LTC1911EMS8-1.8 Linear Technology, LTC1911EMS8-1.8 Datasheet

IC DC/DC CONV STP-DWN 1.8V 8MSOP

LTC1911EMS8-1.8

Manufacturer Part Number
LTC1911EMS8-1.8
Description
IC DC/DC CONV STP-DWN 1.8V 8MSOP
Manufacturer
Linear Technology
Type
Step-Down (Buck)r
Datasheet

Specifications of LTC1911EMS8-1.8

Internal Switch(s)
Yes
Synchronous Rectifier
No
Number Of Outputs
1
Voltage - Output
1.8V
Current - Output
250mA
Frequency - Switching
1.5MHz
Voltage - Input
2.7 ~ 5.5 V
Operating Temperature
-40°C ~ 85°C
Mounting Type
Surface Mount
Package / Case
8-MSOP, Micro8™, 8-uMAX, 8-uSOP,
Lead Free Status / RoHS Status
Contains lead / RoHS non-compliant
Power - Output
-
Other names
LTC1911EMS81.8

Available stocks

Company
Part Number
Manufacturer
Quantity
Price
Part Number:
LTC1911EMS8-1.8
Manufacturer:
Linear Technology
Quantity:
135
Part Number:
LTC1911EMS8-1.8
Manufacturer:
LT
Quantity:
10 000
Part Number:
LTC1911EMS8-1.8
Manufacturer:
LINEAR/凌特
Quantity:
20 000
Part Number:
LTC1911EMS8-1.8#PBF
Manufacturer:
LT/凌特
Quantity:
20 000
Part Number:
LTC1911EMS8-1.8#TRPBF
Manufacturer:
LINEAR/凌特
Quantity:
20 000
FEATURES
TYPICAL APPLICATIO
APPLICATIO S
Burst Mode is a registered trademark of Linear Technology Corporation.
*U.S. Patent #6,438,005
, LTC and LT are registered trademarks of Linear Technology Corporation.
Handheld Computers
Cellular Phones
Smart Card Readers
Portable Electronic Equipment
Handheld Medical Instruments
Low Power DSP Supplies
Low Noise Constant Frequency Operation
2.7V to 5.5V Input Voltage Range
No Inductors
Typical Efficiency 25% Higher Than LDOs
Shutdown Disconnects Load from V
Output Voltage: 1.8V 4% or 1.5V 4%
Output Current: 250mA
Low Operating Current: I
Low Shutdown Current: I
Oscillator Frequency: 1.5MHz
Soft-Start Limits Inrush Current at Turn On
Short-Circuit and Overtemperature Protected
Available in an 8-Pin MSOP Package
1-CELL Li-Ion
3-CELL NiMH
*CERAMIC CAPACITOR
OR
2.7V TO 5.5V INPUT
Single Cell Li-Ion to 1.8V DC/DC Converter
U
10 F*
1 F*
IN
IN
= 180 A Typ
= 10 A Typ
1
2
3
4
V
C2
C2
GND
IN
U
LTC1911-1.8
+
SS/SHDN
V
IN
C1
C1
OUT
+
8
6
7
5
1 F*
10 F*
V
I
OUT
OUT
DESCRIPTIO
The LTC
converter that produces a 1.5V or 1.8V regulated output
from a 2.7V to 5.5V input. The part uses switched capaci-
tor fractional conversion to achieve high efficiency over the
entire input range. No inductors are required. Internal cir-
cuitry controls the step-down conversion ratio to optimize
efficiency as the input voltage and load conditions vary.*
Typical efficiency is over 25% higher than that of a linear
regulator.
A unique constant frequency architecture provides a low
noise regulated output as well as lower input noise than
conventional charge pump regulators. High frequency
operation (f
further reduce conducted noise. To optimize efficiency,
the part enters Burst Mode
conditions.
Low operating current (180 A with no load, 10 A in
shutdown) and low external parts count (two 1 F flying
capacitors and two 10 F bypass capacitors) make the
LTC1911 ideally suited for space constrained battery-
powered applications. The part is short-circuit and
overtemperature protected, and is available in an 8-pin
MSOP package.
= 250mA
= 1.8V
1911 TA01
Low Noise, High Efficiency,
®
1911 is a switched capacitor step-down DC/DC
LTC1911-1.5/LTC1911-1.8
Inductorless Step-Down
OSC
= 1.5MHz) simplifies output filtering to
90
80
70
60
50
40
30
2
U
V
100mA
OUT
DC/DC Converter
= 1.8V
3
®
INPUT VOLTAGE (V)
operation under light load
Efficiency
4
IDEAL LDO
250mA
5
1911 G05
6
1
1911f

