ZXGD3108N8 document number ds36530 rev. 1 - 2 1 of 10 www.diodes.com may 2014 ? diodes incorporated ZXGD3108N8 a product line o f diodes incorporated 40v active or-ing mosfet controller in so8 description ZXGD3108N8 is a 40v active or -ing mosfet controller designed for driving a very low r ds(on) power mosfet as an ideal diode. this replaces the standard rectifier to reduce the forward voltage drop and overall increase the power transfer efficiency. the ZXGD3108N8 can be used on both high-side and low-side power supply units (psu) with rails up to 40v. it enables very low r ds(on) mosfets to operate as ideal diodes as the turn-off threshold is only -3mv with 2mv tolerance. in the typical 12v configuration, the standby power consumption is <5mw as the low quiescent supply current is <400a. during psu faul t condition, the or?ing controller detects the power reduction and rapidly turns off the mosfet in <600ns to block reverse current flow and avoid the common bus voltage dropping. applications active or?ing controller in: ? (n + 1) redundant power supplies ? telecom and networking ? data centers and servers features ? active or?ing mosfet controller for high- or low-side psu ? ideal diode to reduce forward voltage drop ? -3mv typical turn-off threshold with 2mv tolerance ? 40v drain voltage rating ? 25v v cc rating ? <5mw standby power with quiescent supply current <400a ? <600ns turn-off time to minimize reverse current ? totally lead-free & fully rohs compliant (notes 1 & 2) ? halogen and antimony free. ?green? device (note 3) mechanical data ? case: so-8 ? case material: molded plasti c. ?green? molding compound ul flammability rating 94v-0 ? moisture sensitivity: level 1 per j-std-020 ? terminals: finish - matte ti n plated leads, solderable per mil-std-202, method 208 ? weight: 0.074 grams (approximate) ordering information (note 4) product marking reel size (inches) tape width (mm) quantity per reel ZXGD3108N8tc zxgd 3108 13 12 2,500 notes: 1. no purposely added lead. fully eu directiv e 2002/95/ec (rohs) & 2011/6 5/eu (rohs 2) compliant. 2. see http://www.diodes.com/quality/lead_free.html for more in formation about diodes incorporated?s definitions of halogen- an d antimony-free, "green" and lead-free. 3. halogen- and antimony-free "green? products are defined as those which contain <900ppm br omine, <900ppm chlorine (<1500ppm t otal br + cl) and <1000ppm antimony compounds. 4. for packaging details, go to our website at http://www.diodes.com/p roducts/packages.html. marking information pin name pin function dnc do not connect gnd power ground gate gate drive drain drain sense v cc power supply zxgd = product type marking code, line 1 3108 = product type marking code, line 2 yy = year (ex: 14 = 2014) ww = week (01 - 53) zxgd 3108 y y w w top view so-8 power supply gate gnd vcc dnc drain dnc vcc gnd
ZXGD3108N8 document number ds36530 rev. 1 - 2 2 of 10 www.diodes.com may 2014 ? diodes incorporated ZXGD3108N8 a product line o f diodes incorporated absolute maximum ratings (voltage relative to gnd, @ t a = +25c, unless otherwise specified.) characteristic symbol v alue unit supply voltage v cc 25 v drain pin voltage v d -3 to 40 v gate output voltage v g -3 to v cc + 3 v gate driver peak source current i source 2 a gate driver peak sink current i sink 5 a thermal characteristics (@ t a = +25c, unless otherwise specified.) characteristic symbol v alue unit power dissipation linear derating factor (note 5) p d 490 3.92 mw mw/c (note 6) 655 5.24 (note 7) 720 5.76 (note 8) 785 6.28 thermal resistance, junction to ambient (note 5) r ja 255 c /w (note 6) 191 (note 7) 173 (note 8) 159 thermal resistance, junction to lead (note 9) r jl 135 c /w operating and storage temperature range t j , t stg -50 to +150 c esd ratings (note 10) characteristic symbol v alue unit jedec class electrostatic discharge - human body model esd hbm 2,000 v 3a electrostatic discharge - machine model esd mm 200 v b notes: 5. for a device surface mounted on minimu m recommended pad layout fr4 pcb with high coverage of single sided 1o z copper, in still air conditions; the device is measured when operating in a steady-state condition. 6. same as note (5), except pins 2 & 3 (gnd) and pins 5 & 6 (v cc ) are both connected to separate 5mm x 5mm 1oz copper heat-sinks. 7. same as note (6), except both heat-sinks are 10mm x 10mm. 8. same as note (6), except both heat-sinks are 15mm x 15mm. 9. thermal resistance from junction to solder-point at the end of each lead on pins 2 & 3 (gnd) and pins 5 & 6 (v cc ). 10. refer to jedec specification jesd22-a114 and jesd22-a11 thermal derating curve 0 20 40 60 80 100 120 140 160 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 15mm x 15mm 5mm x 5mm minimum layout derating curve junction temperature (c) max power dissipation (w) 10mm x 10mm
