MIC2289
White LED Driver Internal Schottky Diode and OVP
Features
2.5V to 10V Input Voltage Range
Output Voltage up to 34V
Internal Schottky Diode
15V, 24V, 34V Output OVP Options
1.2 MHz PWM Operation
Over 500 mA Switch Current
95 mV Feedback Voltage
<1% Line and Load Regulation
<1 μA Shutdown Current
Overtemperature Protection
UVLO
6-Pin Thin SOT-23 and 2 mm x 2 mm DFN-8
Package Options
• –40°C to +125°C Junction Temperature Range
•
•
•
•
•
•
•
•
•
•
•
•
General Description
The MIC2289 is a PWM (pulse width modulated),
boost-switching regulator that is optimized for constant
current white LED driver applications. The MIC2289
features an internal Schottky diode and three levels of
output overvoltage protection providing a small size
and efficient DC/DC solution that requires only four
external components.
To optimize efficiency, the feedback voltage is set to
only 95 mV. This reduces power dissipation in the
current setting resistor and allows the lowest total
output voltage, hence minimizes current draw from the
battery.
The MIC2289 implements a constant frequency
1.2 MHz PWM control scheme. The high frequency,
PWM operation saves board space by reducing
external component sizes. The added benefit of the
constant frequency PWM scheme in comparison to
variable frequency is much lower noise and input ripple
injected to the input power source.
The MIC2289 clamps the output voltage in case of
open LED conditions, protecting itself and the output
capacitor. The MIC2289 is available with three output
OVP options of 15V, 24V, and 34V. The different OVP
options allows the use of the smallest possible output
capacitor with the appropriate voltage rating for a given
application.
The MIC2289 is available in low profile 6-pin Thin
SOT-23 and 8-pin 2 mm × 2 mm DFN package options.
The MIC2289 has a junction temperature range of
–40°C to +125°C.
Applications
• White LED Driver for Backlighting:
- Cell Phones
- PDAs
- GPS Systems
- Digital Cameras
- MP3 Players
- IP Phones
• LED Flashlights
• Constant Current Power Supplies
Package Types
MIC2289
DFN-8 (ML)
(Top View)
MIC2289
Thin SOT23-6 (D6)
(Top View)
OUT
VIN
EN
AGND
1
2
3
4
8
7
6
PGND
SW
FB
NC
FB GND SW
3
2
1
EP
5
4
5
6
EN VIN OUT
2019 Microchip Technology Inc.
DS20006207A-page 1
MIC2289
Typical Application Circuit
10μH
MIC2289-15YML
1-Cell
Li Ion
VIN
1μF
OUT
EN
GND
FB
95mV
SW
0.22μF/16V
Functional Block Diagram
VIN
FB
EN
OUT
OVP
SW
g
m
V
REF
95mV
S
PWM
Generator
1.2MHz
Oscillator
Ramp
Generator
GND
DS20006207A-page 2
2019 Microchip Technology Inc.
MIC2289
1.0
ELECTRICAL CHARACTERISTICS
Absolute Maximum Ratings †
Supply Voltage (V
IN
) ................................................................................................................................................ +12V
Switch Voltage (V
SW
) ................................................................................................................................. –0.3V to +34V
Enable Pin Voltage (V
EN
) .............................................................................................................................. –0.3V to V
IN
FB Voltage (V
FB
) ..................................................................................................................................................... +6.0V
Switch Current (I
SW
)......................................................................................................................................................2A
Schottky Reverse Voltage (V
DR
) .................................................................................................................................34V
Ambient Storage Temperature Range (T
S
) ............................................................................................–65°C to +150°C
ESD Rating (Note
1)
..................................................................................................................................................2 kV
Operating Ratings ††
Supply Voltage (V
IN
) .................................................................................................................................. +2.5V to +10V
Output Voltage (V
OUT
) ................................................................................................................................... V
IN
to V
OVP
Junction Temperature Range (T
J
) ..........................................................................................................–40°C to +125°C
Package Thermal Resistance
2 mm x 2 mm DFN (
JA
) ...................................................................................................................................... 93°C/W
Thin SOT23-6 (
JA
) ............................................................................................................................................ 177°C/W
† Notice:
Stresses above those listed under “Absolute Maximum Ratings” may cause permanent damage to the device.
