LINEAR TECHNOLOGY LTC3406, LTC3406-1.5, LTC3406-1.8 Technical data

OUTPUT CURRENT (mA)

70

EFFICIENCY (%)

80

90

95

0.1 10 100 1000

3406 F01b

60

1

85

75

65

VIN = 2.7V

V

OUT

= 1.8V

VIN = 4.2V

VIN = 3.6V

查询LTC3406-1.5供应商

FEATURES

■

High Efficiency: Up to 96%

■

Very Low Quiescent Current: Only 20µA
During Operation

■

600mA Output Current

■

2.5V to 5.5V Input Voltage Range

■

1.5MHz Constant Frequency Operation

■

No Schottky Diode Required

■

Low Dropout Operation: 100% Duty Cycle

■

0.6V Reference Allows Low Output Voltages

■

Shutdown Mode Draws ≤1µA Supply Current

■

Current Mode Operation for Excellent Line and
Load Transient Response

■

Overtemperature Protected

■

Low Profile (1mm) ThinSOTTM Package

U

APPLICATIO S

■

Cellular Telephones

■

Personal Information Appliances

■

Wireless and DSL Modems

■

Digital Still Cameras

■

MP3 Players

■

Portable Instruments

LTC34 0 6

LTC34 06 -1.5/LTC 3 4 0 6-1. 8

1.5MHz, 600mA

Synchronous Step-Down

Regulator in ThinSOT

U

DESCRIPTIO

®

The LTC
nous buck regulator using a constant frequency, current
mode architecture. The device is available in an adjustable
version and fixed output voltages of 1.5V and 1.8V. Supply
current during operation is only 20µA and drops to ≤1µA
in shutdown. The 2.5V to 5.5V input voltage range makes
the LTC3406 ideally suited for single Li-Ion battery-pow­ered applications. 100% duty cycle provides low dropout
operation, extending battery life in portable systems.
Automatic Burst Mode
light loads, further extending battery life.

Switching frequency is internally set at 1.5MHz, allowing
the use of small surface mount inductors and capacitors.

The internal synchronous switch increases efficiency and
eliminates the need for an external Schottky diode. Low
output voltages are easily supported with the 0.6V feed­back reference voltage. The LTC3406 is available in a low
profile (1mm) ThinSOT package.

, LTC and LT are registered trademarks of Linear Technology Corporation.

Burst Mode is a registered trademark of Linear Technology Corporation.
ThinSOT is a trademark of Linear Technology Corporation.
Protected by U.S. Patents, including 6580258, 5481178.

3406 is a high efficiency monolithic synchro-

®

operation increases efficiency at

TYPICAL APPLICATIO

V

IN

2.7V

TO 5.5V

Figure 1a. High Efficiency Step-Down Converter

4

CIN**

4.7µF
CER

1

*

MURATA LQH32CN2R2M33

**

TAIYO YUDEN JMK212BJ475MG

†

TAIYO YUDEN JMK316BJ106ML

V

IN

LTC3406-1.8

V

RUN

GND

2

SW

OUT

3

5

2.2µH*

U

3406 F01a

C

OUT

10µF
CER

†

V

OUT

1.8V
600mA

Figure 1b. Efficiency vs Load Current

3406fa

1

LTC34 0 6
LTC34 06 -1.5/LTC 3 4 06 -1.8

WWWU

ABSOLUTE AXI U RATI GS

(Note 1)

Input Supply Voltage .................................. – 0.3V to 6V

RUN, VFB Voltages ..................................... – 0.3V to V

SW Voltage .................................. – 0.3V to (VIN + 0.3V)

P-Channel Switch Source Current (DC) ............. 800mA

N-Channel Switch Sink Current (DC) ................. 800mA

UU

W

Peak SW Sink and Source Current ........................ 1.3A

Operating Temperature Range (Note 2) .. –40°C to 85°C

IN

Junction Temperature (Note 3)............................ 125°C

Storage Temperature Range ................ –65°C to 150°C

Lead Temperature (Soldering, 10 sec)................. 300°C

PACKAGE/ORDER I FOR ATIO

ORDER PART

TOP VIEW

RUN 1

GND 2

SW 3

S5 PACKAGE

5-LEAD PLASTIC TSOT-23

T

= 125°C, θJA = 250°C/ W, θJC = 90°C/ W

JMAX

Consult LTC Marketing for parts specified with wider operating temperature ranges.

