OMO ElectronicOMO Electronic
Expand menu
Hello, Sign inMy Account
0 Cart

LTC3538EDCB#TRMPBF

P1-P3P4-P6P7-P9P10-P12P13-P15P16-P16
LTC3538
1
3538fb
TYPICAL APPLICATION
FEATURES
APPLICATIONS
DESCRIPTION
The LTC
®
3538 is a highly effi cient, low noise, buck-boost
DC/DC converter that operates from input voltages above,
below, and equal to the output voltage. The topology
incorporated in the IC provides a continuous transfer
function through all operating modes, making the product
ideal for single Lithium Ion or multicell Alkaline or NiMH
applications where the output voltage is within the battery
voltage range.
The LTC3538 is suited for use in Micro Hard Disk Drive
(μHDD) applications with its 800mA current capability. Burst
Mode
®
operation provides high effi ciency at light loads.
The LTC3538 includes two 0.17Ω N-channel and two
0.2Ω P-channel MOSFET switches. Operating frequency
is internally set to 1MHz to minimize solution footprint
while maximizing effi ciency.
Other features include <5μA shutdown current, internal
soft-start, short circuit protection and thermal shutdown.
The LTC3538 is available in a low profi le (0.75mm), ther-
mally enhanced 8-lead (2mm × 3mm) DFN package.
Li-Ion/Polymer to 3.3V at 800mA
■
Regulated Output with Input Voltages Above,
Below, or Equal to the Output
■
800mA Continuous Output Current from a Single
Lithium-Ion/Polymer Cell
■
Single Inductor
■
1.8V to 5.25V V
OUT
Range
■
2.4V to 5.5V V
IN
Range
■
1MHz Fixed Frequency Operation
■
Output Disconnect in Shutdown
■
35μA Quiesecent Current in Burst Mode Operation
■
<5μA Shutdown Current
■
Internal Soft-Start
■
Small, Thermally Enhanced 8-Lead (2mm x 3mm)
DFN package
■
Miniature Hard Disk Drives
■
MP3 Players
■
Digital Cameras
■
Cellular Handsets
■
PDAs, Handheld PC
■
GPS Receivers
, LT, LTC, LTM and Burst Mode are registered trademarks of Linear Technology
Corporation. All other trademarks are the property of their respective owners. Protected by
U.S. Patents including 5481178, 6304066, 6580258, 6166527, 6404251.
SW1
R2
200k
R1
464k
15k
10k
330pF
33pF
C
IN
10μF
V
IN
BURST
SW2
LTC3538
V
IN
2.9V TO 4.2V
L1
3.3
μH
GND
V
OUT
FB
SD
V
C
V
OUT
3.3V
800mA
C
OUT
22μF
PWM BURST
3538 TA01
ON OFF
*
*μP OPEN DRAIN I/O
Effi ciency vs V
IN
V
IN
(V)
2.4
95
85
3.9 4.9
3538 TA01b
2.9 3.4 4.4 5.4
90
80
EFFICIENCY (%)
100
V
OUT
= 3.3V
I
LOAD
= 200mA
800mA Synchronous
Buck-Boost
DC/DC Converter
LTC3538
2
3538fb
PIN CONFIGURATION
ELECTRICAL CHARACTERISTICS
ABSOLUTE MAXIMUM RATINGS
V
IN
,V
OUT
Voltage .......................................... –0.3V to 6V
SW1,SW2 Voltage
DC ............................................................ –0.3V to 6V
Pulsed < 100ns ........................................ –0.3V to 7V
BURST, FB, VC Voltage ................................. –0.3V to 6V
Operating Temperature (Note 2)............... –40°C to 85°C
Maximum Junction Temperature (Note 3)............. 125°C
Storage Temperature Range ................... –65°C to 125°C
(Note 1)
PARAMETER CONDITIONS MIN TYP MAX UNITS
Input Voltage
●
2.4 5.5 V
Feedback Voltage (Note 4)
●
0.980 1.00 1.020 V
Feedback Input Current (Note 4) 1 50 nA
V
IN
Quiescent Current – Shutdown V
C
= 0V, Not Including Switch Leakage 1.5 5 μA
V
IN
Quiescent Current – Active FB = 0.8V 1 1.8 mA
V
IN
Quiescent Current – Sleep FB = 1.2V, BURST = V
IN
35 60 μA
NMOS Switch Leakage Switches B and C 0.1 7 μA
PMOS Switch Leakage Switches A and D 0.1 10 μA
NMOS Switch On-Resistance Switches B and C 0.17 Ω
PMOS Switch On-Resistance Switches A and D 0.2 Ω
Input Current Limit
●
1.4 2 A
Reverse Current Limit 0.5 A