ZXGD3108N8 document number ds36530 rev. 1 - 2 3 of 10 www.diodes.com may 2014 ? diodes incorporated ZXGD3108N8 a product line o f diodes incorporated electrical characteristics (@ v cc = 12v, t a = +25c, unless otherwise specified.) characteristic symbol min typ max unit test condition input supply operating supply voltage v cc 4 ? 20 v quiescent current i q ? 200 400 a -0.6v v drain 30v gate driver gate peak source current i source ? 0.66 ? a c l = 47nf gate peak sink current i sink ? 3.3 ? gate peak source current (note 11) i source 1 ? ? a v gate = 5v & v drain = -1v gate peak sink current (note 11) i sink 1.8 ? ? a v gate = 5v & v drain = 1v detector under dc condition turn-off threshold voltage v t -5 -3 -1 mv v g 1v load: 50nf capacitor connected in parallel with 50k ? resistor gate output voltage v g(off) ? 0.1 0.3 v v drain 0mv v g 9 9.2 v drain = -8mv v g(off) ? 0.1 0.3 v drain 0mv & v cc = 4v v g 3 3.2 ? v drain = -8mv & v cc = 4v v g(off) ? 0.1 0.3 v drain -8mv & v cc = 20v v g 19 19.2 ? v drain = -8mv & v cc = 20v switching performance turn-on propagation delay t d(rise) ? 400 ? ns c l = 47nf rise and fall measured 10% to 90% refer to application test circuit below gate rise time t r ? 695 ? turn-off propagation delay t d(fall) ? 400 ? gate fall time t f ? 131 ? note: 11. measured under pulsed conditions. pulse width = 300 s. duty cycle 2%. pin functions pin number pin name pin function and description 1, 7 dnc do not connect leave pin floating. 2, 3 gnd ground connect this pin to the mosfet source terminal and ground reference point. 4 gate gate drive this pin sources (i source ) and sinks ( i sink ) current into the mosfet gate. the turn on time of the mosfet can be programmed through an external gate resistor (r g ). 5, 6 v cc power supply this supply pin should be cl osely decoupled to ground with a x7r type capacitor. 8 drain drain sense connect this pin to the mosfet drain terminal to detect the change in drain-source voltage. gate gnd vcc dnc drain dnc vcc gnd
ZXGD3108N8 document number ds36530 rev. 1 - 2 4 of 10 www.diodes.com may 2014 ? diodes incorporated ZXGD3108N8 a product line o f diodes incorporated layout considerations the gate pin should be close to the mosfet gate to minimize trace resistance and induc tance to maximize switching performance. whilst the v cc to gnd pin needs an x7r type capacitor clos ely decoupling the supply. trace widths should be maximized in the high current pa ths through the mosfet and ground return in order to minimize the effect s of circuit resistance and induct ance; also, the ground return loo p should be as short as possible. for thermal consideration, the main heat path is from pins 2 & 3 (gnd) and pins 5 & 6 (v cc ). for best thermal performance, the copper area connected to pins 2 & 3 (gnd) and pins 5 & 6 (v cc ) should be maximised. active or?ing or (n+1) redundancy application critical systems require fault-tolerant po wer supply that can be achieved by paralle ling two or more psus into (n+1) redundancy configuration. during normal operation, usually all psus equally share the load for maximum reliability. if one of the psu is unplugged or fa ils, then the other psus fully support the load. to avoid the faulty psu from a ffecting the common bus, then an or-ing rectifier blocks the reverse current flow into the faulty psu. likewise during hot-swapping, the or?ing rectif iers isolate a psu?s discharged output capacitors from the commo n bus. as the load current is in the tens of amps then a standard rect ifier has a significant forward voltage drop. this both wastes power and significantly drops the potential on low voltage rails. hence, very low r ds(on) power mosfets can replace the standard rectifiers and the zxgd3108 controls the mosfet as an ideal diode. functional block diagram gate vcc gnd driver zxgd3108 + differential amplifier - threshold voltage drain the device is comprised of a differential amplifier and high curr ent driver. the differential amplifier acts as a detector and monitors the drain-to- gnd pin voltage difference. when this differ ence is less than the threshold voltage (v t ) then a positive output voltage approaching v cc is given on the gate pin. conversely, when the drain-to- gnd pin voltage difference is greater than v t , then gate pin voltage is rapidly reduced towards the gnd voltage.
