AP2337 1.0a single channel curr ent-limited load switch AP2337 document number: ds35060 rev. 2 - 2 1 of 10 www.diodes.com september 2011 ? diodes incorporated new product description the AP2337 is single channel curr ent-limited integrated high- side power switches optimized for hot-swap applications. the devices have fast short-circuit response time for improved overall system robustness and provide a complete protection solution for application subject to heavy capacitive loads and the prospect of short circuit. it offers reverse current blocking, over-current, over-temperature and short-circuit protection, as well as controlled rise time and under-voltage lockout functionality. the device is available in sot23 package. pin assignments gnd ( top view ) 3 in 1 out 2 sot23 features ? input voltage rang e: 2.7v ? 5.5v ? fast short-circui t response time ? 1.5a accurate current limiting ? 110m ? on-resistance ? reverse current blocking ? built-in soft-start with 2.5ms typical turn-on time ? over current protection ? over voltage protection ? short circuit and thermal protection ? esd protection: 3kv hbm, 300v mm ? ambient temperature range: -40oc to 85c ? available in ?green? molding compound (no br, sb) ? lead free finish/ rohs compliant (note 1) ? ul recognized, file number e322375 (to be completed) ? iec60950-1 cb scheme certified (to be completed) applications ? lcd tvs & monitors ? set-top-boxes, residential gateways ? laptops, desktops, servers ? printers, docking stations, hubs ? smart phones, e-readers notes: 1. eu directive 2002/95/ec (rohs). all applicab le rohs exemptions applied. please visit our website at http://www.diodes.com/products/lead_free.html . typical application circuit 0.1f in gnd out power supply 2.7v to 5.5v load 0.1f
AP2337 1.0a single channel curr ent-limited load switch AP2337 document number: ds35060 rev. 2 - 2 2 of 10 www.diodes.com september 2011 ? diodes incorporated new product pin descriptions pin name pin number descriptions gnd 1 ground out 2 switch output pin in 3 voltage input pin function block diagram thermal sense out gnd uvlo current limit current sense discharge control driver in + - 15us deglitch time reverse voltage comparator reverse current limit 0.6ms deglitch time absolute maximum ratings symbol parameter ratings units esd hbm human body model esd protection 3 kv esd mm machine model esd protection 300 v v in input voltage 6.5 v v out output voltage v in + 0.3 v i load maximum continuous load current internal limited a t jmax maximum junction temperature 150 c t st storage temperature range (n ote 2) -65 to 150 c notes: 2. ul recognized rating from -30c to 70c (diodes qualified t st from -65c to 150c)
AP2337 1.0a single channel curr ent-limited load switch AP2337 document number: ds35060 rev. 2 - 2 3 of 10 www.diodes.com september 2011 ? diodes incorporated new product recommended operating conditions symbol parameter min max units v in input voltage 2.7 5.5 v i out output current 0 1.0 a t a operating ambient te mperature -40 85 c electrical characteristics (t a = 25 o c, v in = +5.0v, unless otherwise stated) symbol parameter test conditions (note 3) min typ. max unit v uvlo input uvlo v in rising 2.00 2.65 v i q input quiescent current above uvlo, i out = 0 65 110 a i rev reverse leakage current v in = 0v, v out = 5v, i rev at v in 0.01 0.1 a r ds ( on ) switch on-resistance v in = 5v, i out = 1a 110 140 m
v in = 3.3v, i out = 1a 140 170 i limit over-load current limit v in = 5v, v out = 4v, c l =10 f 1.1 1.5 1.9 a i os short-circuit current out connected to ground, c l =10 f 0.2 0.6 1.0 a t short short-circuit response time from v out < 0.6v to i out = 0a (out shorted to gnd) (see figure. 1)(note 7) 5 s i rocp reverse current limit above uvlo 0.3 0.5 0.7 a t trig deglitch time from reverse current trigger to mosfet turn off 0.6 ms v ovp output over-voltage trip point above uvlo (note 4) 110% 120% v in t ovp debounce time from output over- voltage to mosfet turn off 15 s t on output turn-on time (note 5) c l = 1 f, r load = 5
(uvlo to 90% v out-nom ) 1 4 ms t dis discharge time c l = 1 f, from uvlo to v out < 0.3v 500 s t shdn thermal shutdown threshold 150 c t hys thermal shutdown hysteresis 20 c ja thermal resistance junction-to- ambient (note 6) 180 o c/w notes: 3. pulse-testing techniques maintain junction temperature close to ambient temper ature; thermal effects must be taken in to account separately. 4. during output over-voltage protection, the output draws approximately 60a current. 5. since the output turn-on slew rate is dependent on input supp ly slew rate, this limit is only applicable for input supply slew rate between 5v/0.2ms to 5v/1ms. 6. device mounted on fr-4 substrate pcb, 2oz copper, with minimum recommended pad layout. 7. applicable for output voltage slew rate ? 5v/30 s. figure 1. short circuit response time
