LTC1622IS8#TR Linear Technology, LTC1622IS8#TR Datasheet

IC CTRLR DC/DC STEP DOWN 8SOIC

LTC1622IS8#TR

Manufacturer Part Number
LTC1622IS8#TR
Description
IC CTRLR DC/DC STEP DOWN 8SOIC
Manufacturer
Linear Technology
Type
Step-Down (Buck)r
Datasheet

Specifications of LTC1622IS8#TR

Internal Switch(s)
No
Synchronous Rectifier
No
Number Of Outputs
1
Voltage - Output
0.8 ~ 9.8 V
Current - Output
1A
Frequency - Switching
110kHz ~ 550kHz
Voltage - Input
2 ~ 10 V
Operating Temperature
-45°C ~ 85°C
Mounting Type
Surface Mount
Package / Case
8-SOIC (3.9mm Width)
Lead Free Status / RoHS Status
Contains lead / RoHS non-compliant
Power - Output
-

Available stocks

Company
Part Number
Manufacturer
Quantity
Price
Company:
Part Number:
LTC1622IS8#TRLTC1622IS8
Manufacturer:
LINEAR/凌特
Quantity:
20 000
Company:
Part Number:
LTC1622IS8#TR
Quantity:
235
Company:
Part Number:
LTC1622IS8#TRLTC1622IS8TRPBF
Manufacturer:
LT
Quantity:
4 830
FEATURES
TYPICAL APPLICATIO
APPLICATIO S
Burst Mode and OPTI-LOOP are a trademarks of Linear Technology Corporation.
, LTC and LT are registered trademarks of Linear Technology Corporation.
C1: TAIYO YUDEN CERAMIC EMK325BJ106MNT
C2: SANYO POSCAP 6TPA47M
D1: INTERNATIONAL RECTIFIER IR10BQ015
High Efficiency
Constant Frequency 550kHz Operation
V
Multiampere Output Currents
OPTI-LOOP
Selectable, Burst Mode Operation
Low Dropout Operation: 100% Duty Cycle
Synchronizable up to 750kHz
Current Mode Operation for Excellent Line and Load
Transient Response
Low Quiescent Current: 350 A
Shutdown Mode Draws Only 15 A Supply Current
Available in 8-Lead MSOP
1- or 2-Cell Li-Ion Powered Applications
Cellular Telephones
Wireless Modems
Portable Computers
Distributed 3.3V, 2.5V or 1.8V Power Systems
Scanners
Battery-Powered Equipment
IN
1.9% Reference Accuracy
R1
10k
C3
220pF
470pF
Range: 2V to 10V
Figure 1. High Efficiency Step-Down Converter
2
4
I
RUN/SS
TH
TM
LTC1622
SYNC/MODE
8
3
Compensation Minimizes C
V
V
IN
FB
SENSE
U
PDRV
GND
1
7
5
6
2.5V TO 8.5V
V
IN
Si3443DV
R2
0.03
L1: MURATA LQN6C-4R7
R2: DALE WSL-1206 0-03
D1
IR10BQ015
U
4.7 H
L1
R3
159k
R4
75k
C1
10 F
10V
OUT
+
1622 F01a
C2
47 F
6V
V
2.5V
1.5A
OUT
DESCRIPTIO
The LTC
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 350 A 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 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
15 A.
Current Mode Step-Down
®
1622 is a constant frequency current mode step-
100
90
80
70
60
50
40
Efficiency vs Load Current with
Burst Mode Operation Enabled
1
V
IN
Low Input Voltage
= 3.3V
DC/DC Controller
U
10
LOAD CURRENT (mA)
V
V
IN
IN
= 4.2V
= 8.4V
100
V
R
TM
OUT
SENSE
operation. Burst Mode
1000
= 2.5V
V
IN
= 0.03
= 6V
1622 F01b
5000
LTC1622
1

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LTC1622IS8#TR Summary of contents

Page 1

... Li-Ion Powered Applications Cellular Telephones Wireless Modems Portable Computers Distributed 3.3V, 2.5V or 1.8V Power Systems Scanners 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. U TYPICAL APPLICATIO V IN 2. ...

