LNK632DG linkswitch-ii family www.powerint.com september 2009 energy-effcient, accurate cv switcher with cc control for adapters and chargers ? output power table product 3 85-265 vac adapter 1 open frame 2 LNK632DG 3.1 w 3.1 w table 1. output power table. notes: 1. minimum continuous power in a typical non-ventilated enclosed adapter measured at +50 c ambient. 2. maximum practical continuous power in an open frame design with adequate heatsinking, measured at 50 c ambient. 3. packages: d: so-8c. product highlights dramatically simplifes cv converters ? eliminates optocoupler and all secondary cv/cc control circuitry ? eliminates all control loop compensation circuitry ? enables clampless ? designs advanced performance features ? compensates for cable voltage drop ? compensates for external component temperature variations ? very tight ic parameter tolerances using proprietary trimming technology ? frequency jittering greatly reduces emi flter cost advanced protection/safety features ? auto-restart protection reduces power delivered by about 85% for output short circuit and control loop faults (open and shorted components) ? hysteretic thermal shutdown C automatic recovery reduces power supply returns from the feld ecosmart ? C energy effcient ? easily meets all global energy effciency regulations with no added components ? no-load consumption down to <30 mw at 230 vac input with bias winding ? on/off control provides constant effciency down to very light loads C ideal for eisa and energy star regulations ? no current sense resistors C maximizes effciency green package ? halogen free and rohs compliant package applications ? chargers for cell/cordless phones, pdas, mp3/portable audio devices, adapters, etc. description the LNK632DG dramatically simplifes low power cv/cc charger designs by eliminating an optocoupler and secondary control circuitry. the device uses an on/off control technique to provide very tight output voltage regulation, in addition to output current control ideal for battery charging applications. the combination of proprietary ic trimming and e-shield ? transformer construction techniques enables clampless designs with the LNK632DG when an external bias circuit is used. the device incorporates a 700 v power mosfet, a novel on/off control state machine, a high voltage switched current source for self biasing, frequency jittering, cycle-by-cycle current limit and hysteretic thermal shutdown circuitry onto a monolithic ic. figure 1. typical application C not a simplifed circuit (a) and output characteristic envelope (b). LNK632DG wide range hv dc input pi-5346-022509 d s fb bp/m i o v o 5% 18% pi-5292-120908 (a) typical application schematic (b) output characteristic
rev. c 09/09 2 LNK632DG www.powerint.com pin functional description drain (d) pin: this pin is the power mosfet drain connection. it provides internal operating current for both start-up and steady-state operation. bypass/multi-functional programmable (bp/m) pin: this pin has multiple functions: 1. it is the connection point for an external bypass capacitor for the internally generated 6 v supply. 2. it is a mode selection for the cable drop compensation. feedback (fb) pin: during normal operation, switching of the power mosfet is controlled by this pin. this pin senses the ac voltage on the bias winding. this control input regulates both the output voltage in cv mode and output current in cc mode based on the flyback voltage of the bias winding. the internal inductance correction circuit uses the forward voltage on the bias winding to sense the bulk capacitor voltage. source (s) pin: this pin is internally connected to the output mosfet source for high voltage power and control circuit common returns. figure 2 functional block diagram. figure 3. pin confguration. pi-5293-022309 source (s) leading edge blanking + - + - + - drain (d) bypass (bp/m) feedback (fb) source (s) fb out reset 6 v 5 v t sample-out v ilimit i lim v ilimit v th t sample-out v ilimit 6.5 v drive i lim dc max dc max fb current limit comparator state machine cable drop compensation sample delay thermal shutdown oscillator fault auto-restart open-loop constant current controller d q regulator 6 v pi-4907-032808 d package (so-8c) d s bp/m s s fb 8 5 7 1 4 2 s 6