AP2337 1.0a single channel curr ent-limited load switch AP2337 document number: ds35060 rev. 2 - 2 4 of 10 www.diodes.com september 2011 ? diodes incorporated new product typical performance characteristics uvlo increasing 1ms/div uvlo decreasing 5ms/div over-load current limit short circuit current limit 50ms/div 100us/div output over voltage trip point 500us/div debounce time from output over-voltage to mosfet turn off (zoom in at red portion of previous waveform) 20us/div c l = 1 0 uf c l = 1 0 uf tovp 12 s ov trip at 114% of vin, vin=5v
AP2337 1.0a single channel curr ent-limited load switch AP2337 document number: ds35060 rev. 2 - 2 5 of 10 www.diodes.com september 2011 ? diodes incorporated new product typical performance characteristics (cont.) deglitch time from reverse current trigger to mosfet turn off reverse current limit 500us/div 500us/div output turn-on time 1ms/div discharge time 5ms/div
AP2337 1.0a single channel curr ent-limited load switch AP2337 document number: ds35060 rev. 2 - 2 6 of 10 www.diodes.com september 2011 ? diodes incorporated new product typical performance characteristics (cont.) 50 55 60 65 70 75 80 85 90 95 -20020406080 -40 ambient temperature (c) fig. 1 quiescent supply current vs. ambient temperature su p p l y c u r r ent ( a ) 50 55 60 65 70 75 80 85 90 95 -20020406080 -40 ambient temperature (c) fig. 1 quiescent supply current vs. ambient temperature s u p p l y c u r r e nt ( a ) 0 0.5 1 1.5 2 2.5 3 3. 5 2.533.544.555.5 input voltage (v) fig. 3 output turn on-time vs. input voltage c = 1f r = 5 l l 6 output turn on-time (ms) 0 20 40 60 80 100 120 140 160 180 200 -20 0 20 40 60 80 -40 ambient temperature (c) fig. 4 switch on-resistance vs. ambient temperature o n- s t a t e r e s i s t a n c e (m ) 1.4 1.41 1.42 1.43 1.44 1.45 1.46 -20 0 20 40 60 80 -40 ambient temperature (c) fig. 5 current limit trip threshold vs. ambient temperature overload current limit (a) 480 500 520 540 560 580 600 -20 0 20 40 60 80 -40 ambient temperature (c) fig. 6 reverse current limit vs. ambient temperature reverse current limit (ma)
AP2337 1.0a single channel curr ent-limited load switch AP2337 document number: ds35060 rev. 2 - 2 7 of 10 www.diodes.com september 2011 ? diodes incorporated new product application note protection features: under-voltage lockout (uvlo) whenever the input voltage falls be low uvlo threshold (~2.5v), the power switch is turned off. this facilitates the design of hot-insertion systems where it is not possible to turn o ff the power switch before input power is removed. over-current and short circuit protection an internal sensing fet is employed to check for over-curr ent conditions. unlike current-sense resistors, sense fets do not increase the series resistance of the current path. when an overcurrent condition is detected, the device 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. the different overload conditions and the corresp onding response of the AP2337 are outlined below: no conditions explanation behavior of the AP2337 1 short circuit condition at start-up output is shorted before input voltage is applied or before the part is powered up. the ic senses the short circuit and immediately clamps output current to a certain safe level namely i short 2 short-circuit or overcurrent condition short-circuit or overload condition that occurs when the part is powered up and above uvlo. ? at the instance the ov erload occurs, higher current may flow for a very short period of time before the current limit function can react. ? after the current limit function has tripped (reached the over-current trip threshold), the device switches into current limiting mode and the current is clamped at i short /i limit . 3 gradual increase from nominal operating current to i limit load increases gradually until the current-limit threshold. the current rises until i limit . once the threshold has been reached, the device switches into its current limiting mode and is clamped at i limit . reverse current protection the usb specification does not a llow an output device to source current back into the usb port. in a normal mosfet switch, current will flow in reverse direct ion (from the output side to the input side) when the output side voltage is higher than the input side. a reverse current limit feature is implemented in t he AP2337 to limit such back currents. this circuit is activated by the difference between the ou tput voltage and the input voltage (100mv typ). after the reverse current circuit has tripped (reached the reverse current tr ip threshold), the current rises until i rocp level. when the fault exists for more than 600us, output device is disabled and shutdown. this is called the "deglitch time from reverse current trigger to mosfet turn off?. recovery from irocp occurs when the output voltage falls to 101% of input voltage. over-voltage protection the device has an output over-voltage protection that triggers when the output voltage reac hes 114% (typ) of input voltage. when this fault condition stays on for longer than 15 us (this is called the ?debounce time from output over-voltage to mosfet turn off? ) output device is disabled and shutdown. recovery fr om rovp occurs when the output voltage falls to 101% of input voltage.
