2015. 10. 27 1/10 semiconductor technical data KIC6961T analog cmos integrated circuits revision no : 3 description the KIC6961T is integrated power switches optimized for usb and other hot-swap applications with a programmable current limit feature. currentlimit accuracy ? 10 % can be achieved at high current-limit settings. the family of devices complies with usb 2.0 and is available with high polarity of enable input. they offer current and thermal limiting and shortcircuit protection as well as controlled rise time and under-voltage lockout functionality. features h single usb port power switches with discharge h operating input voltage range 2.7v to 5.5v h up to 2.1a maximum load current h adjustable current limit : 0.5a to 2.6a h reverse current blocking h fault report with blanking time(7ms) h 100m ? power mosfet h qualified to aec-q100. dim millimeters a b d e ts6 (sot23-6) 2.9 0.2 1.6+0.2/-0.1 0.70 0.05 0.4 0.1 2.8+0.2/-0.3 1.9 0.2 0.95 0.16 0.05 0.00-0.10 0.25+0.25/-0.15 c f gh i j k 0.60 l0 . 5 5 a f g g d k k b e c l h j j i 23 5 16 4 + _ + _ + _ + _ + _ maximum ratings (ta=25 ? ) 961 lot no. marking v in gnd v en v out i lmit flg type name (top view) 123 654 pin configurations ts6(sot23-6) characteristic symbol rating unit input voltage v in 6.5 v output voltage v out 6.5 v power dissipation (no heatsink) p d * 900 mw operating junctiontemperature tj -40 ~ 125 ? storage temperature t stg -55 ~ 150 adjustable 1 - channel current limited power switch * note ) package mounted on a ceramic board (600mm 2 ? 0.8mm) downloaded from: http:///
2015. 10. 27 2/10 KIC6961T revision no : 3 block diagrampin descriptions v in flg v en gnd uvlo reverse blocking driver thermal protection short circuit protection current sense current limit discharge control deglitch v out i lmit typical application circuit gnd v out v in flgv en 10k on off power supply 2.7v to 5.5v load + + r lmit i lmit pin number pin name descriptions 1 v in voltage input pin 2 gnd ground 3 v en enable input (active high) 4 flg over-current and over-temperature fault report pin (open drain) 5 i lmit current limit set pin ? external resistor used to set current limit threshold 6 v out voltage output pin downloaded from: http:///
2015. 10. 27 3/10 KIC6961T revision no : 3 electrical characteristics (v in =5v, ta=25 ? , unless otherwise stated) characteristics symbol test conditions min. typ. max. units supply input uvlo v uvlo v in rising 1.6 2.2 2.5 v input uvlo hysteresis v in decreasing 50 100 150 mv input shutdown current i shdn disabled, i out = 0a 0.2 0.5 1.0 u input quiescent current i q enabled, i out = 0a 20 45 70 u input leakage current i leak disabled, v out grounded - 0.1 1 u power switch switch on-resistance r ds(on) i out = 1.0a, ta=25 ? - 100 - m ? i out = 1.0a, -40 ? ? ta ? 85 ? - - 150 m ? output turn-on rise time t r c l =1 ? , r load =10 ? - 0.6 1.5 n t output turn-off fall time t f c l =1 ? , r load =10 ? - 0.2 0.4 n t current limit current limit i lmit r lmit =10 ? 2.335 2.594 2.853 a r lmit =20 ? 1.121 1.246 1.370 a r lmit =49.9 ? 0.419 0.477 0.534 a enable pin en input logic low voltage v il v in = 2.7v to 5.5v - - 0.8 v en input logic high voltage v ih v in = 2.7v to 5.5v 2 - - v en input leakage i sink v en =5v - - 1 u output discharge discharge time t dis c l =100 ? , r load =10 ? 1 3 6 ms reverse voltage protection reverse leakage current i rev disabled, v in =0v, v out =5v, i rev @v in - 0.1 1 u fault flag flg blanking time t blank c in =10 ? , c l =22 ? 4 7 15 ms thermal shutdown thermal shutdown threshold t shdn enabled, r load =1 ? 130 150 170 ? thermal shutdown hysteresis t hys - - 25 - ? recommended operating conditions (ta=25 ? , unless otherwise stated) symbol parameter min. max. units v in input voltage 2.7 5.5 v v en enable voltage 0 5.5 v v ih high-level input voltage on en 2.0 v in v v il low-level input voltage on en 0 0.8 v r lmit current-limit threshold resistor range (1% initial tolerance) 10 49.9 ? downloaded from: http:///
