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AT1313 high efficiency, constant current white-led driver 7f, no.9, park avenue ii, science-based indu strial park, hsinchu 300,taiw an, r.o.c. tel: 886-3-563-0878 fax: 886-3-563-0879 www: http://www.aimtron.com.tw 10/31/2006 rev:2.0 email: service@aimtron.com.tw 1 feature ?operating voltage:2.5v~5.5v ?high operating frequency: 1.4mhz ?high output voltage: up to 18v ?shutdown current <1 a ?18v output over-voltage protection ?digital dimming control. ?built-in cycle-by cycle current-limiting. ?built-in soft-start function. ?0.2v low reference voltage ?tiny sot-26 package application ? led module ? compact back light module ? constant current source description the AT1313 step-up converter drives white leds with a constant current to provide backlight in cell phones, pdas, and other hand-held devices. it features allowing series connection of the white leds so that the led currents are identical for uniform brightness. an enable input can be pulsed repeatedly to adjust led?s brightness. the fast 1.4 mhz current-mode pwm control allows for smaller capacitor and inductor. fault condition protection uses cycle-by-cycle current limiting to sense maximum inductor current, thermal protection and over-voltage protection. also included soft-start eliminates inrush current during start-up. the 0.2v low reference voltage minimized the power loss across the current-setting resistor. the AT1313 is available in 6-pin sot-26 packages block dia g ram lx vref + - fb on/off control logic / pwm dimming control gnd control logic en vref 0.2v n vbg 1.23v vin + - vbg ovp + - overvoltage protection current limit 1.2a ctl ctl 18v soft-start aimtron reserves the right without notice to change this circuitry and specifications.
AT1313 high efficiency, constant current white-led driver 7f, no.9, park avenue ii, science-based indu strial park, hsinchu 300,taiw an, r.o.c. tel: 886-3-563-0878 fax: 886-3-563-0879 www: http://www.aimtron.com.tw 10/31/2006 rev:2.0 email: service@aimtron.com.tw 2 pin configuration ordering information part number package marking AT1313x_ gre sot-26, green 313, date code with one bottom line : date code * for more marking information, contact our sales representative directly pin description pin n0. symbol i / o description 1 lx i step-up regulator n-mos drai n. place output diode and inductor. 2 gnd p ground 3 fb i step-up regulator feedback input. c onnect a sense resistor from fb to ground. 4 en i enable and dimming control input. led brightness and ic shutdown are controlled by the voltage on en. driving low for longer than 4ms to shutdown the ic. 5 ovp i over-voltage protection input. connect to the output. 6 vin p power supply. absolute maximum ratings [note1] parameter rated value unit vin voltage -0.3 to +6.0 v lx , ovp voltage -0.3 to +18 v en , fb to gnd -0.3 to +6.0 v switch current (i lx ) 1.2 a continuous power dissipation (sot-26 ta=+25 o c) 0.35 w operating junction temperature range -35 to 85 lead temperature (soldering 5 sec) 260 storage temperature -65 to 125 package thermal resistance ( ja ) 250 /w esd susceptibility (hbm) 2 kv esd susceptibility (mm) 200 v note1:permanent device damage may occur if absolute maximum ratings are exceeded. exposure to absolute maximum rating conditions for extended periods may affect device reliability AT1313 high efficiency, constant current white-led driver 7f, no.9, park avenue ii, science-based indu strial park, hsinchu 300,taiw an, r.o.c. tel: 886-3-563-0878 fax: 886-3-563-0879 www: http://www.aimtron.com.tw 10/31/2006 rev:2.0 email: service@aimtron.com.tw 3 recommended operation conditions values parameter symbol min. typ. max. unit power supply voltage v in 2.5 7 5.5 v operating temperature top -30 +25 +85 electrical characteristics (v in =2.5v, ta=+25 , unless otherwise noted) parameter symbol test condition min. typ. max. units operating v in range v in v in input voltage 2.5 - 5.5 v under voltage thershold uvlo v in falling, 100mv hysteresis 2.1 2.2 2.3 v switch- off input current i in1 no switching , fb>0.2v - 100 120 ua shutdown current i in3 en=0v - - 1 ua feedback reference v fb 0.190 0.2 0.210 v fb input bias current i fb v fb =0.2v - - 1 ua over-voltage threshold v ovp v out rising 16 18 20 v over-voltage hysteresis 2 v ovp leakage current i ovp en=0v - - 1 ua output voltage line regulation 2.5v< v in <6.0v - 0.1 - % switching frequency f osc 1.2 1.4 1.6 mhz maximum duty d max - 90 - % soft-start charging time t ss 0.05 0.5 ms switching current limit i lx v in =3.0v,duty cycle=80% , - 1.2 - a lx on resistance r lx v in =2.5v, i lx =800ma - 0.4 - ? lx leakage current i leakage v lx =16v, en=0v - - 1 ua en input current i en en=5v - - 1 ua v ih 2.0 - - v en input level v il - - 0.5 v en low shutdown delay 4 ms en low cycle time t cycl note(1) 0.05 5 ms en high cycle time t cych note(1) 0.05 5 ms note(1): t cycl and t cych are included rising time and falling time of pwm signal. AT1313 high efficiency, constant current white-led driver 7f, no.9, park avenue ii, science-based indu strial park, hsinchu 300,taiw an, r.o.c. tel: 886-3-563-0878 fax: 886-3-563-0879 www: http://www.aimtron.com.tw 10/31/2006 rev:2.0 email: service@aimtron.com.tw 4 typical characteristics efficiency vs. vin (4 led) l:sr0302 d:rb501-40 vin (v) efficiency ( %) * p n " - v ) * p n " - v ) * p n " - v ) conversion efficiency l:sr0302 d:rb501-40 led current(ma) efficiency (%) - & |