Burst Mode Operational Peak Current 0.9 A
Maximum Duty Cycle Boost (%Switch C On)
Buck (% Switch A On)
Buck (% Switch D On)
●
●
●
70
100
100
88 %
%
%
TOP VIEW
V
IN
SW1
SW2
V
OUT
FB
VC
GND
BURST
DCB PACKAGE
8-LEAD (2mm × 3mm) PLASTIC DFN
9
3
4
2
1
6
5
7
8
T
JMAX
= 125°C
θ
JA
= 75°C/W 4-LAYER BOARD, θ
JC
= 13.5°C/W
EXPOSED PAD (PIN 9) IS GND, MUST BE SOLDERED TO PCB
The ● denotes the specifi cations which apply over the full operating
temperature range, otherwise specifi cations are at T
A
= 25°C. V
IN
= V
OUT
= 3.6V, BURST = 0V, unless otherwise noted.
ORDER INFORMATION
LEAD FREE FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE
LTC3538EDCB#PBF LTC3538EDCB#TRPBF LCRB 8-Lead (2mm × 3mm) Plastic DFN –40°C to 85°C
LEAD BASED FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE
LTC3538EDCB LTC3538EDCB#TR LCRB 8-Lead (2mm × 3mm) Plastic DFN –40°C to 85°C
Consult LTC Marketing for parts specifi ed with wider operating temperature ranges.
For more information on lead free part marking, go to: http://www.linear.com/leadfree/
For more information on tape and reel specifi cations, go to: http://www.linear.com/tapeandreel/
LTC3538
3
3538fb
LOAD CURRENT (mA)
0.1 1 10 100 1000
0.1
1
10
100
1000
EFFICIENCY (%)
POWER LOSS (mW)
100
80
60
40
20
0
90
70
50
30
10
3538 G02
Burst Mode
OPERATION
POWER LOSS
FIXED FREQUENCY
POWER LOSS BURST
FIXED FREQUENCY
LOAD CURRENT (mA)
0.1 1 10 100 1000
EFFICIENCY (%)
100
80
60
40
20
10
90
70
50
30
3538 G01
V
IN
= 2.7V
V
IN
= 3.6V
V
IN
= 4.2V
Burst Mode
OPERATION
PARAMETER CONDITIONS MIN TYP MAX UNITS
Minimum Duty Cycle FB = 1.2V
●
0%
Frequency Accuracy
●
0.8 1 1.2 MHz
Internal Soft-Start Time 1.5 ms
Error Amp A
VOL
80 dB
Error Amp Source Current V
C
= 1.5V, FB = OV –13 μA
Error Amp Sink Current V
C
= 1.5V, FB = 1.2V 130 μA
V
C
Shutdown Threshold (Off) IC is Disabled
●
0.25 V
V
C
Output Current in Shutdown V
C
= GND –1 –3 μA
BURST Threshold (High)
●
1.4 V
BURST Threshold (Low)
●
0.4 V
BURST Input Current V
BURST
= 3.6V 0.1 1 μA
Note 1: Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.
Note 2: The LTC3538 is guaranteed to meet performance specifi cations
from 0°C to 85°C. Specifi cations over –40°C to 85°C operating
temperature range are assured by design, characterization and correlation
with statistical process controls.
Note 3: This IC includes over-temperature protection that is intended
to protect the device during momentary overload conditions. Junction
temperature will exceed 125°C when over-temperature protection is active.
Continuous operation above the specifi ed maximum operating junction
temperature may result in device degradation or failure.
Note 4: The IC is tested in a feedback loop to make the measurement.
TYPICAL PERFORMANCE CHARACTERISTICS
Li-Ion to 3.3V Effi ciency
Effi ciency and Power Loss vs
Load Current
Switch Pins Before Entering
Boost Mode
ELECTRICAL CHARACTERISTICS
The ● denotes the specifi cations which apply over the full operating
temperature range, otherwise specifi cations are at T
A
= 25°C. V
IN
= V
OUT
= 3.6V, unless otherwise noted.
T
A
= 25°C unless otherwise noted
50ns/DIV
SW1
2V/DIV
SW2
2V/DIV
3538 G03
V
IN
= 2.9V
V
OUT
= 3.3V AT 500mA
P1-P3P4-P6P7-P9P10-P12P13-P15P16-P16

LTC3538EDCB#TRMPBF

Mfr. #:
Buy LTC3538EDCB#TRMPBF
Manufacturer:
Analog Devices / Linear Technology
Description:
Switching Voltage Regulators 800mA, 1MHz Wide Input Voltage Synch Buck-Boost DC/DC Converter in DFN-8
Lifecycle:
New from this manufacturer.
Delivery:
DHL FedEx Ups TNT EMS
Payment:
T/T Paypal Visa MoneyGram Western Union

Products related to this Datasheet