Related parts for LTC1911EMS8-1.8

LTC1911EMS8-1.8 Summary of contents

Page 1

... Cellular Phones Smart Card Readers Portable Electronic Equipment Handheld Medical Instruments Low Power DSP Supplies , LTC and LT are registered trademarks of Linear Technology Corporation. Burst Mode is a registered trademark of Linear Technology Corporation. *U.S. Patent #6,438,005 U TYPICAL APPLICATIO Single Cell Li-Ion to 1.8V DC/DC Converter LTC1911-1 ...

Page 2

... OUT 0V I 250mA OUT Note 3: Currents flowing into the device are positive polarity. Currents flowing out of the device are negative polarity ORDER PART NUMBER TOP VIEW 8 SS/SHDN LTC1911EMS8-1 LTC1911EMS8-1 OUT – MS8 PART MARKING = 160 C/ W LTMY JA LTNU = unless IN OUT MIN ...

Page 3

W U TYPICAL PERFOR A CE CHARACTERISTICS Input Operating Current vs Input Voltage 210 200 190 180 170 T = – 160 150 INPUT ...

Page 4

LTC1911-1.5/LTC1911-1 TYPICAL PERFOR A CE CHARACTERISTICS Start-Up Time vs Soft-Start Capacitor 100 – 0.1 0 100 ...

Page 5

W SI PLIFIED BLOCK DIAGRA 300k + – 50k + 150k – SHDN + ADJ OFFSET – V REF OVERTEMP DETECT SS/SHDN + 8 – + 600mV LTC1911-1.5/LTC1911-1 ...

Page 6

LTC1911-1.5/LTC1911-1 APPLICATIO S I FOR ATIO General Operation The LTC1911 uses a switch capacitor-based DC/DC con- version to provide the efficiency advantages associated with inductor-based circuits as well as the cost and simplicity advantages of a linear regulator. ...

Page 7

U U APPLICATIO S I FOR ATIO transferred to the parallel combination of C1 and C2 is transferred to the this manner, charge is again OUT transferred from the flying capacitors to the output on both phases ...

Page 8

LTC1911-1.5/LTC1911-1 APPLICATIO S I FOR ATIO 4.7nF capacitor on SS/SHDN results in a 3ms ramp time from 0.6V to 1.9V on the pin OUT ramp time results in an average C only 6mA (see Figure 2). ...

Page 9

U U APPLICATIO S I FOR ATIO To reduce output noise and ripple suggested that a low ESR ( 0.1 ) ceramic capacitor ( greater) be used for C . Tantalum and Aluminum capacitors are not ...

Page 10

LTC1911-1.5/LTC1911-1 APPLICATIO S I FOR ATIO is needed to ensure that minimum capacitance values are met over operating temperature and bias voltage. Table list of ceramic capacitor manufacturers and how to contact them. Table 1. ...

Page 11

... LEAD COPLANARITY (BOTTOM OF LEADS AFTER FORMING) SHALL BE 0.102mm (.004") MAX 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 12

... LTC3412 2. 4MHz, Synchronous Step-Down OUT DC/DC Converter LTC3440 600mA (I ), 2MHz, Synchronous Buck-Boost OUT DC/DC Converter ThinSOT is a trademark of Linear Technology Corporation. Linear Technology Corporation 12 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 FAX: (408) 434-0507 DC/DC Converter with Shutdown and Soft-Start LTC1911-1 ...

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