Name: LTC3407EDD-2
SKU: LTC3407EDD-2
Price: 8.20608 USD
Availability: InStock

LTC3407-2

sn34072 34072fs

APPLICATIO S

FEATURES

TYPICAL APPLICATIO

DESCRIPTIO

■

PDAs/Palmtop PCs

■

Digital Cameras

■

Cellular Phones

■

Portable Media Players

■

PC Cards

■

Wireless and DSL Modems

■

High Efficiency: Up to 95%

■

Very Low Quiescent Current: Only 40µA

■

2.25MHz Constant Frequency Operation

■

High Switch Current: 1.2A on Each Channel

■

No Schottky Diodes Required

■

Low R

DS(ON)

Internal Switches: 0.35Ω

■

Current Mode Operation for Excellent Line

and Load Transient Response

■

Short-Circuit Protected

■

Low Dropout Operation: 100% Duty Cycle

■

Ultralow Shutdown Current: I

< 1µA

■

Output Voltages from 5V down to 0.6V

■

Power-On Reset Output

■

Externally Synchronizable Oscillator

■

Small Thermally Enhanced MSOP and 3mm × 3mm

DFN Packages

Dual Synchronous, 800mA,

2.25MHz Step-Down

DC/DC Regulator

The LTC

3407-2 is a dual, constant frequency, synchro-

nous step down DC/DC converter. Intended for low power

applications, it operates from 2.5V to 5.5V input voltage

range and has a constant 2.25MHz switching frequency,

allowing the use of tiny, low cost capacitors and inductors

with a profile ≤1.2mm. Each output voltage is adjustable

from 0.6V to 5V. Internal synchronous 0.35Ω, 1.2A power

switches provide high efficiency without the need for

external Schottky diodes.

A user selectable mode input is provided to allow the user

to trade-off noise ripple for low power efficiency. Burst

Mode

operation provides high efficiency at light loads,

while Pulse Skip Mode provides low noise ripple at light

loads.

To further maximize battery life, the P-channel MOSFETs

are turned on continuously in dropout (100% duty cycle),

and both channels draw a total quiescent current of only

40µA. In shutdown, the device draws <1µA.

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

Burst Mode is a registered trademark of Linear Technology Corporation.

LTC3407-2 Efficiency Curve

Figure 1. 2.5V/1.8V at 800mA Step-Down Regulators

RUN2 V

= 2.5V*

TO 5.5V

OUT2

= 2.5V

AT 800mA

OUT1

= 1.8V

AT 800mA

RUN1

POR

SW1

FB1

GND

FB2

SW2

MODE/SYNC

LTC3407-2

10µF

100k

RESET

C4, 22pFC5, 22pF

2.2µH

887k

604k

301k

280k

10µF

3407 TA01

C1, C2, C3: TAIYO YUDEN JMK316BJ106ML L1, L2: MURATA LQH32CN2R2M33

OUT

CONNECTED TO V

FOR V

≤ 2.8V

LOAD CURRENT (mA)

EFFICIENCY (%)

100

10 100 1000

3407 TA02

= 3.3V

Burst Mode OPERATION

NO LOAD ON OTHER CHANNEL

2.5V

1.8V

LTC3407-2

sn34072 34072fs

TOP VIEW

DD PACKAGE

10-LEAD (3mm × 3mm) PLASTIC DFN

DD PIN 11, EXPOSED PAD: PGND

MUST BE CONNECTED TO GND

FB2

RUN2

POR

SW2

MODE/

SYNC

FB1

RUN1

SW1

GND

Voltages.................................................–0.3V to 6V

FB1

, V

FB2

, RUN1, RUN2

Voltages ..................................... –0.3V to V

+ 0.3V

MODE/SYNC Voltage ...................... – 0.3V to V

+ 0.3V

SW1, SW2 Voltage ......................... –0.3V to V

+ 0.3V

POR Voltage ................................................–0.3V to 6V

ABSOLUTE AXI U RATI GS

(Note 1)

ELECTRICAL CHARACTERISTICS

The ● denotes the specifications which apply over the full operating

temperature range, otherwise specifications are at T

= 25°C. V

= 3.6V, unless otherwise specified. (Note 2)

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

Operating Voltage Range ● 2.5 5.5 V

Feedback Pin Input Current ● 30 nA

Feedback Voltage (Note 3) 0°C ≤ T

≤ 85°C 0.588 0.6 0.612 V

–40°C ≤ T

≤ 85°C ● 0.585 0.6 0.612 V

∆V

LINE REG

Reference Voltage Line Regulation V

= 2.5V to 5.5V (Note 3) 0.3 0.5 %/V

∆V

LOAD REG

Output Voltage Load Regulation (Note 3) 0.5 %

Input DC Supply Current

Active Mode V

FB1

= V

FB2

= 0.5V 700 950 µA

Sleep Mode V

FB1

= V

FB2

= 0.63V, MODE/SYNC = 3.6V 40 60 µA

Shutdown RUN = 0V, V

= 5.5V, MODE/SYNC = 0V 0.1 1 µA

OSC

Oscillator Frequency V

FBX

= 0.6V ● 1.8 2.25 2.7 MHz

SYNC

Synchronization Frequency 2.25 MHz

LIM

Peak Switch Current Limit V

= 3V, V

FBX

= 0.5V, Duty Cycle <35% 0.95 1.2 1.6 A

DS(ON)

