unisonic technologies co., ltd us16855 preliminary cmos ic www.unisonic.com.tw 1 of 8 copyright ? 2011 unisonic technologies co., ltd qw-r502-558.a dual high-side switch for usb application ? description the utc us16855 is a dual channel power switch with independent enable and flag functions optimized for bus-powered universal serial bus (usb) and self-powered applications. this product satisfies usb voltage drop requirement with soft start which eliminates the moment ary voltage drop on the upstream port that may occur. in addition, the utc us16855 is equipped with over-temperature and over-current detectors and eac h flag output is available to indicate fault conditions independently to the usb controller. the utc us16855 is available in active-high versions in 8-pin sop package. ? features * 4v ~ 5.5v operating range * two p-channel power mosfet control switch * over-current protection * under-voltage lockout circuit * thermal shutdown circuit * soft-start circuit * flag indicates fault conditions sop-8 ? ordering information ordering number lead free halogen free package packing us16855l-s08-r us16855g-s08-r sop-8 tape reel us16855l-s08-t US16855G-S08-T sop-8 tube note: xx: output voltage, refer to marki ng information. us16855g-xx-s08-r (1)packing type (2)package type (3)output voltage code (1) r: tape reel, t: tube (2) s08: sop-8 (3) xx: refer to marking information (4) halogen free, l: lead free (4)halogen free
us16855 preliminary cmos ic unisonic technologies co., ltd 2 of 8 www.unisonic.com.tw qw-r502-558.a ? pin configuration ? pin description pin no. pin name description 1, 4 ctl1/ctl2 control : ttl input 2, 3 flg1/flg2 over current detect flag : active-l, nch open-drain 6 gnd ground 7 in power supply : source of mosfet 8, 5 out1/out2 output of sw itch : drain of mosfet ? description of utc us16855 function ctl input logic switch operati on with over-current detect ?h? active switch off regardless of ctl input ? truth table (h: high, l: low, on: turn on, off: turn off, x: h or l) ctl1 flg1 out1 ctl2 flg2 out2 operating mode h h on h h on normal mode h h on l h off only out1 is on l h off h h on only out2 is on l h off l h off standby mode h l off h h on only out1 is over-current detect h h on h l off only out2 is over-current detect x l off x l off tsd mode x l off x l off uvlo mode
us16855 preliminary cmos ic unisonic technologies co., ltd 3 of 8 www.unisonic.com.tw qw-r502-558.a ? block diagram current limit current limit gate control gate control uvlo thermal shutdown flag logic flag logic control control ctl1 ctl2 gnd flg2 flg1 out2 out1 in 2 8 7 5 3 1 6 4
us16855 preliminary cmos ic unisonic technologies co., ltd 4 of 8 www.unisonic.com.tw qw-r502-558.a ? absolute maximum rating (t a =25c, unless otherwise specified) parameter symbol ratings unit input voltage v in ?0.3 ~ +6 v flag voltage v flg ?0.3 ~ +6 v control input voltage v ctl ?0.3 ~ +6 v output voltage v out v in + 0.3 v flag current i flg 50 ma +0.5 dc v in = v ctl =5 v ?0.1 output current pulse width 100 s single pulse i out +3 a power dissipation p d 300 mw operating temperature t a ?40 ~ +85 c storage temperature t stg ?55 ~ +150 c notes: 1. absolute maximum ratings are those values beyond which the device could be permanently damaged. absolute maximum ratings are stress ratings only and functional device operation is not implied. 2. the thermal shutdown circuit ( operating temperature is more than 1 50 c typ.) builds in this product. ? recommended operating range parameter symbol ratings unit input voltage v in +4 ~ +5.5 v operating temperature t a 0 ~ +70 c ? electrical characteristics (t a = +25c, v in = +5v, unless otherwise specified) parameter symbol test conditions min typ max unit dc characteristics v ctl = 0v (both pin 1 & pin 4), out = open 1 5 a circuit current i dd v ctl = v in , out = open 1 1.5 ma low-level input voltage v il ctl pin 1.0 v high-level input voltage v ih ctl pin 2.0 v v ctl = 0v 0.01 1 a input current of ctl pin i ctl v ctl = v in 0.01 1 a output mosfet on resistance r on t a = 0 ~ +70 c, i out = 500 ma 100 130 m ? output leak current i o leak 10 a over current detect threshold i th t a = 0 ~ +70 c 0.6 0.9 1.25 a flag output resistance r onf i l = 10 ma 10 25 ? flag leak current i o leak f v flag = 5 v 0.01 1 a v in : up 2.2 2.5 2.8 v v in : down 2.0 2.3 2.6 v operating voltage of under voltage locked out circuit v uvlo hysteresis 0.1 0.2 0.3 v ac characteristics output transition rising time t rise r l = 10 ? each output 2.5 12 ms output transition falling time t fall r l = 10 ? each output 10 s over current detect delay time t over 5 20 s ctl input low-level time t ctl ctl : h l h 20 s