2015. 10. 27 4/10 KIC6961T revision no : 3 curren limit threshold vs. r lmit i lmit , current limit threshold (a) 20 30 60 01 0 4 05 0 0 0.80.4 1.61.2 2.0 2.82.4 r lmit , current limit resistor ( ? ) current- limit threshold programming (cont.) when a heavy load or short circuit situation occurs while the switch is enabled, large transient current may flow through the device. KIC6961T includes a current-limit circuitry to prevent these large currents from damaging the mosfet switch and thehub downstream ports. especially, the KIC6961T is proposed to have current limit flexibility for customer. i lmit pin is available to connect pull down resistor to ground, which participate to the current threshold adjustment. the KIC6961T provides an adjustable current limit threshold between 0.5a and 2.6a (typ.) via an external resistor, r lmit , between 10 ? and 49.9 ? . it s strongly recommended to use 0.1 or 1% resistor tolerance to keep the over current accuracy. once the current limit threshold is exceeded, the device enters constant-current mode until either thermal shutdown occurs or t he fault is removed. downloaded from: http:///
2015. 10. 27 5/10 KIC6961T revision no : 3 limit current v en v en vout i out flg i out flg 7ms 7ms 7ms output short output short 7ms nomal current 7ms normal current 7ms limit current condition flg remark over - load v in - v out ! 0.5v active l short circuit - active l ? flg response condition over current & short circuit protection timing chart [figure 1. over current protection on power switch] [figure 2. short circuit protection on power switch] downloaded from: http:///
2015. 10. 27 6/10 KIC6961T revision no : 3 ? ? actual waveform r lmit over load short circuit 10 ? 20 ? 49.9 ? 100ms/div v out 5v/div flg 5v/divi in 2a/div 100ms/div v out 5v/div flg 5v/divi in 1a/div 100ms/div v out 5v/div flg 5v/divi in 500ma/div 100ms/div v out 5v/div flg 5v/divi in 2a/div v in =5v c in =10 ? c out =100 ? 100ms/div v out 5v/div flg 5v/divi in 1a/div v in =5v c in =10 ? c out =100 ? 100ms/div v out 5v/div i in 500ma/div v in =5v c in =10 ? c out =100 ? v in =5v r l =1.5 ? c in =10 ? c out =100 ? v in =5v r l =3 ? c in =10 ? c out =100 ? v in =5v r l =4 ? flg 5v/div c in =10 ? c out =100 ? downloaded from: http:///
turn-on delay and rise time turn-off delay and fall time 2015. 10. 27 7/10 KIC6961T revision no : 3 v en v out t d(off) t d(off) t f 50% 50% 10% 10% 90% 90% t r [figure 3 delay time] ? ? actual waveform 2.0ms/div 2.0ms/div 40.0ms 2.00ms 40.0ms 400 k v in =5v r lmit =20 ? r out =5 ? c l =100 ? v en 5v/div v out 5v/div i in 1a/div v in =5v r lmit =20 ? r out =0 ? c l =100 ? v in =5v r lmit =20 ? c l =100 ? v in =5v r lmit =20 ? c l =100 ? v in =5v r lmit =20 ? c l =100 ? v en 5v/div i in 1a/div v out 5v/div flg 5v/div i in 1a/div v out 5v/div flg 5v/div i in 1a/div v out 5v/div flg 5v/div i in 1a/div v in =5v r lmit =20 ? r out =5 ? c l =100 ? v en 5v/div v out 5v/div i in 1a/div (7) enable function timing chart (8) device enabled into short-circuit (9) no load to 1 ? transient response (10) short-circuit limit response (11) extended short-circuit into termal cycle downloaded from: http:///
2015. 10. 27 8/10 KIC6961T revision no : 3 (12) static drain-source on-state resistance vs. ambient temerature static drain-source on-state resistance (m ) 01 0 0 -60 -40 -20 20 40 60 80 50 100 9080 70 60 110 120 130 140 150 160 170 180 ambient temperature ( ) v in =2.7v v in =3.3v v in =5v downloaded from: http:///