This is a stress rating only and functional operation of the device at those or any other conditions above those indicated
in the operational sections of this specification is not intended. Exposure to maximum rating conditions for extended
periods may affect device reliability.
†† Notice:
The device is not guaranteed to function outside its operating ratings.
Note 1:
Devices are ESD sensitive. Handling precautions are recommended. Human body model, 1.5 kΩ in series
with 100 pF.
2019 Microchip Technology Inc.
DS20006207A-page 3
MIC2289
ELECTRICAL CHARACTERISTICS
Electrical Characteristics:
T
A
= +25°C, V
IN
= V
EN
= 3.6V, V
OUT
= 10V, I
OUT
= 20 mA, unless otherwise noted.
Bold
values indicate –40°C ≤ T
J
≤ ±125°C.
Note 1
Parameter
Supply Voltage Range
Undervoltage Lockout
Quiescent Current
Shutdown Current
Feedback Voltage
Feedback Input Current
Line Regulation
Load Regulation
Maximum Duty Cycle
Switch Current Limit
Switch Saturation Voltage
Switch Leakage Current
Enable Logic Level High
Enable Logic Level Low
Enable Pin Current
Oscillator Frequency
Schottky Forward Drop
Schottky Leakage Current
Output Overvoltage
Protection
Overtemperature
Shutdown Threshold
Overtemperature
Shutdown Hysteresis
Note 1:
2:
3:
Symbol
V
IN
V
UVLO
I
VIN
I
SD
V
FB
I
FB
—
—
D
MAX
I
SW(LIM)
V
SW(SAT)
I
SW(LK)
V
EN_H
V
EN_L
I
EN
f
SW
V
D
I
RD
V
OVP
Min.
2.5
1.8
—
—
90
—
—
—
85
—
—
—
1.5
—
—
1.05
—
—
13
21
30
T
SD
T
SD_HYS
—
—
Typ.
—
2.1
2.5
0.1
95
–450
0.5
0.5
90
750
450
0.01
—
—
20
1.2
0.8
—
14
22.5
32
150
10
Max.
10
2.4
5
1
100
—
1
—
—
—
—
5
—
0.4
40
1.35
1
4
16
24
34
—
°C
—
Hysteresis
V
μA
MHz
V
μA
Units
V
V
mA
μA
mV
nA
%
%
%
mA
mV
μA
V
—
—
V
FB
> 200 mV, not switching
V
EN
= 0V,
Note 2
±5%
V
FB
= 95 mV
3V ≤ V
IN
≤ 5V,
Note 3
5 mA ≤ I
OUT
≤ 20 mA,
Note 3
—
—
I
SW
= 0.5A
V
EN
= 0V, V
SW
= 10V
Turn on
Turn off
V
EN
= 10V
—
I
D
= 150 mA
V
R
= 30V
MIC2289-15
MIC2289-24
MIC2289-34
—
Conditions
Specification for packaged product only.
I
SD
= Current drawn by the device into the VIN pin during shutdown.
Guaranteed by design.
DS20006207A-page 4
2019 Microchip Technology Inc.
MIC2289
TEMPERATURE SPECIFICATIONS
Parameters
Temperature Ranges
Junction Operating Temperature
Maximum Junction Temperature
Storage Temperature Range
Package Thermal Resistances
Thermal Resistance, 2x2 DFN 8-Lead
Thermal Resistance, TSOT23-6
Note 1:
JA
JA
—
—
93
177
—
—
°C/W
°C/W
—
—
T
J
T
J(ABS)
T
S
–40
—
–65
—
—
—
+125
+150
+150
°C
°C
°C
—
—
—
Symbol
Min.
Typ.
Max.
Units
Conditions
The maximum allowable power dissipation is a function of ambient temperature, the maximum allowable
junction temperature and the thermal resistance from junction to air (i.e., T
A
, T
J
,
JA
). Exceeding the
maximum allowable power dissipation will cause the device operating junction temperature to exceed the
maximum +125°C rating. Sustained junction temperatures above +125°C can impact the device reliability.
2019 Microchip Technology Inc.
DS20006207A-page 5
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