LED Driver. MIC2287 Datasheet

MIC2287 Driver. Datasheet pdf. Equivalent

MIC2287 Datasheet
Recommendation MIC2287 Datasheet
Part MIC2287
Description 1.2MHz PWM White LED Driver
Feature MIC2287; MIC2287 MIC2287 Micrel, Inc. 1.2MHz PWM White LED Driver with OVP in 2mm × 2mm MLF™ and Thin SOT-.
Manufacture Micrel Semiconductor
Datasheet
Download MIC2287 Datasheet




Micrel Semiconductor MIC2287
MIC2287
MIC2287
Micrel, Inc.
1.2MHz PWM White LED Driver with OVP in
2mm × 2mm MLF™ and Thin SOT-23
General Description
The MIC2287 is a 1.2MHz pulse width modulated (PWM),
boost-switching regulator that is optimized for constant-
current, white LED driver applications. With a maximum
output voltage of 34V and a switch current of over 500mA,
the MIC2287 easily drives a string of up to 8 white LEDs in
series, ensuring uniform brightness and eliminating several
ballast resistors.
The MIC2287 implements a constant frequency, 1.2MHz
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
as opposed to variable frequency topologies is much lower
noise and input ripple injected back to the battery source.
To optimize efficiency, the feedback voltage is set to only
95mV. This reduces the power dissipation in the current set
resistor and allows the lowest total output voltage, hence
minimal current draw from the battery.
The MIC2287 is available with 3 levels of overvoltage protec-
tion, 15V, 24V, and 34V. This allows designers to choose the
smallest possible external components with the appropriate
voltage ratings for their applications.
The MIC2287 is available in low profile Thin SOT-23 5-lead and
an 8-lead 2mm × 2mm MLF™ package options. The MIC2287
has a junction temperature range of –40°C to +125°C.
All support documentation can be found on Micrel’s web site
at www.micrel.com.
Features
• 2.5V to 10V input voltage
• Output voltage up to 34V
• Over 500mA switch current
• 1.2 MHz PWM operation
• 95mV feedback voltage
• Output Overvoltage Protection (OVP)
• Options for 15V, 24V, and 34V OVP
• <1% line and load regulation
• <1µA shutdown current
• Over-temperature protection
• UVLO
• Low profile Thin SOT-23-5 package option
• 8-lead 2mm × 2mm MLF™ package option
• –40°C to +125°C junction temperature range
Applications
• White LED driver for backlighting:
- Cell phones
- PDAs
- GPS systems
- Digital cameras
- MP3 players
- IP phones
• Photo flash LED driver
• LED flashlights
• Constant current power supplies
Typical Application
10µH
CMDSH-3
1-Cell
Li Ion
MIC2287BD5
5 VIN
SW 1
1µF
4 EN
FB 3
95mV
GND
2
6.3Ω
0.22µF
1-Cell
Li Ion
10µH
CMDSH-3
MIC2287-34BML
VIN SW
1µF EN OVP
FB
GND
95mV
6.3Ω
0.22µF
3-Series White LED Driver in Thin SOT-23
6-Series White LED Driver
with Output OVP in 2mm × 2mm MLF™-8
MLF and MicroLeadFrame are trademarks of Amkor Technology, 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
July 2005
1 M9999-070105



Micrel Semiconductor MIC2287
MIC2287
Ordering Information
Part Number
Marking Overvoltage
Code
Protection
MIC2287BD5
SGAA
N/A
MIC2287YD5
SGAA
N/A
MIC2287-15BML
SLA
15V
MIC2287-15YML
SLA
15V
MIC2287-24BML
SLB
24V
MIC2287-24YML
SLB
24V
MIC2287-34BML
SLC
34V
MIC2287-34YML
SLC
34V
Junction
Temp. Range
Package
–40°C to 125°C Thin SOT-23-5
–40°C to 125°C Thin SOT-23-5
–40°C to 125°C 2mm x 2mm MLF™
–40°C to 125°C 2mm x 2mm MLF™
–40°C to 125°C 2mm x 2mm MLF™
–40°C to 125°C 2mm x 2mm MLF™
–40°C to 125°C 2mm x 2mm MLF™
–40°C to 125°C 2mm x 2mm MLF™
Lead Finish
Standard
Lead Free
Standard
Lead Free
Standard
Lead Free
Standard
Lead Free
Micrel, Inc.
Pin Configuration
FB GND SW
321
45
EN VIN
TSOT-23-5 (BD5)
OUT 1
VIN 2
EN 3
GND 4
8 GND
7 SW
6 FB
EP 5 NC
8-Pin MLF™ (BML)
(Top View)
Fused Lead Frame
Pin Description
Pin Number Pin Number
TSOT-23-5 2mm ×2mm MLF™
17
2
36
Pin Name
SW
GND
FB
43
EN
52
—1
—4
—8
—5
— EP
VIN
OVP
AGND
PGND
NC
GND
Pin Function
Switch node (Input): Internal power BIPOLAR collector.
Ground (Return): Ground.
Feedback (Input): Output voltage sense node. Connect the cathode of the
LED to this pin. A resistor from this pin to ground sets the LED current.
Enable (Input): Logic high enables regulator. Logic low shuts down regula-
tor.
Supply (Input): 2.5V to 10V for internal circuitry.
Overvoltage protection (Input): Connect to the output.
Analog ground.
Power ground.
No connect (no internal connection to die).
Ground (Return): Exposed backside pad.
M9999-070105
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July 2005



