parameter symbol irf7805 irf7805a units drain-source voltage v ds 30 v gate-source voltage v gs 12 continuous drain or source 25c i d 13 13 a current (v gs 4.5v) 70c 10 10 pulsed drain current i dm 100 100 power dissipation 25c p d 2.5 w 70c 1.6 junction & storage temperature range t j , t stg ?55 to 150 c continuous source current (body diode) i s 2.5 2.5 a pulsed source current i sm 106 106 ? n channel application specific mosfets ? ideal for mobile dc-dc converters ? low conduction losses ? low switching losses ? lead-free description these new devices employ advanced hexfet power mosfet technology to achieve an unprecedented balance of on-resistance and gate charge. the reduced conduction and switching losses make them ideal for high efficiency dc-dc converters that power the latest generation of mobile microprocessors. the irf7805/irf7805a offers maximum efficiency for mobile cpu core dc-dc converters. hexfet ? chip-set for dc-dc converters irf7805 irf7805a vds 30v 30v rds(on) 11m ? 11m ? qg 31nc 31nc qsw 11.5nc qoss 36nc 36nc absolute maximum ratings parameter max. units maximum junction-to-ambient r ja 50 c/w thermal resistance top view 8 1 2 3 4 5 6 7 d d d d g s a s s device features irf7805/IRF7805APBF www.irf.com 1 11/9/04 so-8 pd ? 95937
www.irf.com 2 irf7805/IRF7805APBF parameter min typ max min typ max units conditions diode forward v sd 1.2 1.2 v i s = 7a , v gs = 0v voltage* reverse recovery q rr 88 88 nc di/dt = 700a/s charge v ds = 16v, v gs = 0v, i s = 7a reverse recovery q rr(s) 55 55 charge (with parallel schotkky) parameter min typ max min typ max units conditions drain-to-source v (br)dss 30 ? ? 30 ? ? v v gs = 0v, i d = 250a breakdown voltage* static drain-source r ds (on) 9.2 11 9.2 11 m ? v gs = 4.5v, i d = 7a on resistance* gate threshold voltage* v gs (th) 1.0 1.0 v v ds = v gs ,i d = 250a drain-source leakage i dss 30 30 a v ds = 24v, v gs = 0 150 150 v ds = 24v, v gs = 0, tj = 100c gate-source leakage i gss 100 100 na v gs = 12v current* total gate charge* q g 22 31 22 31 v gs = 5v, i d = 7a pre-vth q gs1 3.7 3.7 v ds = 16v, i d = 7a gate-source charge post-vth q gs2 1.4 1.4 nc gate-source charge gate to drain charge q gd 6.8 6.8 switch charge* q sw 8.2 11.5 8.2 (q gs2 + q gd ) output charge* q oss 30 36 30 36 v ds = 16v, v gs = 0 gate resistance r g 1.7 1.7 ? turn-on delay time t d (on) 16 16 v dd = 16v rise time t r 20 20 ns i d = 7a turn-off delay time t d (off) 38 38 r g = 2 ? fall time t f 16 16 v gs = 4.5v resistive load electrical characteristics source-drain rating & characteristics notes: repetitive rating; pulse width limited by max. junction temperature. pulse width 300 s; duty cycle 2%. when mounted on 1 inch square copper board, t < 10 sec. measured at v ds < 100mv. this approximates actual operation of a synchronous rectifier. typ = measured - q oss * devices are 100% tested to these parameters. irf7805 irf7805a current* di/dt = 700a/s (with 10bq040) v ds = 16v, v gs = 0v, i s = 7a
www.irf.com 3 irf7805/IRF7805APBF control fet special attention has been given to the power losses in the switching elements of the circuit - q1 and q2. power losses in the high side switch q1, also called the control fet, are impacted by the r ds(on) of the mosfet, but these conduction losses are only about one half of the total losses. power losses in the control switch q1 are given by; p loss = p conduction + p switching + p drive + p output this can be expanded and approximated by; p loss = i rms 2 r ds(on ) () + i q gd i g v in f ? ? ? ? ? ? + i q gs2 i g v in f ? ? ? ? ? ? + q g v g f () + q oss 2 v in f ? ? ? ? this simplified loss equation includes the terms q gs2 and q oss which are new to power mosfet data sheets. q gs2 is a sub element of traditional gate-source charge that is included in all mosfet data sheets. the impor- tance of splitting this gate-source charge into two sub elements, q gs1 and q gs2 , can be seen from fig 1. q gs2 indicates the charge that must be supplied by the gate driver between the time that the threshold volt- age has been reached (t1) and the time the drain cur- rent rises to i dmax (t2) at which time the drain voltage begins to change. minimizing q gs2 is a critical factor in reducing switching losses in q1. q oss is the charge that must be supplied to the output capacitance of the mosfet during every switching cycle. figure 2 shows how q oss is formed by the paral- lel combination of the voltage dependant (non-linear) capacitance?s c ds and c dg when multiplied by the power supply input buss voltage. figure 1: typical mosfet switching waveform synchronous fet the power loss equation for q2 is approximated by; p loss = p conduction + p drive + p output * p loss = i rms 2 r ds(on) () + q g v g f () + q oss 2 v in f ? ? ? ? ? + q rr v in f ( ) *dissipated primarily in q1. power mosfet selection for dc/dc converters 4 1 2 drain current gate voltage drain voltage t3 t2 t1 v gth q gs1 q gs2 q gd t0
www.irf.com 4 irf7805/IRF7805APBF figure 2: q oss characteristic for the synchronous mosfet q2, r ds(on) is an im- portant characteristic; however, once again the impor- tance of gate charge must not be overlooked since it impacts three critical areas. under light load the mosfet must still be turned on and off by the con- trol ic so the gate drive losses become much more significant. secondly, the output charge q oss and re- verse recovery charge q rr both generate losses that are transfered to q1 and increase the dissipation in that device. thirdly, gate charge will impact the mosfets? susceptibility to cdv/dt turn on. the drain of q2 is connected to the switching node of the converter and therefore sees transitions be- tween ground and v in . as q1 turns on and off there is a rate of change of drain voltage dv/dt which is ca- pacitively coupled to the gate of q2 and can induce a voltage spike on the gate that is sufficient to turn the mosfet on, resulting in shoot-through current . the ratio of q gd /q gs1 must be minimized to reduce the potential for cdv/dt turn on. spice model for irf7805 can be downloaded in ma- chine readable format at www.irf.com.
