TK11851 DCDC Converter, 1ch, Step-up, Inductive DCDC1ch Feature Very high speed adjustable OSC - 800kHz max - 800kHz max Low loss detector - Vref=0.515V - low reference voltage: Vref=0.515V Operates with TOKO d31fu, D31FB miniature coil (current limited by inductor current sensor) Internal switching transistor 20V - 400mApeakMAX - 400mApeakMAX Open-circuit protection (OVP) (OVP) Active high on / off control En(ON/OFF, 1A) Available intensity control PWM(En) using En pin with PWM signal Low component count Operating Voltage Range VOP=2.3 to 10V VOP=2.3~10V TOP=-30~+85C Operating Temp. Range TOP=-30 to +85C Power Dissipation PD=400mW PD=400mW Characteristics Part Name TK11851 Number of Current Stabilizer - fOSC Number of LED in serial connection 2 to 4 LED 800kHz ILED Max 15mA Ordering Guide, Marking Part Name TK11851 Ordering Name Marking TK11851LTL-GH Description Order Size TK11851: Part Name 1,300 L: SOT23L-8 Package pcs. TL: Tape&Reel, Left /Reel -GH: PB-Free&Halogen Free 1851 Block Diagram, Standard Application TK11851L TK11851 Vin 1 Band Gap Reference VIs Is Comp 8 0.1V Rsc Is 1 En 0.3 22H Cx OSC 2 L CIN 1F 7 0.86V Cx 0.3V D CLK 3 S 4 Page 126 Gnd R En IS CX EXT VOVP VLED 6 Q Vovp 3 4 CLK Ext 2 VIN GND VFB 8 on/off 7 6 5 CX 68pF RLED 33 ILED Error 0.515V Vref Comp Vfb COUT 2.2F 5 2010 AUTUMN