2015. 10. 27 9/10 KIC6961T revision no : 3 functional description1. over-current and short circuit protection an internal sensing fet is employed to check for over-current conditions. when an over-current condition is detected, thedevice maintains a constant output current and reduces the output voltage accordingly. complete shutdown occurs only if the fault stays long enough to activate thermal limiting. 2. thermal protection thermal protection prevents the ic from damage when the die temperature exceeds safe margins. this mainly occurs whenheavy-overload or short-circuit faults are present for extended periods of time. the KIC6961T implements a thermal sensing to monitor the operating junction temperature of the power distribution switch. once the die temperature rises to approximately 150 ? c, the thermal protection feature gets activated as follows: the internal thermal sense circuitry turns the power switch off and the flg output is asserted thus preventing the power switch from damage. hysteresis in the thermal sense circuit allows thedevice to cool down to approximately 25 ? c before the output is turned back on. this built-in thermal hysteresis feature is an excellent feature, as it avoids undesirable oscillations of the thermal protection circuit. the switch continues to cycle in th is manner until the load fault is removed, resulting in a pulsed output. the flg open-drain output is asserted when an over-current occurs with 7-ms deglitch. 3. under-voltage lockout (uvlo) under-voltage lockout function (uvlo) guarantees that the internal power switch is initially off during start-up. the uvlofunctions only when the switch is enabled. even if the switch is enabled, the switch is not turned on until the power supply ha s reached at least 2.2v. whenever the input voltage falls below approximately 2.2v, the power switch is turned off. thisfacilitates the design of hot-insertion systems where it is not possible to turn off the power switch before input power is removed. 4. reverse current protection in a normal mosfet switch, current can flow in reverse direction (from the output side to the input side) when the output sidevoltage is higher than the input side, even when the switch is turned off. a reverse-current blocking feature is implemented in the KIC6961T to prevent such back currents. this circuit is activated by the difference between the output voltage and the inpu t voltage. when the switch is disabled, this feature blocks reverse current flow from the output back to the input. 5. discharge function when enable is de-asserted, the discharge function is active. the output capacitor is discharged through an internal nmos thathas a discharge resistance of 100 ? . hence, the output voltage drops down to zero. the time taken for discharge is dependent on the rc time constant of the resistance and the output capacitor. 6. flg response the flg open-drain output goes active low for any of the two conditions: over-current or over-temperature. the time from when a fault condition is encountered to when the flg output goes low is 7-ms (typ). the flg output remains low until bothover-current and over-temperature conditions are removed. connecting a heavy capacitive load to the output of the device can cause a momentary over-current condition, which does not trigger the flg due to the 7-ms deglitch timeout. the KIC6961T is designed to eliminate erroneous over-current reporting without the need for external components, such as an rc delay network. downloaded from: http:///
2015. 10. 27 10/10 KIC6961T revision no : 3 applications information1. supply filtering placing a high-value electrolytic capacitor on the input (10uf minimum) and output pin (100uf) is recommended when the output load is heavy. this precaution also reduces power-supply transients that may cause rining on the input. 2. enable input v en must be driven logic high for a clearly defined input. floating the input may cause unpredictable operation. v en should not be allowed to go negative with respect to gnd. downloaded from: http:///
|
