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Boost Converter. MIC2145 Datasheet |
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MIC2145
Micrel, Inc.
MIC2145
High Efficiency 2.5W Boost Converter
General Description
Features
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.
• 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
• Flash LED driver
• LCD bias supply
• White LED driver
• DSL bias supply
• Local 3V to 5V conversion
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.
Ordering Information
Part Number
Standard
Pb-Free
MIC2145BMM MIC2145YMM
MIC2145BML MIC2145YML
Voltage
Adj
Adj
Ambient
Temp. Range
–40°C to +85°C
–40°C to +85°C
Package
8-lead MSOP
10-lead MLF™
Typical Application
VIN
3.0V to 5.0V
CIN
10µF/6.3V
I Limit
L1
10µH
1
EN
5
SW
4
PGND
6
VDD
MIC2145BMM
3
RSET
FB 7
D1
2 SS
SGND 8
VOUT
10V/150mA
COUT
10µF/16V
10V Output
Efficiency
90
85
80
75
70
65
VIN = 3.0V
6010 100 1000
OUTPUT CURRENT (mA)
Adjustable Output Boost Converter with Programmable Peak Switch Current
MLF and MicroLeadFrame are trademarks of Amkor Technologies, Inc.
Micrel, Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com
April 2005
1 M9999-042205
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MIC2145
Pin Configuration
EN 1
SS 2
RSET 3
PGND 4
8 SGND
7 FB
6 VDD
5 SW
8-Lead MSOP (MM)
Micrel, Inc.
EN
SS
RSET
PGND
PGND
1
2
3
4
5
10 SGND
9 FB
8 VDD
7 SW
6 SW
3mm×3mm MLF-10L (ML)
Pin Description
Pin Number
MSOP
1
Pin Number
MLF
1
22
33
4 4, 5
5 6, 7
68
79
8 10
Pin Name
EN
SS
RSET
PGND
SW
VDD
FB
SGND
Pin Function
Enable (Input): Logic high (≥1.5V) enables regulator. Logic low (≤0.7V)
shuts down regulator. Do not float.
Soft Start Capacitor (External Component): Connect external capacitor to
ground to control the rise time of the output voltage.
Current Limit (External Component): Sets peak current limit of the internal
power MOSFET using an external resistor.
Power Ground (Return): Internal power MOSFET source.
Switch Node (Input): Internal power MOSFET drain.
Supply (Input): +2.4V to +16V for internal circuitry.
Feedback (Input): Output voltage sense node.
Small Signal Ground (Return): Ground
M9999-042205
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April 2005
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MIC2145
Absolute Maximum Ratings (Note 1)
Supply Voltage (VDD) .................................................... 18V
Switch Voltage (VSW) .................................................... 18V
Feedback Voltage (VFB) ................................................ 18V
Switch Current (ISW) ........................................................ 2A
Enable Voltage(VEN), Note 5 ........................................ 18V
RSET Voltage (VRSET) .................................................... 6V
ESD Rating, Note 3 ...................................................... 2kV
Ambient Storage Temperature(TS) .......... –65°C to +150°C
Micrel, Inc.
Operating Ratings (Note 2)
Supply Voltage (VDD) ....................................... 2.4V to 16V
Switch Voltage (VSW) .................................................... 16V
Ambient Temperature (TA) ......................... –40°C to +85°C
Junction Temperature (TJ) ....................... –40°C to +125°C
Package Thermal Resistance MSOP
θJA (MSOP-8) .................................................... 206°C/W
θJA (3mm×3mm MLF-10) .................................... 60°C/W
Electrical Characteristics (Note 6)
VDD = 10V, VOUT = 10V, IOUT = 100mA; TJ =25°C, unless otherwise noted, bold values indicate –40°C ≤ TJ ≤ 125°C.
Parameter
Condition
Min Typ Max
Supply Voltage
2.4 16
Shutdown Current
Quiescent Current
Feedback Voltage Reference
EN = 0.3V, VDD = 10V, VFB=1.35V
EN = VDD, VDD = 10V, VFB = 1.35V
(±2%)
0.5 5
200 300
1.058 1.08 1.102
(±3%)
1.048
1.112
Comparator Hysteresis
18
Feedback Input Current
Peak Current Limit
Current Limit Comparator
Propagation Delay
VFB=1.35V
RSET=200Ω, VDD = 3.6V, Note 4
RSET=1kΩ, VDD = 10V, Note 4
40
0.8
0.9
500
Switch On-Resistance
Maximum Off Time
ISW = 150mA, VDD = 3.0V
ISW = 1.2A, VDD = 10V
500
250
1000
750
400
Enable Input Voltage
Logic Low (turn-off)
1.1 0.7
Logic High (turn-on)
1.5 1.1
Enable Input Current
Soft Start Current
VEN = 0V
VEN = 2V
VEN = 2V, VDD=3.0V
–1 0.01
1
–1 0.01
1
–8 –12 –16
Note 1.
Note 2.
Note 3.
Note 4.
Note 5.
Note 6.
Exceeding the absolute maximum rating may damage the device.
The device is not guaranteed to function outside its operating rating.
Devices are ESD sensitive. Handling precautions recommended. Human body model, 1.5KΩ in series with 100pF.
The current is measured in a DC mode. Actual peak switching current will be higher due to internal propagation delay of the circuit.
VEN ≤ VDD.
Specification for packaged product only.
Units
V
µA
µA
V
V
mV
nA
A
A
ns
mΩ
mΩ
ns
V
V
µA
µA
µA
April 2005
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