MIC2145
Micrel
MIC2145
High Efficiency 2.5W Boost Converter
Final
General Description
The MIC2145 is a small size boost switching regulator that
can provide over 2.5W of output power. The input voltage
range is between 2.4V to 16V, making the device suitable for
one-cell Li-Ion and 3- to 4-cell alkaline/NiCad/NiMH applica-
tions. The output voltage of the MIC2145 can be adjusted up
to 16V.
The MIC2145 is well suited for portable, space-sensitive
applications. Its typical 450kHz operation allows small sur-
face mount external components to be used. The MIC2145
has a low quiescent current of 200µA, and a typical shutdown
current of 0.5µA. The MIC2145 is capable of high efficiencies
in a small board area.
The MIC2145 features a low-on resistance internal switch
that allows it to provide over 2.5W of output power. The peak
switch current can be programmed through an external
resistor. This allows the user to set the peak switch current at
the level where maximum efficiency occurs. It also allows the
user to further optimize for efficiency and inductor size by
setting the peak current below the level of inductor saturation.
The MIC2145 is available in an MSOP-8 and 3mm×3mm
MLF™-10L package with an ambient operating temperature
range from –40°C to +85°C.
Part Number
MIC2145BMM
MIC2145BML
Features
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2.4V to 16V input voltage
Output adjustable to 16V
Programmable peak current limit
Soft start
Up to 450kHz switching frequency
0.5µA shutdown current
200µA quiescent current
Capable of 5V/ 500mA output with 3.3V input
Achieves over 85% efficiency
Implements low power BOOST, SEPIC, and FLYBACK
topologies
• MSOP-8 and 3mm×3mm MLF™-10L
Applications
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Flash LED driver
LCD bias supply
White LED driver
DSL bias supply
Local 3V to 5V conversion
Ordering Information
Voltage
Adj
Adj
Ambient Temp. Range
–40°C to +85°C
–40°C to +85°C
Package
8-lead MSOP
3×3 MLF™-10L
Typical Application
V
IN
3.0V to 5.0V
C
IN
10 F/6.3V
1
L1
10 H
D1
EN
PGND
SW
VDD
FB
SGND
5
10V Output
Efficiency
90
V
OUT
10V/150mA
EFFICIENCY (%)
85
80
75
70
65
60
10
V
IN
= 3.0V
100
1000
OUTPUT CURRENT (mA)
4
6
MIC2145BMM
3
C
OUT
10 F/16V
7
RSET
SS
2
8
I Limit
Adjustable Output Boost Converter with Programmable Peak Switch Current
Micrel, Inc. • 1849 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 944-0970 • http://www.micrel.com
May 2003
1
MIC2145
MICREL [ MICREL SEMICONDUCTOR ]
