MIC3223 High Power Boost LED Driver with Integrated FET General Description Features The MIC3223 is a constant current boost LED driver 4.5V to 20V supply voltage capable of driving a series string of high power LEDs. The 200mV feedback voltage with an accuracy of 5% MIC3223 can be used in general lighting, bulb replacement, Step-up output voltage (boost) conversion up to 37V garden pathway lighting and other solid state illumination 1MHz switching frequency applications. 100m/3.5A internal power FET switch The MIC3223 is a peak current mode control PWM boost LEDs can be dimmed using a PWM signal regulator and the 4.5V and 20V operating input voltage User settable LED current (through external resistor) range allows multiple applications from a 5V or a 12V bus. Externally programmable soft-start The MIC3223 implements a fixed internal 1MHz switching Protection features that include: frequency to allow for a reduction in the design footprint Output over-voltage protection (OVP) size. Power consumption has been minimized through the Under-voltage lockout (UVLO) implementation of a 200mV feedback voltage that provides an accuracy of 5%. The MIC3223 can be dimmed through Over temperature protection the use of a PWM signal and features an enable pin for a Junction temperature range: -40C to +125C low power shutdown state. Available in a exposed pad 16-pin TSSOP package The MIC3223 is a very robust LED driver and offers the following protection features: over voltage protection (OVP), Applications thermal shutdown, switch current limiting and under voltage lockout (UVLO). Architectural lighting Industrial lighting The MIC3223 is offered in a low profile exposed pad 16-pin TSSOP package. Signage Landscape lighting (garden/pathway) Data sheets and support documentation can be found on Micrels web site at: www.micrel.com. Under cabinet lighting MR-16 bulbs Typical Application Micrel Inc. 2180 Fortune Drive San Jose, CA 95131 USA tel +1 (408) 944-0800 fax + 1 (408) 474-1000 Micrel, Inc. MIC3223 Ordering Information Part Number Junction Temp. Range Package Lead Finish MIC3223YTSE 40 to +125C 16-pin ePad TSSOP PB- free Pin Configuration 16-Pin ePad TSSOP (TSE) Pin Description Pin Number Pin Name Pin Function 1 EN Enable (Input): Logic high enables and logic low disables operation. 2 SS Soft Start (Input resistance of 30k). Connect a capacitor to GND for soft-start. Clamp the pin to a known voltage to control the internal reference voltage and hence the output current. 3 COMP Compensation Pin (Input): Add external R and C-to-GND to stabilize the converter. 4 FB Negative Input to Error Amp 5 OVP Connect to the centre tap of an external resistor divider, the top of which is tied to Vout and bottom-to-ground. 6 PGND Power Ground 7,8,9,10 SW Switch Node (Input): Internal NMOS switch Drain Pin 11 VIN Input Supply 12 DRVVDD For 4.5V < VIN < 6V, connect DRVVDD to VIN. DRVVDD is the input voltage supply for the converters internal power FET gate driver. For VIN > 6V, connect this pin to VDD. 13 VDD For 4.5V < VIN < 6V, this pin becomes the input voltage supply for the converters internal circuit. For VIN > 6V, this pin is an output of the internal 5.5V regulator that supplies internal circuits. User must add 10F decoupling capacitor from VDD-to-AGND. 14 DIM IN PWM input to control LED dimming. 15 DIM OUT Output driver to drive external FET for LED dimming. 16 AGND Analog Ground 17 EP Connect to Power Ground M9999-011510-A January 2010 2