5 V

4 V

FB

IN

NUMBER

LTC3406ES5

S5 PART MARKING

LTA5

TOP VIEW

RUN 1

GND 2

SW 3

S5 PACKAGE

5-LEAD PLASTIC TSOT-23

T

= 125°C, θJA = 250°C/ W, θJC = 90°C/ W

JMAX

5 V

4 V

OUT

IN

ORDER PART

NUMBER

LTC3406ES5-1.5
LTC3406ES5-1.8

S5 PART MARKING

LTD6
LTC4

ELECTRICAL CHARACTERISTICS

The ● denotes specifications which apply over the full operating temperature range, otherwise specifications are TA = 25°C.
VIN = 3.6V unless otherwise specified.

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

I

VFB

V

FB

∆V

FB

V

OUT

∆V

OUT

I

PK

V

LOADREG

V

IN

I

S

f

OSC

R

PFET

R

NFET

I

LSW

Feedback Current ● ±30 nA

Regulated Feedback Voltage LTC3406 (Note 4) TA = 25°C 0.5880 0.6 0.6120 V

LTC3406 (Note 4) 0°C T
LTC3406 (Note 4) –40°C ≤ T

Reference Voltage Line Regulation VIN = 2.5V to 5.5V (Note 4) ● 0.04 0.4 %/V

Regulated Output Voltage LTC3406-1.5, I

LTC3406-1.8, I

Output Voltage Line Regulation VIN = 2.5V to 5.5V ● 0.04 0.4 %/V

Peak Inductor Current VIN = 3V, VFB = 0.5V or V

Duty Cycle < 35%

Output Voltage Load Regulation 0.5 %

Input Voltage Range ● 2.5 5.5 V

Input DC Bias Current (Note 5)
Active Mode V
Sleep Mode V
Shutdown V

Oscillator Frequency VFB = 0.6V or V

R

of P-Channel FET ISW = 100mA 0.4 0.5 Ω

DS(ON)

R

of N-Channel FET ISW = –100mA 0.35 0.45 Ω

DS(ON)

SW Leakage V

= 0.5V or V

FB

= 0.62V or V

FB

= 0V, VIN = 4.2V 0.1 1 µA

RUN

= 0V or V

V

FB

= 0V, VSW = 0V or 5V, VIN = 5V ±0.01 ±1 µA

RUN

OUT
OUT

OUT

OUT

OUT

≤ 85°C 0.5865 0.6 0.6135 V

A

≤ 85°C ● 0.5850 0.6 0.6150 V

A

= 100mA ● 1.455 1.500 1.545 V
= 100mA ● 1.746 1.800 1.854 V

= 90%, 0.75 1 1.25 A

OUT

= 90%, I

= 103%, I

OUT

= 100% ● 1.2 1.5 1.8 MHz

= 0V 210 kHz

= 0A 300 400 µA

LOAD

= 0A 20 35 µA

LOAD

3406fa

2

LTC34 0 6

LTC34 06 -1.5/LTC 3 4 0 6-1. 8

ELECTRICAL CHARACTERISTICS

The ● denotes specifications which apply over the full operating temperature range, otherwise specifications are TA = 25°C.

= 3.6V unless otherwise specified.

V

IN

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

V

I

RUN

RUN

RUN Threshold ● 0.3 1 1.5 V

RUN Leakage Current ● ±0.01 ±1 µA

Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.

