White LED Driver Internal Schottky
Diode and OVP
The MIC2289C is a PWM (pulse width modulated), boost-
switching regulator that is optimized for constant-current
white LED driver applications. The MIC2289C 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
To optimize efficiency, the feedback voltage is set to only
95mV. This reduces power dissipation in the current set
resistor and allows the lowest total output voltage, hence
minimal current draw from the battery.
The MIC2289C 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
in caparison to variable frequency is much lower noise and
input ripple injected to the input power source.
The MIC2289C clamps the output voltage in case of open
LED conditions, protecting itself and the output capacitor.
The MIC2289C is available with three output OVP options
of 15V, 24V, and 34V. The different OVP options allow the
use of the smallest possible output capacitor with the
appropriate voltage rating for a given application.
The MIC2289C is available in low profile 5-pin Thin SOT-
23 and 8-pin 2mm × 2mm MLF® package options. The
MIC2289C has a junction temperature range of –40°C to
Data sheets and support documentation can be found on
Micrel’s web site at www.micrel.com.
• 2.5V to 10V input voltage
• Output voltage up to 34V
• Internal Schottky diode
• 15V, 24V, 34V output OVP options
• 1.2 MHz PWM operation
• Over 500mA switch current
• 95mV feedback voltage
• <1% line and load regulation
• <1µA shutdown current
• Overtemperature protection
• 2mm × 2mm 8-pin MLF® package
• –40°C to +125°C junction temperature range
• For higher performance specifications see the MIC2289
• White LED driver for backlighting:
– Cell phones
– GPS systems
– Digital cameras
– MP3 players
– IP phones
• LED ﬂashlights
• Constant current power supplies
EN FB 95mV
3-Series White LED Driver
3-Series LED Efficiency
700 5 10 15 20 25
MLF and MicroLeadFrame are registered 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