Page 2

LTC1622 ABSOLUTE MAXIMUM Input Supply Voltage (V ).........................– 0.3V to 10V IN RUN/SS Voltage .......................................– 0.3V to 2.4V SYNC/MODE Voltage ................................. – 0. – SENSE Voltage .......................................... 2. PDRV Peak Output Current (< ...

Page 3

ELECTRICAL CHARACTERISTICS temperature range, otherwise specifications are at T SYMBOL PARAMETER PDRV t Gate Drive Rise Time r PDRV t Gate Drive Fall Time f V Maximum Current Sense Voltage SENSE(MAX) Note 1: Absolute Maximum Ratings are those values beyond ...

Page 4

LTC1622 W U TYPICAL PERFORMANCE CHARACTERISTICS Efficiency vs Load Current for Figure 1 with Burst Mode Operation Defeated 100 ...

Page 5

U U FUNCTIONAL DIAGRA V IN BURST DEFEAT SYNC/ 5 MODE OSC – 0. FREQ SHIFT 0.8V REFERENCE RUN/SS V REF 0.8V UVLO TRIP = 1.97V 6 GND ...

Page 6

LTC1622 U OPERATIO (Refer to Functional Diagram) the I pin will drop. When the 0.12V, the sleep signal goes high, turning off the external MOSFET. The sleep signal goes low when the I rises above 0.22V and ...

Page 7

U U APPLICATIONS INFORMATION The basic LTC1622 application circuit is shown in Figure 1. External component selection is driven by the load requirement and begins with the selection of L and R Next, the Power MOSFET and the output diode ...

Page 8

LTC1622 U U APPLICATIONS INFORMATION preferred at high switching frequencies, so design goals can concentrate on copper loss and preventing saturation. Ferrite core materials saturate “hard,” which means that the inductance collapses abruptly when the peak design current is exceeded. ...

Page 9

U U APPLICATIONS INFORMATION The allowable forward voltage drop in the diode is calcu- lated from the maximum short-circuit current as MAX where P is the allowable power dissipation and will be D determined ...

Page 10

LTC1622 U U APPLICATIONS INFORMATION 101 V REF 100 V 99 ITH 2.0 2.2 2.4 2.6 INPUT VOLTAGE (V) Figure 3. Line Regulation of V the maximum current sense voltage that sets the maxi- mum output ...

Page 11

U U APPLICATIONS INFORMATION 2 Transition Loss = 3 O(MAX) Other losses including C and C IN losses, and inductor core losses, generally account for less than 2% total additional loss. Run/Soft-Start Function The RUN/SS pin is ...

Page 12

LTC1622 U U APPLICATIONS INFORMATION down to 2.7V. Let’s assume that the MOSFET dissipation limited 250mW and its thermal resistance C/W. Hence the junction temperature at T will be 37.5 C ...

Page 13

U TYPICAL APPLICATIONS LTC1622 1.8V/1.5A Regulator with Burst Mode Operation Disabled V IN 2.5V TO 8.5V 1 SENSE LTC1622 10K RUN/ 220pF SS C4 560pF C1: AVX TPSD476M016R0150 C2: AVX TPSD227M006R0100 ...

Page 14

LTC1622 U TYPICAL APPLICATIONS LTC1622 2.5V/3A Regulator with External Frequency Synchronization R1 10k C3 220pF C1: AVX TPSD476M016R0150 C2: AVX TPSD107M010R0065 D1: MOTOROLA MBR320T3 D2 1N4818 R1 47k C3 470pF C4 0.1 F C1: AVX TPSD476M016R0150 C2: AVX TPSD107M010R0080 D1: ...

Page 15

... FLASH SHALL NOT EXCEED 0.010" (0.254mm) PER SIDE Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no represen- tation that the interconnection of its circuits as described herein will not infringe on existing patent rights. ...

Page 16

... Low Supply Voltage Range: 2.65V to 8V, 0.5A Antiphase Drive, 3.5V V 36V, Protection IN 6-Lead SOT-23, 2.5V V 9.8V, 550kHz IN Burst Mode Operation, Protection, 3.5V V sn1622 1622fs LT/TP 1001 4K • PRINTED IN USA LINEAR TECHNOLOGY CORPORATION 1998 = 4.2V = 0.025 1000 1622 TA05b 1 1622 TA06b IN 6V ...

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