Note 2: The LTC3406E is guaranteed to meet performance specifications
from 0°C to 70°C. Specifications over the –40°C to 85°C operating
temperature range are assured by design, characterization and correlation
with statistical process controls.

Note 3: T
dissipation P

Note 4: The LTC3406 is tested in a proprietary test mode that connects
V

Note 5: Dynamic supply current is higher due to the gate charge being

is calculated from the ambient temperature TA and power

J

LTC3406: T

to the output of the error amplifier.

FB

delivered at the switching frequency.

UW

TYPICAL PERFOR A CE CHARACTERISTICS

(From Figure1a Except for the Resistive Divider Resistor Values)

Efficiency vs Input Voltage

100

I

95

90

85

80

75

70

EFFICIENCY (%)

65

60

55

50

= 100mA

OUT

I

= 1mA

OUT

I

= 600mA

OUT

I

= 0.1mA

OUT

V

= 1.8V

OUT

2

3

4

INPUT VOLTAGE (V)

I

OUT

= 10mA

5

6

3406 G01

Efficiency vs Output Current

95

V

= 1.2V

OUT

90

85

80

75

EFFICIENCY (%)

70

65

60

0.1 10 100 1000

VIN = 2.7V

VIN = 4.2V

VIN = 3.6V

1

OUTPUT CURRENT (mA)

according to the following formula:

D

= TA + (PD)(250°C/W)

J

Efficiency vs Output Current

95

V

= 1.5V

OUT

90

VIN = 2.7V

3406 G02

85

80

75

EFFICIENCY (%)

70

65

60

0.1 10 100 1000

VIN = 4.2V

VIN = 3.6V

1
OUTPUT CURRENT (mA)

3406 G03

Efficiency vs Output Current

100

V

= 2.5V

OUT

95

VIN = 2.7V

90

85

80

75

EFFICIENCY (%)

70

65

60

0.1 10 100 1000

VIN = 3.6V

VIN = 4.2V

1
OUTPUT CURRENT (mA)

3406 G04

Reference Voltage vs
Temperature

0.614
VIN = 3.6V

0.609

0.604

0.599

0.594

REFERENCE VOLTAGE (V)

0.589

0.584

–50

–25 0

TEMPERATURE (°C)

50 100 125

25 75

3406 G05

Oscillator Frequency vs
Temperature

1.70
VIN = 3.6V

1.65

1.60

1.55

1.50

1.45

FREQUENCY (MHz)

1.40

1.35

1.30

–50

–25 0

TEMPERATURE (°C)

50 100 125

25 75

3406 G06

3406fa

3

LTC34 0 6

INPUT VOLTAGE (V)

10

0.4

0.5

0.7

46

3406 G09

0.3

0.2

23

57

0.1

0

0.6

R

DS(ON)

(Ω)

MAIN
SWITCH

SYNCHRONOUS

SWITCH

LTC34 06 -1.5/LTC 3 4 06 -1.8

UW

TYPICAL PERFOR A CE CHARACTERISTICS

(From Figure1a Except for the Resistive Divider Resistor Values)

Oscillator Frequency vs
Supply Voltage

1.8

1.7

1.6

1.5

1.4

OSCILLATOR FREQUENCY (MHz)

1.3

1.2

0.7

0.6

0.5

0.4

(Ω)

0.3

DS(ON)

R

0.2

0.1

0

2

R

–50

34 56

SUPPLY VOLTAGE (V)

vs Temperature Supply Current vs Supply Voltage Supply Current vs Temperature

DS(ON)

VIN = 4.2V

MAIN SWITCH
SYNCHRONOUS SWITCH

–25 0

VIN = 3.6V

25 75

TEMPERATURE (°C)

3406 G07

VIN = 2.7V

50 100 125

3406 G10

Output Voltage vs Load Current

1.844
VIN = 3.6V

1.834

1.824

1.814

1.804

1.794

OUTPUT VOLTAGE (V)

1.784

1.774

100 900

0

200 300 400 500 600 700 800

LOAD CURRENT (mA)