Micrel Semiconductor MIC2287
MIC2287
Absolute Maximum Ratings(1)
Supply Voltage (VIN) ..................................................... 12V
Switch Voltage (VSW) ......................................–0.3V to 34V
Enable Pin Voltage (VEN) ................................... –0.3 to VIN
FB Voltage (VFB) ............................................................. 6V
Switch Current (ISW) ........................................................ 2A
Ambient Storage Temperature (TS) .......... –65°C to +150°C
ESD Rating(3) ............................................................... 2kV
Micrel, Inc.
Operating Ratings(2)
Supply Voltage (VIN)..........................................2.5V to 10V
Junction Temperature Range (TJ) ............ –40°C to +125°C
Package Thermal Impedance
2mm × 2mmMLF™ (θJA) ..................................... 93°C/W
Thin SOT-23-5 (θJA) ......................................... 256°C/W
Electrical Characteristics(4)
TA = 25°C, VIN = VEN = 3.6V, VOUT = 10V, IOUT = 10mA, unless otherwise noted. Bold values indicate –40°C ≤ TJ ≤125°C.
Symbol
Parameter
Condition
Min Typ Max
VIN
VUVLO
IVIN
ISD
VFB
IFB
DMAX
ISW
VSW
ISW
VEN
Supply Voltage Range
Under Voltage Lockout
Quiescent Current
Shutdown Current
Feedback Voltage
Feedback Input Current
Line Regulation(6)
Load Regulation(6)
Maximum Duty Cycle
Switch Current Limit
Switch Saturation Voltage
Switch Leakage Current
Enable Threshold
VFB > 200mV, (not switching)
VEN = 0V(5)
(±5%)
VFB = 95mV
3V ≤ VIN ≤ 5V
5mA ≤ IOUT ≤ 20mA
ISW = 0.5A
VEN = 0V, VSW = 10V
TURN ON
TURN OFF
2.5 10
1.8 2.1 2.4
2.5 5
0.1 1
90 95 100
–450
0.5 1
0.5 2
85 90
750
450
0.01 5
1.5
0.4
IEN
fSW
VOVP
Enable Pin Current
Oscillator Frequency
Overvoltage Protection
VEN = 10V
MIC2287BML- 15 only
MIC2287BML- 24 only
MIC2287BML- 34 only
20 40
1.05 1.2 1.35
13 14 16
21 22.5 24
30 32 34
TJ Overtemperature
Threshold Shutdown
Hysteresis
150
10
Units
V
V
mA
µA
mV
nA
%
%
%
mA
mV
µA
V
V
µA
MHz
V
V
V
°C
°C
Notes:
1. Absolute maximum ratings indicate limits beyond which damage to the component may occur. Electrical specifications do not apply when operating
the device outside of its operating ratings. The maximum allowable power dissipation is a function of the maximum junction temperature, TJ(max),
the junction-to-ambient thermal resistance, θJA, and the ambient temperature, TA. The maximum allowable power dissipation will result in excessive
die temperature, and the regulator will go into thermal shutdown.
2. This device is not guaranteed to operate beyond its specified operating ratings.
3. Devices are inherently ESD sensitive. Handling precautions required. Human body model.
4. Specification for packaged product only.
5. ISD = IVIN.
6. Guaranteed by design.
July 2005
3 M9999-070105







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