 

 

 

1.74

 

 

 

 

 

 

 

 

 

VIN = 3.6V

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1.72

 

 

 

 

 

 

 

 

1.77

 

 

 

 

 

 

 

1.7

 

 

 

 

 

 

 

 

-40

-20

0

20

40

60

80

 

0

50

100

150

200

250

300

350

 

 

 

TEMPERATURE (°C)

 

 

 

 

 

 

ILOAD (mA)

 

 

 

Figure 3. VOUT vs VIN

Figure 4. VOUT vs IOUT

 

100

 

 

 

 

 

 

100

 

 

 

 

 

 

 

 

95

VIN = 2.7V

 

 

 

 

 

 

 

 

 

 

 

 

 

90

 

 

 

 

95

 

 

 

ILOAD = 150 mA

 

 

 

 

 

 

 

 

 

 

 

 

(%)

85

 

 

 

 

 

(%)

 

 

 

 

 

 

 

 

80

 

 

 

 

 

90

 

 

 

 

 

 

 

EFFICIENCY

 

 

 

 

 

EFFICIENCY

 

 

 

 

 

 

 

60

 

 

 

 

 

80

 

 

 

 

 

 

 

 

75

 

VIN = 5.0V

 

 

 

 

 

 

 

ILOAD = 1 mA

 

 

 

70

 

 

 

 

 

 

85

 

 

 

 

 

 

 

 

65

 

 

 

 

 

 

 

 

ILOAD = 300 mA

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

55

 

 

VIN = 3.7V

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

50

 

 

 

 

 

 

75

 

 

 

 

 

 

 

 

45

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

40

10 -1

100

101

102

103

 

70

 

 

 

 

 

 

 

 

10 -2

 

2.5

3

3.5

4

4.5

5

5.5

6

 

 

 

ILOAD (mA)

 

 

 

 

 

 

VIN (V)

 

 

 

Figure 5. Efficiency vs IOUT

Figure 6. Efficiency vs VIN

 

 

 

 

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Typical Characteristics (continued)

Unless otherwise stated, VIN = 3.6 V and VOUT= 1.8 V.

 

1010

ILOAD = 150 mA

 

 

1000

 

 

990

 

VIN = 3.6V

 

980

VIN = 5.5V

(kHz)

970

 

 

950

 

 

 

960

 

 

FREQUENCY

940

 

VIN = 2.5V

 

 

930

 

 

 

 

 

 

920

 

 

 

910

 

 

 

900

 

 

 

890

 

 

 

880

 

 

 

870

 

 

 

860

 

 

 

850

 

 

 

840

 

 

-40-30 -20 -10 0 10 20 30 40 50 60 70 80 TEMPERATURE (°C)

Figure 7. Frequency vs Temperature

 

IOUT = 100 MA

 

VIN = 3.6V

 

VIN RISE TIME = 10 mS

 

VIN = 2.6V

TRANSIENT

VOUT = 1.8V

LINE

(20 MV/DIV)

 

 

TIME (200 mS/DIV)

VIN = 2.6 V to 3.6 V

ILOAD = 100 mA

 

 

Figure 9. Line Transient

mA)280 -

VOUT (50 mV/Div)

mA(3 STEP

 

 

LOAD

ILOAD = 280 mA

CURRENT

 

ILOAD = 3 mA

TIME (100 Ps/DIV)

ILOAD = 3 mA to 280 mA

Figure 11. Load Transient

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0.8

 

 

 

 

P FET

 

 

 

 

N FET

 

 

 

 

 

 

 

 

 

 

 

0.7

 

 

 

 

 

 

):

 

 

 

TA = 85°C

 

 

(

0.6

 

 

 

 

CHANNELP

 

 

 

 

 

 

TA = 25°C

 

 

 

 

 

 

 

0.5

 

 

TA = -40°C

 

 

 

 

 

 

 

 

0.4

 

 

 

 

 

 

N,-

 

 

 

 

 

 

 

 

 

 

 

 

 

DSon

0.3

 

 

 

 

 

 

 

 

 

 

 

 

 

R

0.2

 

 

 

 

 

 

 

 

 

 

 

 

 

 

0.1

 

 

 

 

 

 

 

2.5

3

3.5

4

4.5

5

5.5

VIN (V)

Figure 8. RDSON vs. VIN P and N Channels

 

VIN = 4.6V

 

VIN = 3.6V

TRANSIENT

VOUT = 1.8V

LINE

(20 MV/DIV)

 

 

TIME (100 mS/DIV)

VIN = 3.6 V to 4.6 V

ILOAD = 100 mA

 

Figure 10. Line Transient

mA)70 -mA (0

VOUT (50 mV/Div)

 

STEPLOAD

Inductor Current = 200 mA/Div

CURRENT

ILOAD = 70 mA

 

ILOAD = 0 mA

TIME (100 Ps/DIV)

ILOAD = 0 mA to 70 mA

Figure 12. Load Transient

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SNVS250F –NOVEMBER 2004 –REVISED FEBRUARY 2016

Typical Characteristics (continued)

Unless otherwise stated, VIN = 3.6 V and VOUT= 1.8 V.

 

VSWITCH

 

 

ILOAD = 150 mA

 

 

 

VSWITCH

 

(5V/Div)

 

 

(5V/Div)

 

VOUT

 

 

 

MODE

(20 mV/Div)

 

MODE

 

 

 

VOUT

 

 

(20 mV/Div)

 

 

 

PFM

Inductor Current

 

PWM

Inductor Current

(100 mA/Div)

 

 

(200 mA/Div)

 

 

 

TIME (2 Ps/DIV)

 

 

TIME (1 Ps/DIV)

Figure 13. PFM Mode VSW, VOUT, IINDUCTOR vs Time

Figure 14. PWM Mode VSW, VOUT, IINDUCTOR vs Time

 

mA)

VIN (2V/Div)

 

 

 

280-mA (3

 

 

 

VOUT (1V/Div)

 

 

 

STEP

 

 

 

 

LOAD

Inductor

 

 

 

(200CurrentmA/

 

 

 

Div)

 

 

 

CURRENT

 

 

 

 

 

TIME (100 Ps/DIV)

 

 

 

ILOAD = 350 mA

 

 

 

 

Figure 15. Soft Start VIN, VOUT, IINDUCTOR vs Time

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