LTC1622 판매점 - Low Input Voltage Current Mode Step-Down DC/DC Controller

LTC1622 반도체 회로 부품 판매점

Low Input Voltage Current Mode Step-Down DC/DC Controller

Linear Technology

FEATURES

s High Efficiency

s Constant Frequency 550kHz Operation

s VIN Range: 2V to 10V

s Multiampere Output Currents

s OPTI-LOOPTM Compensation Minimizes COUT

s Selectable, Burst Mode Operation

s Low Dropout Operation: 100% Duty Cycle

s Synchronizable up to 750kHz

s Current Mode Operation for Excellent Line and Load

Transient Response

s Low Quiescent Current: 350µA

s Shutdown Mode Draws Only 15µA Supply Current

s ±1.9% Reference Accuracy

s Available in 8-Lead MSOP

APPLICATIO S

s 1- or 2-Cell Li-Ion Powered Applications

s Cellular Telephones

s Wireless Modems

s Portable Computers

s Distributed 3.3V, 2.5V or 1.8V Power Systems

s Scanners

s Battery-Powered Equipment

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

Burst Mode and OPTI-LOOP are a trademarks of Linear Technology Corporation.

LTC1622

Low Input Voltage

Current Mode Step-Down

DC/DC Controller

DESCRIPTIO

The LTC®1622 is a constant frequency current mode step-

down DC/DC controller providing excellent AC and DC load

and line regulation. The device incorporates an accurate

undervoltage feature that shuts the LTC1622 down when

the input voltage falls below 2V.

The LTC1622 boasts a ±1.9% output voltage accuracy and

consumes only 350µA of quiescent current. For applica-

tions where efficiency is a prime consideration and the

load current varies from light to heavy, the LTC1622 can

be configured for Burst ModeTM operation. Burst Mode

operation enhances low current efficiency and extends

battery run time. Burst Mode operation is inhibited during

synchronization or when the SYNC/MODE pin is pulled low

to reduce noise and possible RF interference.

High constant operating frequency of 550kHz allows the

use of a small inductor. The device can also be synchro-

nized up to 750kHz for special applications. The high

frequency operation and the available 8-lead MSOP pack-

age create a high performance solution in an extremely

small amount of PCB area.

To further maximize the life of the battery source, the

P-channel MOSFET is turned on continuously in dropout

(100% duty cycle). In shutdown, the device draws a mere

15µA.

TYPICAL APPLICATIO

VIN

2.5V TO 8.5V

10k

220pF

ITH

VIN

SENSE–

PDRV

LTC1622

SYNC/MODE

470pF

RUN/SS

VFB

GND

0.03Ω

Si3443DV L1

4.7µH

IR10BQ015

10µF

10V

159k +

75k

VOUT

2.5V

1.5A

47µF

C1: TAIYO YUDEN CERAMIC EMK325BJ106MNT L1: MURATA LQN6C-4R7

C2: SANYO POSCAP 6TPA47M

R2: DALE WSL-1206 0-03Ω

D1: INTERNATIONAL RECTIFIER IR10BQ015

1622 F01a

Figure 1. High Efficiency Step-Down Converter

Efficiency vs Load Current with

Burst Mode Operation Enabled

100

VIN = 4.2V

90 VIN = 3.3V

VIN = 6V

70 VIN = 8.4V

VOUT = 2.5V

RSENSE = 0.03Ω

10 100 1000

LOAD CURRENT (mA)

5000

1622 F01b

LTC1622

ABSOLUTE MAXIMUM RATINGS (Note 1)

Input Supply Voltage (VIN).........................– 0.3V to 10V

RUN/SS Voltage .......................................– 0.3V to 2.4V

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

SENSE – Voltage .......................................... 2.4V to VIN

PDRV Peak Output Current (< 10µs) ......................... 1A

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

Operating Temperature Range

Commercial ............................................ 0°C to 70°C

Industrial ........................................... – 45°C to 85°C

Junction Temperature (Note 2) ............................. 125°C

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

PACKAGE/ORDER INFORMATION

SENSE– 1

ITH 2

VFB 3

RUN/SS 4

TOP VIEW

8 VIN

7 PDRV

6 GND

5 SYNC/MODE

MS8 PACKAGE

8-LEAD PLASTIC MSOP

TJMAX = 125°C, θJA = 250°C/ W

ORDER PART

NUMBER

LTC1622CMS8

MS8 PART MARKING

LTDB

SENSE– 1

ITH 2

VFB 3

RUN/SS 4

TOP VIEW

8 VIN

7 PDRV

6 GND

5 SYNC/MODE

S8 PACKAGE

8-LEAD PLASTIC SO

TJMAX = 125°C, θJA = 150°C/ W

Consult factory for Military grade parts.

ORDER PART

NUMBER

LTC1622CS8

LTC1622IS8

S8 PART MARKING

1622

1622I

ELECTRICAL CHARACTERISTICS The q denotes specifications which apply over the full operating

temperature range, otherwise specifications are at TA = 25°C. VIN = 4.2V

SYMBOL PARAMETER

CONDITIONS

MIN TYP MAX

IVFB Feedback Current

VFB Regulated Feedback Voltage

(Note 3) VFB = 0.8V

(Note 3) Commercial Grade

(Note 3) Industrial Grade

10 70

q 0.785 0.8 0.815

q 0.780 0.8 0.820

VOVL

∆VOSENSE

VLOADREG

Output Overvoltage Lockout

Reference Voltage Line Regulation

Output Voltage Load Regulation

VRUN/SS

Input DC Supply Current

Burst Mode Inhibited

Sleep Mode

Shutdown

RUN/SS Threshold

Referenced to Nominal VOUT

VIN = 4.2V to 8.5V (Note 3)

Measured in Servo Loop; VITH = 0.2V to 0.625V

Measured in Servo Loop; VITH = 0.9V to 0.625V

(Note 4)

VIN = 2.3V

VITH = 0V, VSYNC/MODE = 2.4V

VRUN/SS = 0V

VRUN/SS = 0V, VIN = VUVLO – 0.1V

Commercial Grade

Industrial Grade

0.4

0.3

7.5 10.5

0.04 0.08

0.3 0.5

– 0.3 – 0.5

450

350 400

15 30

4 10

0.7 0.9

0.7 1.0

IRUN/SS

fOSC

Soft-Start Current Source

Oscillator Frequency

VSYNC/MODE SYNC/MODE Threshold

VUVLO

Undervoltage Lockout

VRUN/SS = 0V

VFB = 0.8V

VFB = 0V

VSYNC/MODE Ramping Down

VIN Ramping Down

VIN Ramping Up

1 2.5 5

475 550 625

75 110 140

1 1.5

q 1.55 1.92

2.3

1.97 2.36

UNITS

%/V

µA

kHz

PDF 파일 내의 페이지 : 총 16 페이지

제조업체: Linear Technology

( linear )

LTC1622 controller

데이터시트 다운로드 :

[ LTC1622.PDF ]

[ LTC1622 다른 제조사 검색 ]

국내 전력반도체 판매점

상호 : 아이지 인터내셔날

전화번호 : 051-319-2877

[ 홈페이지 ]

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전력반도체 문의 : 010-3582-2743

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LTC1622 반도체 회로 부품 판매점

Low Input Voltage Current Mode Step-Down DC/DC Controller

국내 전력반도체 판매점

일반적인 전자부품 판매점

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