Top Switch On-Resistance (Note 6) 0.35 0.45 Ω

Bottom Switch On-Resistance (Note 6) 0.30 0.45 Ω

SW(LKG)

Switch Leakage Current V

= 5V, V

RUN

= 0V, V

FBX

= 0V 0.01 1 µA

Ambient Operating Temperature

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

Junction Temperature (Note 5)............................. 125°C

Storage Temperature Range ................. – 65°C to 125°C

Lead Temperature (Soldering, 10 sec)

LTC3407-2EMSE only ...................................... 300°C

Reflow Peak Body Temperature ............................ 260°C

ORDER PART

NUMBER

DD PART MARKING

JMAX

= 125°C, θ

= 45°C/W, θ

= 10°C/W

LBFB

LTC3407EDD-2

PACKAGE/ORDER I FOR ATIO

UUW

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

ORDER PART

NUMBER

MSE PART MARKING

JMAX

= 125°C, θ

= 45°C/W, θ

= 10°C/W

LTBDZ

LTC3407EMSE-2

TOP VIEW

FB1

RUN1

SW1

GND

FB2

RUN2

POR

SW2

MODE/

SYNC

MSE PACKAGE

10-LEAD PLASTIC MSOP

MSE PIN 11, EXPOSED PAD: PGND

MUST BE CONNECTED TO GND

LTC3407-2

sn34072 34072fs

TYPICAL PERFOR A CE CHARACTERISTICS

Load Step

Burst Mode Operation

Pulse Skipping Mode

Efficiency vs Input Voltage

Oscillator Frequency vs Supply

Voltage

Oscillator Frequency vs

Temperature

Note 1: Absolute Maximum Ratings are those values beyond which the life

of a device may be impaired.

Note 2: The LTC3407-2E is guaranteed to meet specified performance

from 0°C to 70°C. Specifications over the – 40°C and 85°C operating

temperature range are assured by design, characterization and correlation

with statistical process controls.

Note 3: The LTC3407-2 is tested in a proprietary test mode that connects

to the output of the error amplifier.

Note 4: Dynamic supply current is higher due to the internal gate charge

being delivered at the switching frequency.

Note 5: T

is calculated from the ambient T

and power dissipation P

according to the following formula: T

= T

+ (P

• θ

Note 6: The DFN switch on-resistance is guaranteed by correlation to

wafer level measurements.

ELECTRICAL CHARACTERISTICS

The ● denotes the specifications which apply over the full operating

temperature range, otherwise specifications are at T

= 25°C. V

= 3.6V, unless otherwise specified. (Note 2)

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

POR Power-On Reset Threshold V

FBX

Ramping Up, MODE/SYNC = 0V 8.5 %

FBX

Ramping Down, MODE/SYNC = 0V –8.5 %

Power-On Reset On-Resistance 100 200 Ω

Power-On Reset Delay 262,144 Cycles

RUN

RUN Threshold ● 0.3 1 1.5 V

RUN

RUN Leakage Current ● 0.01 1 µA

2.5

2.4

2.3

2.2

2.1

2.0

FREQUENCY (MHz)

–2

–4

–6

–8

–10

FREQUENCY DEVIATION (%)

SUPPLY VOLTAGE (V)

3407 G06

456

INPUT VOLTAGE (V)

3407 G04

3407 G01 3407 G02 3407 G03

456

TEMPERATURE (°C)

–50 25 75

3407 G05

–25 0

50 100 125

100

EFFICIENCY (%)

= 3.6V

OUT

= 1.8V

LOAD

= 100mA

CIRCUIT OF FIGURE 1

= 3.6V

OUT

= 1.8V

LOAD

= 20mA

CIRCUIT OF FIGURE 1

= 3.6V

OUT

= 1.8V

LOAD

= 80mA TO 800mA

CIRCUIT OF FIGURE 1

OUT

= 1.8V

Burst Mode OPERATION

CIRCUIT OF FIGURE 1

800mA

10mA

100mA

1mA

5V/DIV

OUT

100mV/DIV

200mA/DIV

5V/DIV

OUT

10mV/DIV

200mA/DIV

OUT

200mV/DIV

500mA/DIV

LOAD

500mA/DIV

2µs/DIV 1µs/DIV 20µs/DIV

= 3.6V

= 25°C unless other wise specified.

Part #	LTC3407EDD-2
Description	IC REG BCK SYNC ADJ 0.8A 10DFN
Category	IC
Availability	In Stock
Qty	1

LTC3407EDD-2

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