rev. c 09/09 3 LNK632DG www.powerint.com LNK632DG functional description the LNK632DG combines a high voltage power mosfet switch with a power supply controller in one device. similar to the linkswitch-lp and tinyswitch-iii it uses a simple on/off control to regulate the output voltage. in addition, the switching frequency is modulated to regulate the output current to provide a constant current characteristic. the LNK632DG controller consists of an oscillator, feedback (sense and logic) circuit, 6 v regulator, over-temperature protection, frequency jittering, current limit circuit, leading-edge blanking, frequency control for constant current regulation and on/off state machine for cv control. constant current control (cc) operation as the output voltage and therefore the flyback voltage across the bias winding ramps up, the feedback pin voltage increases. the switching frequency is adjusted as the feedback pin voltage increases to provide a constant output current regulation. constant voltage (cv) operation as the feedback pin approaches v fbth from the constant current regulation mode, the power supply transitions into cv operation. the switching frequency at this point is at its maximum value, corresponding to the peak power point of the cccv characteristic. the controller regulates the feedback pin voltage to remain at v fbth using an on/off state-machine. the feedback pin voltage is sampled 2.5 m s after the turn-off of the high voltage switch. at light loads the current limit is also reduced to decrease the transformer fux density. output cable compensation this compensation provides a constant output voltage at the end of the cable over the entire load range in cv mode. as the converter load increases from no-load to the peak power point (transition point between cv and cc) the voltage drop introduced across the output cable is compensated by increasing the feedback pin reference voltage. the controller determines the output load and therefore the correct degree of compensation based on the output of the state machine. cable drop compensation for a 26 awg (0.4 w ) cable is selected with c bp = 1 m f and for a 28 awg (0.75 w ) cable with c bp = 10 m f. auto-restart and open-loop protection in the event of a fault condition such as an output short or an open loop condition the LNK632DG enters into an appropriate protection mode as described below. in the event the feedback pin voltage during the flyback period falls below 0.7 v before the feedback pin sampling delay (~2.5 m s) for a duration in excess of ~300 ms (auto-restart on- time (t ar-on ) the converter enters into auto-restart, wherein the power mosfet is disabled for 1.2 seconds (~20% auto-restart duty cycle). the auto-restart alternately enables and disables the switching of the power mosfet until the fault condition is removed. in addition to the conditions for auto-restart described above, if the sensed feedback pin current during the forward period of the conduction cycle (switch on time) falls below 120 m a, the converter annunciates this as an open-loop condition (top resistor in potential divider is open or missing) and reduces the auto-restart time from 300 ms to approximately 6 clock cycles (60 m s), whilst keeping the disable period of 1.2 seconds. this effectively reduces the auto-restart duty cycle to less than 0.05%. over-temperature protection the thermal shutdown circuitry senses the die temperature. the threshold is set at 142 c typical with a 60 c hysteresis. when the die temperature rises above this threshold (142 c) the power mosfet is disabled and remains disabled until the die temperature falls by 60 c, at which point the mosfet is re- enabled. current limit the current limit circuit senses the current in the power mosfet. when this current exceeds the internal threshold (i limit ), the power mosfet is turned off for the remainder of that cycle. the leading edge blanking circuit inhibits the current limit comparator for a short time (t leb ) after the power mosfet is turned on. this leading edge blanking time has been set so that current spikes caused by capacitance and rectifer reverse recovery time will not cause premature termination of the mosfet conduction. 6 v regulator the 6 v regulator charges the bypass capacitor connected to the bypass pin to 6 v by drawing a current from the voltage on the drain, whenever the mosfet is off. the bypass pin is the internal supply voltage node. when the mosfet is on, the device runs off of the energy stored in the bypass capacitor. extremely low power consumption of the internal circuitry allows the LNK632DG to operate continuously from the current drawn from the drain pin. a bypass capacitor value of either 1 m f or 10 m f is suffcient for both high frequency decoupling and energy storage. clampless design considerations ensure that worse-case high line, peak drain voltage is below the bv dss specifcation of the internal mosfet and ideally <650 v to allow margin for design variation.