us16855 preliminary cmos ic unisonic technologies co., ltd 5 of 8 www.unisonic.com.tw qw-r502-558.a ? timing diagram output transition rising time (at on)/ou tput transition falling time (at off) at the timing of ctl changing ?l? to ?h?/?h? to ?l? for utc us16855 over current detect delay time/ctl input low-level time for utc us16855 over current detect dela y time/ctl input low-level time for utc us16855 i out v out flg ctl t over 90% 90% t ctl 90% i th
us16855 preliminary cmos ic unisonic technologies co., ltd 6 of 8 www.unisonic.com.tw qw-r502-558.a ? function description under voltage locked out uvlo prevents malfunction of the switch because of voltage variation. when i nput voltage exceeds 2.5v (typical), the output mosfet turns on. if input vo ltage drops below 2.3v (typical), uv lo shuts off the bot h output mosfet switches and signals the flag. power on and off the utc us16855 performs a soft-start operation on power applicatio n, which is to prevent an over-current or inrush-current from flowing through the switch from in to outx towards to the load, while the high-capacity capacitor is connected to the outx. over current detect the specification of over cu rrent detect is 0.6 ~ 1.25 a (typ. 900ma) in this ic. ( 500 ma max. in usb standard) this function is that flag-pin turns to low-level and reports to the usb controller when over current is detected. at this time, output of ic is operated as followed. output turns to off, and isn't based on the state of ctl-pin. when ctl-pin turns to non-active, flg-pin returns to high-level and output-pin turn to off-state. immediately the controller should be inputted non-active leve l to ctl-pin after detecting flg = ?l? not to reach to the state of thermal shutdown. then, in the case of flg-pin is high-level and ctl-pi n is active level, output -pin turns to on-state. to prevent from detecting wrongly the current to the moment, over current detect delay time is set up. this delay time is 10 ms (typ.). over current detect over current detect threshold 5v 5v 5v 5v gnd gnd gnd in (input) flg (output) ctl (input) i out out (output) gnd
us16855 preliminary cmos ic unisonic technologies co., ltd 7 of 8 www.unisonic.com.tw qw-r502-558.a ? function description(cont.) thermal shutdown the utc us16855 is internally protected against excessive po wer dissipation by thermal shutdown protection circuit. if device junction temperature ri se above approximately 150 , both swit ches are turned off, both fault flag outputs are activated, and they goes low. hysteresis ensures that both switches turned off by thermal shutdown will not be turned on again until the die temperatur e is reduced to 145 . when the thermal shutd own circuit is activated, the output pins are in the o ff status. however, the utc us16855 enters the standby status when ctl pins are all inactive. 5v 5v gnd gnd gnd 5v in (input) flg (output) ctl (input) out (output) thermal shutdown operating temperature (up) thermal shutdown operating temperature (down) non-stand-by stand-by tch 5v gnd ? test circuit
us16855 preliminary cmos ic unisonic technologies co., ltd 8 of 8 www.unisonic.com.tw qw-r502-558.a ? typical application circuit utc assumes no responsibility for equipment failures that result from using products at values that exceed, even momentarily, rated values (such as maximum ratings, operating condition ranges, or other parameters) listed in products specifications of any and all utc products described or contained herein. utc products are not designed for use in life support appliances, devices or systems where malfunction of these products can be reasonably expected to result in personal injury. reproduction in whole or in part is prohibited without the prior written consent of the copyright owner. the information presented in this document does not form part of any quotation or contract, is believed to be accurate and reliable and may be changed without notice.
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