MIC2287C_11 Datasheet, PDF (1/9 Pages) Micrel Semiconductor – 1.2MHz PWM White LED Driver with OVP in 2mm × 2mm MLF and Thin SOT-23

MIC2287C
Micrel
MIC2287C
1.2MHz PWM White LED Driver with OVP in
2mm × 2mm MLF™ and Thin SOT-23
General Description
The MIC2287C is a 1.2MHz pulse width modulated (PWM),
boost-switching regulator that is optimized for constant-cur-
rent, white LED driver applications. With a maximum output
voltage of 37V and a switch current of over 500mA, the
MIC2287C easily drives a string of up to 6 white LEDs in
series, ensuring uniform brightness and eliminating several
ballast resistors.
The MIC2287C 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 MIC2287C 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 MIC2287C is available in low profile Thin SOT-23 5-
lead and an 8-lead 2mm × 2mm MLF™ package options.
The MIC2287C has a junction temperature range of –40°C
to +105°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
• Over-temperature protection
• UVLO
• Low profile Thin SOT-23-5 package option
• 8-lead 2mm × 2mm MLF™ package option
• –40°C to +105°C junction temperature range
• For higher performance specifications see the MIC2287
Applications
• White LED driver for backlighting:
- Cell phones
- PDAs
- GPS systems
- Digital cameras
- MP3 players
- IP phones
• LED flashlights
Typical Application
10�H
CMDSH-3
1-Cell
Li Ion
MIC2287CBD5
5
VIN
1
SW
1�F
4 _EN
FB ³
95mV
GND
2
6.3�
0.22�F
1-Cell
Li Ion
10�H
CMDSH-3
MIC2287C-34BML
VIN SW
1�F
EN OVP
FB
GND
95mV
6.3�
0.22�F
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 [phone] • fax + 1 [phone] • http://www.micrel.com
February 2006
1
M0510-020906