rev. c 09/09 4 LNK632DG www.powerint.com parameter symbol conditions source = 0 v; t j = -40 to 125 c (unless otherwise specifed) min typ max units control functions output frequency f osc t j = 25 c v fb = v fbth 98 105 112 khz frequency ratio (constant current) f ratio(cc) t j = 25 c between v fb = 1.0 v and v fb = 1.6 v 1.57 1.635 1.7 frequency jitter peak-peak jitter compared to average frequency, t j = 25 c 7 % ratio of output frequency at auto-rst f osc(ar) t j = 25 c relative to f osc 12 16.5 21 % maximum duty cycle dc max (note 2,3) 55 % feedback pin voltage v fbth t j = 25 c see figure 10, c bp = 10 m f 2.015 2.040 2.065 v feedback pin voltage temperature coeffcient tc vfb -0.01 %/c feedback pin voltage at turn-off threshold v fb(ar) 0.65 0.72 0.79 v cable compensation factor fb see figure 10 c bp = 1 m f 1.06 c bp = 10 m f 1.09 absolute maximum ratings (1,5) drain voltage .................................. ......... ..............-0.3 v to 700 v drain peak current: ...................................... 232 (350) ma (4) peak negative pulsed drain current ................... ......... -100 ma (2) feedback voltage ................................................. ....... -0.3 v to 9 v feedback current ................................................. .............. 100 ma bypass pin voltage ..................................... ............. -0.3 v to 9 v storage temperature ...................................... ..... -65 c to 150 c operating junction temperature................. ...... -40 c to 150 c lead temperature (4) ....................................................... ......... 260 c notes: 1. all voltages referenced to source, t a = 25 c. 2. duration not to exceed 2 ms. 3. 1/16 in. from case for 5 seconds. 4. the higher peak drain current is allowed while the drain voltage is simultaneously less than 400 v. 5. maximum ratings specifed may be applied, one at a time without causing permanent damage to the product. exposure to absolute maximum ratings for extended periods of time may affect product reliability. thermal impedance thermal impedance: d package: ( q ja ) .......................... ........ 100 c/w (2) ; 60 c/w (3) ( q jc ) (1) ............................................... ......... 30 c/w notes: 1. measured on pin 8 (source) close to plastic interface. 2. soldered to 0.36 sq. in. (232 mm 2 ), 2 oz. (610 g/m 2 ) copper clad. 3. soldered to 1 sq. in. (645 mm 2 ), 2 oz. (610 g/m 2 ) copper clad.
rev. c 09/09 5 LNK632DG www.powerint.com parameter symbol conditions source = 0 v; t j = -40 to 125 c (unless otherwise specifed) min typ max units control functions (cont.) minimum switch on-time t on(min) t j = 25 c see note 3 700 ns feedback pin sampling delay t fb t j = 25 c see figure 10 2.35 2.55 2.75 m s drain supply current i s1 fb voltage > v fbth 260 330 m a i s2 fb voltage = vfb th -0.2, switch on-time = t on (mosfet switching at f osc ) 440 520 bypass pin charge current i ch1 v bp = 0 v -5 -3.4 -1.8 ma i ch2 v bp = 4 v -4 -2.3 -1 bypass pin voltage v bp 5.65 6.00 6.25 v bypass pin voltage hysteresis v bph 0.7 1.0 1.2 v bypass pin shunt voltage v shunt i bp = 10 ma 6.2 6.5 6.8 v circuit protection current limit i limit di/dt = 36 ma/ m s t j = 25 c 135 145 155 ma power coeffcient i 2 f i 2 f = i 2 limit(typ) x f osc(typ) t j = 25 c 0.9 x i 2 f 1.17 x i 2 f a 2 hz leading edge blanking time t leb t j = 25 c see note 3 170 215 ns thermal shutdown temperature t sd 135 142 150 c thermal shutdown hysteresis t sdh 60 c
rev. c 09/09 6 LNK632DG www.powerint.com parameter symbol conditions source = 0 v; t j = -40 to 125 c (unless otherwise specifed) min typ max units output on-state resistance r ds(on) i d = 13 ma t j = 25 c 45 53 w t j = 100 c 68 79 off-state leakage i dss1 v ds = 560 v see figure 11 t j = 125 c see note 1 50 m a i dss2 v ds = 375 v see figure 11 t j = 50 c 15 breakdown voltage bv dss t j = 25 c see figure 11 700 v drain supply voltage 50 v auto-restart on-time t ar-on v fb = 0 see note 3 300 ms auto-restart off-time t ar-off see note 3 1.2 2.0 s open-loop fb pin current threshold i ol see note 3 -120 m a open-loop on-time see note 3 60 m s notes: 1. i dss1 is the worst case off state leakage specifcation at 80% of bv dss and maximum operating junction temperature. i dss2 is a typical specifcation under worst case application conditions (rectifed 265 vac) for no-load consumption calculations. 2. when the duty-cycle exceeds dc max the LNK632DG operates in on-time extension mode. 3. this paramter is derived from characterization.
