PR4404 Prema

SZ22v10 lot code date code LED DRIVER PR4404 Low Voltage Boost Driver PR4404 for 0.5W / 1W Power LEDs The PR4404 is a step-up converter for white LEDs, operating with single battery cell supply (1.2/1.5V) at up to 150mA LED current or dual cell supply (2.4/3.0V) at up to 300mA LED current. A minimum part count allows compact and cost-efficient solutions. The converter can be switched on and off with a logic signal, which is useful e.g. for PWM control, timer circuits etc. Features Applications minimum startup voltage 1.0V LED torches supply by one or two battery cells LCD panel backlighting low number of external components home lighting battery deep discharge protection toys Typical Application Circuit Pin No Pin Name Pin Function Pin Description PR4404 Description 1 SW driver output SW Gnd(S) 1 8 2 Vout output voltage, rectified Vout Gnd(sub 3 Vcc battery supply input 2 7 ) 4 Vs LED cathode / current Vcc Gnd(A) sense resistor 3 6 5 Hold shutdown Vs Hold 4 5 6 Gnd (A) ground (analog)* 7 Gnd (sub) ground (substrate)* 8 Gnd (S) ground (power)* *Pins 6, 7, 8 must all be connected. PREMA Semiconductor GmbH 2008 Page 1/12 PRELIMINARY DATA Rev 3408LED DRIVER PR4404 Block Diagram Absolute Maximum Ratings Parameter Min Typ Max Units V (no damage) -0.3 8 V CC SW output peak current 1.5 A Operating junction temperature -20 125 C Storage Temperature Range -55 150 C Electrostatic Discharge (ESD) Protection 2 kV Electrical Characteristics Ta = 25C, unless otherwise noted. Symbol Parameter Conditions Min Typ Max Units V Supply Voltage, min. operating 0.89 V cc min. startup 1.00 1.05 V max. operating 5.0* V V SW output transistor saturation 1.0A 0.4 V sat f Switching Frequency 300 700 kHz sw V Feedback voltage threshold at Vs 200 mV FB Quiescent supply current Hold = LOW Vcc > 850mV 2.0 3.0 mA Icc Supply current Hold = open Vcc > 850mV 2.0 3.0 mA V SW output clamping voltage 14 SW Clamp JA Thermal resistance no air convection 160 K/W junction - ambient * but Vcc not higher than V (LED) F PREMA Semiconductor GmbH 2008 Page 2/12 PRELIMINARY DATA Rev 3408