50

V

= 1.8V

OUT

45

40

35

30

25

20

15

SUPPLY CURRENT (µA)

10

= 0A

I

LOAD

5

0

2

3

4

SUPPLY VOLTAGE (V)

R

) vs Input Voltage

DS(ON

3406 G08

50

VIN = 3.6V

45

= 1.8V

V

OUT

= 0A

I

LOAD

40

35

30

25

20

15

SUPPLY CURRENT (µA)

10

5

0

5

6

3406 G11

–50

–25

0

TEMPERATURE (°C)

50

25

75

100

125

3406 G12

300

250

200

150

100

SWITCH LEAKAGE (nA)

4

Switch Leakage vs Temperature

VIN = 5.5V
RUN = 0V

50

SYNCHRONOUS SWITCH

0

–50

–25 0

TEMPERATURE (°C)

MAIN SWITCH

50 100 125

25 75

3406 G13

Switch Leakage vs Input Voltage

120

RUN = 0V

100

80

60

40

SWITCH LEAKAGE (pA)

20

0

0

SYNCHRONOUS

234

1

INPUT VOLTAGE (V)

SWITCH

MAIN

SWITCH

56

3406 G14

SW

5V/DIV

V

OUT

100mV/DIV

AC COUPLED

200mA/DIV

Burst Mode Operation

I

L

V
I

LOAD

OUT

= 1.8V

= 50mA

4µs/DIVVIN = 3.6V

3406 G15

3406fa

UW

TYPICAL PERFOR A CE CHARACTERISTICS

(From Figure 1a Except for the Resistive Divider Resistor Values)

LTC34 0 6

LTC34 06 -1.5/LTC 3 4 0 6-1. 8

RUN

2V/DIV

V

OUT

2V/DIV

I

LOAD

500mA/DIV

Start-Up from Shutdown

IN

V

OUT

I

LOAD

= 3.6V

= 1.8V

= 600mA

40µs/DIVV

Load Step

V

OUT

100mV/DIV

AC COUPLED

I

L

500mA/DIV

I

LOAD

500mA/DIV

3406 G16

V

OUT

100mV/DIV

AC COUPLED

500mA/DIV

I

LOAD

500mA/DIV

Load Step

I

L

= 3.6V

IN

V

OUT

I

LOAD

= 1.8V

= 0mA TO 600mA

20µs/DIVV

V

OUT

100mV/DIV

AC COUPLED

500mA/DIV

I

LOAD

500mA/DIV

3406 G17

Load Step

I

L

V

OUT

100mV/DIV

AC COUPLED

500mA/DIV

I

LOAD

500mA/DIV

Load Step

I

L

= 3.6V

IN

= 1.8V

V

OUT

I

LOAD

20µs/DIVV

= 50mA TO 600mA

3406 G18

3406 G19

U

= 3.6V

IN

V

= 1.8V

OUT

= 100mA TO 600mA

I

LOAD

20µs/DIVV

UU

PI FU CTIO S

RUN (Pin 1): Run Control Input. Forcing this pin above

1.5V enables the part. Forcing this pin below 0.3V shuts
down the device. In shutdown, all functions are disabled
drawing <1µA supply current. Do not leave RUN floating.

GND (Pin 2): Ground Pin.

SW (Pin 3): Switch Node Connection to Inductor. This pin

connects to the drains of the internal main and synchro­nous power MOSFET switches.

= 3.6V

IN

= 1.8V

V

OUT

= 200mA TO 600mA

I

LOAD

20µs/DIVV

3406 G20

VIN (Pin 4): Main Supply Pin. Must be closely decoupled
to GND, Pin 2, with a 2.2µF or greater ceramic capacitor.

VFB (Pin 5) (LTC3406): Feedback Pin. Receives the feed­back voltage from an external resistive divider across the
output.

V

(Pin 5) (LTC3406-1.5/LTC3406-1.8): Output Volt-

OUT

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

3406fa

5