rev. c 09/09 7 LNK632DG www.powerint.com 1.2 1.0 0.8 0.6 0.4 0.2 0 -40 -15 10 35 60 85 110 135 temperature ( c) pi-5031-032808 frequency (normalized to 25 c) 1.2 1.0 0.8 0.6 0.4 0.2 0 -40 -15 10 35 60 85 110 135 temperature ( c) pi-5034-032108 feedback pin voltage (normalized to 25 c) figure 5. feedback pin voltage vs. temperature figure 4. output frequency vs. temperature. figure 8. output characteristics. figure 9. c oss vs. drain voltage. 100 150 175 200 125 0 0 4 2 8 6 10 12 14 16 18 20 drain v oltage (v) drain current (ma) pi-3927-083104 25 75 50 25 5c 100 5c drain v oltage (v) drain capacitance (pf) pi-3928-083104 0 100 200 300 400 500 600 1 10 100 1000 1.1 1.0 0.9 -50 -25 0 25 50 75 100 125 150 junction t emperature ( c) b rea kd own v o l tage (normalized to 25 c) pi-2213-012301 1.4 1.0 1.2 0.8 0.6 0.4 0.2 0 -50 0 50 100 150 t emperature (c) pi-4164-100505 current limit (normalized to 25 c) figure 7. current limit vs. temperature. figure 6. breakdown vs. temperature.
rev. c 09/09 8 LNK632DG www.powerint.com figure 10. test set-up for feedback pin meassurements. pi-5347-122208 v bp 500 1) raise v bp voltage from 0 v to 6.2 v, down to 4.5 v, up to 6.2 v 2) raise v in until cycle skipping occurs at v out to measure v fbth 3) reduce v in until cycle skipping stops at v out to measure v fbth- . cable drop compensaion factor is fb = v fbth / v fbth- 4) apply 1.5 v at v in and measure t fb delay from start of cycle falling edge to the next falling edge s d s s fb s 10 f bp + 2 v + v in + v out LNK632DG figure 11. test set-up for leakage and breakdown tests. pi-5348-122208 16 v to measure bv dss , i dss1 , and i dss2 follow these steps: 1) close s1, open s2 2) power-up v in source (16 v) 3) open s1, close s2 4) measure i/v characteristics of drain pin using the curve tracer s d s s fb s .1 f bp v in LNK632DG 5 f 50 k + curve tracer s1 s2 4 k 10 k
rev. c 09/09 9 LNK632DG www.powerint.com pi-4526-040207 d07c so-8c 3.90 (0.154) bsc notes: 1. jedec reference: ms-012. 2. package outline exclusive of mold flash and metal burr . 3. package outline inclusive of plating thickness. 4. datums a and b to be determined at datum plane h. 5. controlling dimensions are in millimeters. inch dimensions are shown in parenthesis. angles in degrees. 0.20 (0.008) c 2x 1 4 5 8 2 6.00 (0.236) bsc d 4 a 4.90 (0.193) bsc 2 0.10 (0.004) c 2x d 0.10 (0.004) c 2x a-b 1.27 (0.050) bsc 7x 0.31 - 0.51 (0.012 - 0.020) 0.25 (0.010) m c a-b d 0.25 (0.010) 0.10 (0.004) (0.049 - 0.065) 1.25 - 1.65 1.75 (0.069) 1.35 (0.053) 0.10 (0.004) c 7x c h o 1.27 (0.050) 0.40 (0.016) gauge plane 0 - 8 1.04 (0.041) ref 0.25 (0.010) bsc sea ting plane 0.25 (0.010) 0.17 (0.007) det ai l a det ail a c sea ting plane pin 1 id b 4 + + + 4.90 (0.193) 1.27 (0.050) 0.60 (0.024) 2.00 (0.079) reference solder pad dimensions + part ordering information ? linkswitch product family ? ii series number ? package identifer d plastic so-8 ? package material g green: halogen free and rohs compliant ? tape & reel and other options blank standard confgurations tl tape & reel, 2.5 k pcs. lnk 632 d g - tl
