MIC2299 3.5A Minimum, 2MHz High Brightness LED Driver General Description Features The MIC2299 is a high power boost-switching regulator Programmable current control that is optimized for constant-current control. The MIC2299 200mV 10% feedback voltage is capable of driving up to 2 series 1A white LED for 2.5V to 10V input voltage photoflash and other applications. The feedback voltage is Output over-voltage protection (OVP) only 200mV, minimizing power dissipation in constant- current control applications, and hence extends battery Output voltage up to 30V (max) life. Fixed 2MHz Operation The MIC2299 has a brightness pin that allows for a Guaranteed 3.5A switch current over-temperature programmable torch mode as well as full flash with a 2 2 Solution size of just 0.25in (1.6cm ) single pin when driving high current LEDs. Output power range of 7W to 12W The MIC2299 implements a constant frequency 2MHz <1% line regulation PWM control scheme to make the smallest possible 1A shutdown current design. The MIC2299s 2MHz operation avoids signal interference in the AM band. Over temperature protection The 2.5V to 10V input voltage range of MIC2299 allows Externally programmable soft-start direct operation from 1- and 2-cell Li-Ion as well as 3- to 4- Under-voltage lockout (UVLO) cell NiCad/ NiMH/ Alkaline or lithium batteries. Maximum 12-pin 3mm x 3mm leadless MLF package battery life is assured with a low 1uA shutdown current. 40 C to +125 C junction temperature range The MIC2299 is available in a low profile 12-pin 3mm x 3mm MLF package. Applications Data sheets and support documentation can be found on Micrels web site at: www.micrel.com. Cell phones PDAs Digital cameras White LED flashlights Typical Application Figure 1. High Power White LED Driver 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 Micrel, Inc. MIC2299 Ordering Information Part Number OVP Frequency Junction Temp. Range Package Lead Finish MIC2299-15YML 15V 2MHz 40 to +125C 12-Pin 3x3 MLF Pb-Free Note MLF is a GREEN RoHS compliant package. Lead finish is NiPdAu. Mold compound is Halogen Free. Pin Configuration BRT 1 12 COMP SS/DIM 2 11 EN FB 3 10 VIN AGND 4 9 OVP EP PGND 5 8 SW PGND 6 7 SW 12-Pin 3mm x 3mm MLF (ML) (Top View) Pin Description Pin Number Pin Name Pin Function 1 BRT BRT (Input): Short this pin to GND to achieve 20% I (1V gives I at 100%). OUT OUT As an alternative connect a resistor to GND to control the I to >0.2I A OUT OUT 10A current source sets the voltage on the resistor. Hence a 50K resistor would yield 0.5V which would be 50% of I nominal. OUT 2 SS/DIM Soft start/dimming (input) 40k source from V . Connect a capacitor to GND FB for soft-start. Clamp the pin to a known voltage to control the internal reference voltage and hence the output current. This can also be done with a resistor to GND 3 FB Feedback (Input): Output voltage sense node. Connect the cathode of the LED to this pin. 4 AGND Analog Ground 5,6 PGND Power Ground 7,8 SW Switch Node (Input): Internal power BIPOLAR collector. 9 OVP Over-Voltage Protection (OVP): Connect to the output voltage to clamp the maximum output voltage. A resistor divider from this pin to ground could be used to raise the OVP level beyond 15V (max). 10 VIN Supply (Input): 2.5V to 10V for internal circuitry. 11 EN Enable (Input): Logic High enables regulator. Logic Low shuts down regulator. 12 COMP Compensation pin (Input): Add external R and C to GND to stabilize the converter. Pad EP Ground (Return): Backside exposed pad. M9999-101907-B October 2007 2