www.irf.com 5 irf7805/IRF7805APBF figure 7. typical rds(on) vs. gate-to-source voltage figure 5. typical gate charge vs. gate-to-source voltage figure 3. normalized on-resistance vs. temperature figure 8. typical rds(on) vs. gate-to-source voltage figure 6. typical gate charge vs. gate-to-source voltage figure 4. normalized on-resistance vs. temperature irf7805 irf7805a typical characteristics
www.irf.com 6 irf7805/IRF7805APBF 0.1 1 10 0.4 0.5 0.6 0.7 0.8 0.9 v ,source-to-drain voltage (v) i , reverse drain current (a) sd sd v = 0 v gs t = 25 c j t = 150 c j irf7805 irf7805a 0.1 1 10 100 0.001 0.01 0.1 1 10 100 1000 notes: 1. duty factor d = t / t 2. peak t = p x z + t 1 2 j dm thja a p t t dm 1 2 t , rectangular pulse duration (sec) thermal response (z ) 1 thja 0.01 0.02 0.05 0.10 0.20 d = 0.50 single pulse (thermal response) figure 9. typical source-drain diode forward voltage figure 10. typical source-drain diode forward voltage figure 11. maximum effective transient thermal impedance, junction-to-ambient 0.1 1 10 0.4 0.5 0.6 0.7 0.8 0.9 v ,source-to-drain voltage (v) i , reverse drain current (a) sd sd v = 0 v gs t = 25 c j t = 150 c j
www.irf.com 7 irf7805/IRF7805APBF so-8 package outline dimensions are shown in milimeters (inches) e1 d e y b a a1 h k l .189 .1497 0 .013 .050 basic .0532 .0040 .2284 .0099 .016 .1968 .1574 8 .020 .0688 .0098 .2440 .0196 .050 4.80 3.80 0.33 1.35 0.10 5.80 0.25 0.40 0 1.27 b as ic 5.00 4.00 0.51 1.75 0.25 6.20 0.50 1.27 mi n max millimeters inches mi n max dim 8 e c .0075 .0098 0.19 0.25 .025 basic 0.635 bas ic 87 5 65 d b e a e 6x h 0.25 [.010] a 6 7 k x 45 8x l 8x c y 0.25 [.010] c a b e1 a a1 8x b c 0.10 [.004] 4 3 12 f oot p r i nt 8x 0.72 [.028] 6.46 [.255] 3x 1.27 [.050] 4. ou t l i ne conf or ms t o j e de c ou t l i ne ms -012aa. not e s : 1. dimens ioning & t olerancing pe r as me y14.5m-1994. 2. cont roll ing dime ns ion: mil lime te r 3. di me ns i ons ar e s h own i n mi l l i me t e r s [i nch e s ] . 5 dimens ion doe s not incl ude mol d prot rus ions . 6 dimens ion doe s not incl ude mol d prot rus ions . mold prot rus ions not t o e xce e d 0.25 [.010]. 7 dimens ion is t he le ngt h of l e ad f or s ol dering t o a s ubs t rat e. mold prot rus ions not t o e xce e d 0.15 [.006]. 8x 1.78 [.070] so-8 part marking information (lead-free) dat e code (yww) xxxx international rectifier logo f7101 y = last digit of the year part number lot code ww = week example : t his is an irf7101 (mos fe t ) p = designates lead-free product (opt ional) a = as s e mb l y s i t e code
www.irf.com 8 irf7805/IRF7805APBF 330.00 (12.992) max. 14.40 ( .566 ) 12.40 ( .488 ) notes : 1. controlling dimension : millimeter. 2. outline conforms to eia-481 & eia-541. feed direction terminal number 1 12.3 ( .484 ) 11.7 ( .461 ) 8.1 ( .318 ) 7.9 ( .312 ) notes: 1. controlling dimension : millimeter. 2. all dimensions are shown in millimeters(inches). 3. outline conforms to eia-481 & eia-541. so-8 tape and reel dimensions are shown in milimeters (inches) data and specifications subject to change without notice. this product has been designed and qualified for the consumer market. qualifications standards can be found on ir?s web site. ir world headquarters: 233 kansas st., el segundo, california 90245, usa tel: (310) 252-7105 tac fax: (310) 252-7903 visit us at www.irf.com for sales contact information . 11/04
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