for the latest updates, visit our website: www.powerint.com power integrations reserves the right to make changes to its products at any time to improve reliability or manufacturability. power integrations does not assume any liability arising from the use of any device or circuit described herein. power integrations makes no warranty herein and specifically disclaims all warranties including, without limitation, the implied warranties of merchantability, fitness for a particular purpose, and non-infringement of third party rights. patent information the products and applications illustrated herein (including transformer construction and circuits external to the products) may be covered by one or more u.s. and foreign patents, or potentially by pending u.s. and foreign patent applications assigned to power integrations. a complete list of power integrations patents may be found at www.powerint.com. power integrations grants its customers a license under certain patent rights as set forth at http://www.powerint.com/ip.htm. life support policy power integrations products are not authorized for use as critical components in life support devices or systems without the express written approval of the president of power integrations. as used herein: 1. a life support device or system is one which, (i) is intended for surgical implant into the body, or (ii) supports or sustains life, and (iii) whose failure to perform, when properly used in accordance with instructions for use, can be reasonably expected to result in signifcant injury or death to the user. 2. a critical component is any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness. the pi logo, topswitch, tinyswitch, linkswitch, dpa-switch, peakswitch, ecosmart, clampless, e-shield, filterfuse, stakfet, pi expert and pi facts are trademarks of power integrations, inc. other trademarks are property of their respective companies. ?2009, power integrations, inc. power integrations worldwide sales support locations world headquarters 5245 hellyer avenue san jose, ca 95138, usa. main: +1-408-414-9200 customer service: phone: +1-408-414-9665 fax: +1-408-414-9765 e-mail: usasales@powerint.com china (shanghai) room 1601/1610, tower 1 kerry everbright city no. 218 tianmu road west shanghai, p.r.c. 200070 phone: +86-21-6354-6323 fax: +86-21-6354-6325 e-mail: chinasales@powerint.com china (shenzhen) rm a, b & c 4th floor, block c, electronics science and technology bldg., 2070 shennan zhong rd, shenzhen, guangdong, china, 518031 phone: +86-755-8379-3243 fax: +86-755-8379-5828 e-mail: chinasales@powerint.com germany rueckertstrasse 3 d-80336, munich germany phone: +49-89-5527-3910 fax: +49-89-5527-3920 e-mail: eurosales@powerint.com india #1, 14th main road vasanthanagar bangalore-560052 india phone: +91-80-4113-8020 fax: +91-80-4113-8023 e-mail: indiasales@powerint.com italy via de amicis 2 20091 bresso mi italy phone: +39-028-928-6000 fax: +39-028-928-6009 e-mail: eurosales@powerint.com japan kosei dai-3 bldg. 2-12-11, shin-yokohama, kohoku-ku yokohama-shi kanagwan 222-0033 japan phone: +81-45-471-1021 fax: +81-45-471-3717 e-mail: japansales@powerint.com korea rm 602, 6fl korea city air terminal b/d, 159-6 samsung-dong, kangnam-gu, seoul, 135-728, korea phone: +82-2-2016-6610 fax: +82-2-2016-6630 e-mail: koreasales@powerint.com singapore 51 newton road #15-08/10 goldhill plaza singapore, 308900 phone: +65-6358-2160 fax: +65-6358-2015 e-mail: singaporesales@powerint.com taiwan 5f, no. 318, nei hu rd., sec. 1 nei hu dist. taipei, taiwan 114, r.o.c. phone: +886-2-2659-4570 fax: +886-2-2659-4550 e-mail: taiwansales@powerint.com europe hq 1st floor, st. jamess house east street, farnham surrey gu9 7tj united kingdom phone: +44 (0) 1252-730-141 fax: +44 (0) 1252-727-689 e-mail: eurosales@powerint.com applications hotline world wide +1-408-414-9660 applications fax world wide +1-408-414-9760 revision notes date a initial release 02/09 b introduced max current limit when v drain is below 400 v 07/09 c added clampless ? design note on page 3 09/09
|