AP2337 1.0a single channel curr ent-limited load switch AP2337 document number: ds35060 rev. 2 - 2 8 of 10 www.diodes.com september 2011 ? diodes incorporated new product application note (cont.) thermal protection thermal protection prevents the ic from da mage when the die temperature exceeds safe margins. this mainly occurs when heavy-overload or short-circuit faults are present for extended periods of time. the AP2337 implements a thermal sensing to monitor the operating junction temperatur e of the power distribution switch. once the die temperature ri ses to approximately 150c, the thermal protection feature gets activated as follows: the internal thermal sense circuitry turns the power switch off thus preventing the power switch from da mage. hysteresis in the thermal sense circuit allows the device to cool down to approximately 20c before the output is turned back on. this built-in thermal hysteresis feature is an excelle nt feature, as it avoids undesirable oscillations of the therma l protection circuit. the switch continues to cycle in this manner until the load fault is removed, resulting in a pulsed output. discharge function when input voltage is pulled, the discharge f unction is active. the output capacitor is discharged through an internal nmos that has 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 out put capacitor. discharge time is calculated when uvlo falling threshold is reached to output voltage reaching 300mv. power dissipation and junction temperature the low on-resistance of the internal mosfet allows the sm all surface-mount packages to pass large current. using the maximum operating ambient temperature (t a ) and r ds(on) , the power dissipation can be calculated by: p d = r ds(on) i 2 finally, calculate the junction temperature: t j = p d x r ja + t a where: t a = ambient temperature c r ja = thermal resistance p d = total power dissipation ordering information ap 2337 sa - 7 7 : tape & reel package packing sa : sot23 device package code packaging (note 7) 7? tape and reel quantity part number suffix AP2337sa-7 sa sot23 3000/tape & reel -7 notes: 7. pad layout as shown on diodes inc. suggested pad la yout document ap02001, which can be found on our website at http://www.diodes.c om/datasheets/ap02001.pdf.
AP2337 1.0a single channel curr ent-limited load switch AP2337 document number: ds35060 rev. 2 - 2 9 of 10 www.diodes.com september 2011 ? diodes incorporated new product marking information 1 2 3 xx y w x ( top view ) xx : identification code w : week : a~z : 1~26 week; x : a~z : internal code y : year 0~9 a~z : 27~52 week; z represents 52 and 53 week device package identification code AP2337sa-7 sot23 km package outline dimensions sot23 sot23 dim min max typ a 0.37 0.51 0.40 b 1.20 1.40 1.30 c 2.30 2.50 2.40 d 0.89 1.03 0.915 f 0.45 0.60 0.535 g 1.78 2.05 1.83 h 2.80 3.00 2.90 j 0.013 0.10 0.05 k 0.903 1.10 1.00 k1 - - 0.400 l 0.45 0.61 0.55 m 0.085 0.18 0.11 0 8 - all dimensions in mm a m j l d f b c h k g k1
AP2337 1.0a single channel curr ent-limited load switch AP2337 document number: ds35060 rev. 2 - 2 10 of 10 www.diodes.com september 2011 ? diodes incorporated new product important notice diodes incorporated makes no warranty of any kind, express or implied, with regards to this document, including, but not limited to, the implied warranties of merchantability and fitness for a particular purpose (and their equivalents under the laws of any jurisdiction). diodes incorporated and its subsidiaries rese rve the right to make modifications, enhanc ements, improvements, corrections or ot her changes without further notice to this document and any product described herein. diodes incorporated does not assume any liability ari sing out of the application or use of this document or any product described herein; neither does diodes incorporated convey any license under its patent or trademark rights, nor the rights of others. any customer or us er of this document or products described herein in such applica tions shall assume all risks of such use and will agree to hold diodes in corporated and all the companies whose products are represented on diodes incorporated website, harmless against all damages. diodes incorporated does not warrant or accept any liability what soever in respect of any pr oducts purchased through unauthoriz ed sales channel. should customers purchase or use diodes in corporated products for any unintended or unauthorized application, customers shall i ndemnify and hold diodes incorporated and its representatives harmless agai nst all claims, damages, expenses, and attorney fees arising out of, directly or indirectly, any claim of personal injury or death associated with such unintended or unauthorized application. products described herein may be covered by one or more united states, international or foreign patents pending. product names and markings noted herein may also be covered by one or mo re united states, international or foreign trademarks. life support diodes incorporated products are specifically not authorized for use as critical components in life support devices or systems without the express written approval of the chief executive officer of diodes incorporated. as used herein: a. life support devices or syst ems are devices or systems which: 1. are intended to implant into the body, or 2. support or sustain life and whose failure to perform when prop erly used in accordance with instructions for use provided in the labeling can be reasonably expected to result in significant injury to the user. b. a critical component is any component in a life support devic e or system whose failure to perform can be reasonably expect ed to cause the failure of the life support device or to affect its safety or effectiveness. customers represent that they have all necessary expertise in the safety and regulatory ramifications of their life support dev ices or systems, and acknowledge and agree that they are solely responsible fo r all legal, regulatory and safety -related requirements concerning their products and any use of diodes incorporated products in such safety-cri tical, life support devices or systems, notwithstanding any devic es- or systems- related information or support that may be provided by diodes inco rporated. further, customers must fully indemnify diodes inc orporated and its representatives against any damages aris ing out of the use of diodes incorporated products in such safety-critical, life su pport devices or systems. copyright ? 2011, diodes incorporated www.diodes.com
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