ZXGD3108N8 document number ds36530 rev. 1 - 2 5 of 10 www.diodes.com may 2014 ? diodes incorporated ZXGD3108N8 a product line o f diodes incorporated typical application circuits the focus application of the zxgd3108 or?ing controller is for redundant low-side -12v power supply rail. example of the zxgd3108 or?ing controller in a redundant high-side +12v power supply rail with the addition of a v cc supply.
ZXGD3108N8 document number ds36530 rev. 1 - 2 6 of 10 www.diodes.com may 2014 ? diodes incorporated ZXGD3108N8 a product line o f diodes incorporated operation in typi cal application the zxgd3108 operation is described step-by-step with reference to the typical application circ uits and the timing diagram belo w: 1. the zxgd3108 differential amplifier moni tors the mosfet?s drain-source voltage (v ds ). 2. at system start up, the mosfet body diode is forced to conduct current from the input psu to the load and v ds is approximately -0.6v as measured by the differential amplifier between drain-to-gnd pins. 3. as v ds < v t (threshold voltage), then the differential am plifier outputs a positive voltage approaching v cc with respect to gnd. this feeds the driver stage from which the gate pin voltage rises towards v cc . 4. the sourcing current out of the gate pin drives the mosfet gate to enhance the channel and turn it on. 5. if a short condition occurs on the input psu, it causes the mosfet v ds to increase. 6. when v ds > v t , then the differential amplifier?s output goes to gnd and the driv er stage rapidly pulls the gate pin voltage to gnd, turning off the mosfet channel. this prevents high reverse current flow from the load to the psu which could pull down the common bus voltage causing catastrophic system failure.
ZXGD3108N8 document number ds36530 rev. 1 - 2 7 of 10 www.diodes.com may 2014 ? diodes incorporated ZXGD3108N8 a product line o f diodes incorporated typical electrical characteristics (@ t a = +25c, unless otherwise specified.) -10-9-8-7-6-5-4-3-2-1 0 0 2 4 6 8 10 12 14 16 18 20 -3.0 -2.5 -2.0 -1.5 -1.0 -0.5 0.0 0 2 4 6 8 10 -50 0 50 100 150 -2.0 -1.8 -1.6 -1.4 -1.2 -1.0 -0.8 -0.6 -0.4 -0.2 0.0 -50 -25 0 25 50 75 100 125 150 400 800 1200 1600 2000 0 20406080100 0 100 200 300 400 500 -10-9-8-7-6-5-4-3-2-1 0 0 2 4 6 8 10 12 14 16 18 20 v cc = 5v capacitive load and 50k pull down resistor v cc = 20v v cc = 12v v cc = 10v transfer characteristic v g gate voltage (v) v d drain voltage (mv) t a = 150c t a = 25c t a = 85c t a = 125c t a = -50c transfer characteristic v g gate voltage (v) v d drain voltage (mv) v cc = 12v 50k pull down v cc = 12v v g = 1v 50k pull down drain sense voltage vs temperature v d drain voltage (mv) temperature (c) t off = t d2 + t f t on = t d1 + t r switching vs temperature switching time (ns) temperature (c) v cc = 12v c l =47nf v cc = 5v v cc = 10v v cc = 12v v cc = 20v supply current vs capacitive load capacitance (nf) supply current (ma) f=250khz capacitive load only v cc = 5v v cc = 20v v cc = 12v v cc = 10v transfer characteristic v g gate voltage (v) v d drain voltage (mv)
ZXGD3108N8 document number ds36530 rev. 1 - 2 8 of 10 www.diodes.com may 2014 ? diodes incorporated ZXGD3108N8 a product line o f diodes incorporated typical electrical characteristics (cont.) (@ t a = +25c, unless otherwise specified.) -1.0 -0.5 0.0 0.5 1.0 1.5 2.0 -2 0 2 4 6 8 10 12 -1.0 -0.5 0.0 0.5 1.0 1.5 2.0 -2 0 2 4 6 8 10 12 1 10 100 300 600 900 1200 -1012345 0.0 0.2 0.4 0.6 0.8 1.0 1 10 100 0 2 4 10 100 1000 10000 100000 0.1 1 10 100 -150 -100 -50 0 50 100 150 -150 -100 -50 0 50 100 150 54 53 52 51 50 0 -1 -2 -3 -4 -5 v=12v c l =47nf v d switch off speed gate voltage (v) time (us) v g drainvoltage (mv) drain voltage (mv) v=12v c l =47nf v g v d switch on speed gatevoltage (v) time (us) v cc =12v t on = t d1 + t r t off = t d2 + t f switching vs capacitive load time (ns) capacitance (nf) sink current time scale (us) gate drive sink current (a) v=12v c l =47nf i source i sink gate drive current gate drive source current (a) source current time scale(us) v cc =12v -i sink gate current vs capacitive load peak drive current (a) capacitance (nf) i source c l =100nf c l =47nf c l =10nf c l =4.7nf c l =1nf v cc =12v supply current vs frequency frequency (hz) supply current (ma)
