?2004 fairchild semiconductor corporation www.fairchildsemi.com rev. 1.0.1 features ? wide dimming range analog dimming ( 2.5 : 1 ) burst dimming ( >100 : 1 ) ? high efficiency single stage power conversion ? wide input voltage range 7.4v to 20v ? back light lamp ballast and soft dimming ? few external components ? precision voltage reference trimmed to 2% ? zvs full-bridge topology ? soft start ? pwm control at fixed frequency ? analog, burst dimming function ? open lamp protection ? open lamp regulation ? short lamp protection ? thermal protection ? 20 pin ssop description the FAN7315 provides all the control functions for a series parallel resonant converter and also contains a pulse width modulation (pwm) controller to develop a supply voltage. typical operating frequency range is between 30khz and 250khz depending on the ccfl and the transformer's characteristics. 20-ssop FAN7315 lcd back light inverter drive ic
FAN7315 2 internal block diagram bdim s_s ea_out oscillator rt error amp. ea_in 5.2ua ct adim outb outa outc outd vin 2.5vref ena uvlo 7.4v uvlo ref bct + - 1.4v q q set clr s r uvlo 300mv olp - + pgnd voltage reference & internal bias vin output driver output control logic agnd output driver s olr s burst s burst 240ua 240ua olr - + 2v s olr scp - + 2v thermal protection - + - + +
FAN7315 3 pin assignments pin definitions no name function description no name function description 1 olp open lamp protection 11 bct burst dimming timing capacitor 2 olr open lamp regulation 12 rt timing resistor 3 ena enable input 13 ct timing capacitor 4 s/s soft start 14 outd nmosfet drive output d 5 agnd analog ground 15 outc pmosfet drive output c 6 v25 2.5v reference voltage 16 pgnd power ground 7 adim analog dimming input 17 vin supply voltage 8 bdim burst dimming input 18 outa pmosfet drive output a 9 ea_in error amplifier input 19 outb nmosfet drive output b 10 ea_out error amplifier output 20 scp short circuit protection FAN7315 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 olp olr ena s_s outc ref adim bdim ea_in ea_out scp outb outa vin pgnd outd rt bct agnd ct
FAN7315 4 absolute maximum ratings vcc=12v, for typical values ta=25 c, for min/max values ta is the operating ambient temperature range with -40 c ta 85 c and 7.4v vcc 20v, unless otherwise specified. note: 1. thermal resistance test board size: 76.2mm * 114.3m m * 1.6mm(1s0p) jedec standard: jesd51-3, jesd51-7 2. assume no ambient airflow characteristics symbol value unit supply voltage v cc 7.4 ~ 20 v operating temperature range topr -40 ~ 85 c storage temperature range tstg -65 ~ 150 c thermal resistance junction-air (note1,2) r ja 112 c/w power dissipation pd 1.1 w
FAN7315 5 electrical characteristics vcc=12v, for typical values ta=25 c, for min/max values ta is the operating ambient temperature range with -40 c ta 85 c and 7.4v vcc 20v, unless otherwise specified. characteristics symbol test condition min. typ. max. unit reference section load regulation ? v25load 0 i25 3ma - 2 25 mv line regulation ? v25line 7.4v v cc 20v - 2 25 mv 2.5v regulation voltage v25 - 2.44 2.49 2.54 v oscillator section(main) oscillation frequency fosc ta=25 c, ct = 330pf, rt = 45k 93 100 107 khz ct = 330pf, rt = 45k 89 100 111 khz ct high voltage vcth - - 1.95 - v ct low voltage vbctl - - 0.5 - v oscillator section(burst) oscillation frequency foscb ctb = 6.8nf, rt=45k 150 191 232 hz bct high voltage vbcth - - 2 - v bct low voltage vbctl - - 0.5 - v error amp section error amp transconductance(note1) gm va = 1~2.5v 100 360 600 umho output sink current lsin ea_out = 1v 44 73 100 ua output source current lsur ea_out = 1v 33 50 67 ua open lamp regulation current iolr olr=2.5v 160 240 320 ua ea_out high volgate vea_outh 2.2 2.5 2.8 v soft start section soft start current i ss s_s=0v 3.5 5.2 6.9 ua soft start clamping voltage vssh - 2.2 2.55 2.9 v protection section open lamp protection voltage volp - 245 300 425 mv open lamp regulation voltage volr - 1.8 2 2.2 v short circuit protection voltage vscp - 1.75 2 2.25 v thermal shutdown on temp.(note1) tsdon - 130 150 170 c tsd hysterisis(note1) tsdhy - - 30 - c under voltage lock out section start threshold voltage on vthon - 5.2 6.3 7.4 v uvlo hysteresis vhys - 100 300 500 mv start up current ist v cc = vth-0.2v 48 85 122 ua operating supply current iop v cc = 12v - - 2 ma stand-by current isb v cc = 12v, ena=0v 55 80 105 ua
FAN7315 6 electrical characteristics (continued) vcc=12v, for typical values ta=25 c, for min/max values ta is the operating ambient temperature range with -40 c ta 85 c and 7.4v vcc 20v, unless otherwise specified. note: 1. these parameters, although guaranteed, are not 100% tested in production. characteristics symbol test condition min. typ. max. unit on/off section off state input voltage voff - - - 0.7 v on state input voltage von - 2.1 - - v output section pmos gate high voltage vpdhv v cc =12v - vcc - v pmos gate low voltage vpdlv v cc =12v vcc- 7.25 vcc-6.5 vcc- 5.55 nmos gate high voltage vndhv v cc = 12v 5.55 6.5 7.25 v nmos gate low voltage vndlv v cc =12v 0.2 pmos gate voltage with uvlo activated vpuv v cc = vth-0.5v vcc-0.2 - - v nmos gate voltage with uvlo activated vnuv v cc = vth-0.5v - - 0.2 rising time(note1) tr v cc = 12v, cload=1700pf - 100 300 ns falling time(note1) tf v cc = 12v, cload=1700pf - 100 300 ns max./min overlap min. overlap between diagonal switches(note1) fosc=100khz - 0 - % max. overlap betwwen diagonal switches(note1) fosc=100khz - 100 - % delay time pdr_a/ndr_b(note1) fosc=100khz, rt=45k - 325 - ns pdr_c/ndr_d(note1) fosc=100khz, rt=45k - 325 - ns
FAN7315 7 mechanical dimensions package dimensions in millimeters 20-ssop
FAN7315 10/6/04 0.0m 001 stock#dsxxxxxxxx ? 2002 fairchild semiconductor corporation life support policy fairchild?s products are not authorized for use as critical components in life support devices or systems without the express written approval of the president of fairchild semiconductor corporation. as used herein: 1. life support devices or systems are devices or systems which, (a) are intended for surgical implant into the body, or (b) support or sustain li fe, and (c) whose failure to perform when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury of the user. 2. a critical component in any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness. www.fairchildsemi.com disclaimer fairchild semiconductor reserves the right to make changes without further notice to any products herein to improve reliability, function or design. fairchild does not assume any liability arising out of the application or use of any product or circuit described herein; neither does it convey any license under its patent rights, nor the rights of others. ordering information product number package operating temperature FAN7315g 20-ssop -40 c ~ 85 c
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