ZXGD3108N8 document number ds36530 rev. 1 - 2 9 of 10 www.diodes.com may 2014 ? diodes incorporated ZXGD3108N8 a product line o f diodes incorporated package outline dimensions please see ap02002 at http://www.diodes.com /datasheets/ap02002.pdf for latest version. suggested pad layout please see ap02001 at http://www.diodes.com/dat asheets/ap02001.pdf for the latest version. so-8 dim min max a - 1.75 a1 0.10 0.20 a2 1.30 1.50 a3 0.15 0.25 b 0.3 0.5 d 4.85 4.95 e 5.90 6.10 e1 3.85 3.95 e 1.27 typ h - 0.35 l 0.62 0.82 0 8 all dimensions in mm dimensions value (in mm) x 0.60 y 1.55 c1 5.4 c2 1.27 x c1 c2 y gauge plane seating plane detail ?a? detail ?a? e e1 h l d e b a2 a1 a 45 7 ~ 9 a3 0.254
ZXGD3108N8 document number ds36530 rev. 1 - 2 10 of 10 www.diodes.com may 2014 ? diodes incorporated ZXGD3108N8 a product line o f diodes incorporated 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 incor porated convey any license under its patent or trademark rights, nor the rights of others. any customer or user of this document or products described herein in such applica tions shall assume all risks of such use and will agree to hold diodes incorporated and all the companies whose pr oducts are represented on diodes incorporated website, harmless against all damages. diodes incorporated does not warrant or accept any liability w hatsoever in respect of any products purchased through unauthoriz ed sales channel. should customers purchase or use diodes inco rporated products for any unintended or un authorized application, customers shall i ndemnify and hold diodes incorporated and its representat ives harmless against all claims, damages, expenses, and attorney fees arising out of, directly or indirectly, any claim of personal injury or death a ssociated 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 more united states, international or foreign trademarks. this document is written in english but may be translated into multiple languages for reference. only the english version of t his document is the final and determinative format released by diodes incorporated. life support diodes incorporated products are specifically not authorized for use as critical co mponents in life support devices or systems without the express written approval of the chief executive offi cer 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 prope rly used in accordance with instructions for use provided in the labeling can be reasonably expected to re sult 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 for all legal, regulatory and safety-rel ated requirements concerning the ir products and any use of diodes incorporated products in such safety-critical, life support devices or systems, notwithstanding any devices- or s ystems-related information or support that may be provided by diodes incorporated. further, customers must fully indemnify diodes incorporate d and its representatives against any damages arisi ng out of the use of diodes incorporated pr oducts in such safety-critical, life suppor t devices or systems. copyright ? 2014, diodes incorporated www.diodes.com
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