View MH2501SC_8999354.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

shindengen electric mfg.co.,ltd - 1 - MH2501SC/mh2511sc application note jul.2012 ver.1.0 easy multi interleave controller for multi-phase interleaved pfc application note ver.1.0 ? shindengen electric manufacturing co., ltd.
shindengen electric mfg.co.,ltd - 2 - thank you for purchasing this product. when using this ic, please follow the warnings and cautions given below to ensure safety. warning ! improper handling may result in death, serious injury, or major property damage. caution ! improper handling may result in minor injury or property damage. warning ! this ic is intended for use in general electronic machines, such as business equipment, communications equipment, measuring instruments, and household appliances. do not use this ic in medical devices, aerospace equipment, railway or other transport equipment (e.g., automobiles, ships), nuclear power control equipment, or any other equipment required to demonstrate mission- critical reliability or safety, or whose malfuncti on may directly cause injuries or endanger human life. contact us before using the product for any applications other than general electronic machines. caution ! ! ! ! ! never attempt to repair or modify the product. doing so may lead to serious accidents. <> in the event of a problem, an excessive voltage may arise at an output terminal, or the voltage may drop. anticipate these fluctuations and any consequential malfunctions or destruction and provide adequate protection for equipment, such as overvoltage or overcurrent protection. check the polarity of the input and output terminals. make sure they are properly connected before turning on power. <> use only the specified input voltage. deploy a protective element on the input line. <> in the event of a malfunction or other anomaly, shut power off and contact us immediately. ? the contents of this document are subject to change without notice. ? use of this product constitutes acceptance of the formal specifications. ? we have taken every possible measure to ensure the accuracy of the information in this document. however, we will not be held liable for any losses or damages incurred or infringements of patents or other rights resulting from use of this information. ? this document does not guarantee or license the execution of patent rights, intellectual property rights or any other rights of shindengen or third parties. ? no part of this document may be reproduced in any form without prior consent from shindengen. ! we strive at all times to improve the quality and reliability of our products. however, a certain risk of malfunctions is inevitable with semiconductor products. you are responsible for producing a design that meets safety requirements (whether a redundant design, a design that prevents the spread of fire, or designs that minimize the possibility of malfunctions) necessary to avoid injury, fire, or damage to social credibility that may result should any of our products malfunction. ! the semiconductor product described in this document is not designed or manufactured for use in a device or a system required to demonstrate mission-critical reliability or safety, or whose malfunction may directly cause injuries or endanger human life. contact us before using the product for any of the following special or specific applications: special applications transport equipment (e.g., automobiles and ships), communications equipment for a backbone network, traffic signal equipment, disaster or crime prevention equipment, medical devices, various types of safety equipment, and other applications specific applications nuclear power control systems, aircraft equipment, aerospace equipment, submarine repeaters, medical equipment used in life-support, and other applications ! even if the equipment is not designed for a special or specific application, please consult with us before using any of our ic products in equipment required to run continuously for extended periods. we provide support for circuit design to ensure safe use of our ic products. please contact one of our sales representatives or our product mark eting department if you have any questions. MH2501SC/mh2511sc precautions
shindengen electric mfg.co.,ltd - 3 - index 1 : outline 1.1: features 5 1.2: block diagram 5 1.3: pin arrangement diagram 6 1.4: pin function list 6 2 : operating principles for master ic and/ or slave ic 2.1 operating principles of current-critical pfc with on range control 7 2.2: zero current detection master 8 2.3: interleaving master slave 9-10 2.4: startup and shutdown sequences master slave 11 2.5: output voltage control master 12 2.6: phase compensation master 13 2.7: gate driver master slave 13 2.8: protection functions 2.8.1: overcurrent protection master slave 14 2.8.2: output overvoltage protection (ovp) master slave 14-15 2.8.3: low input voltage protection and fb pin open/short protection master 15 2.8.4: output diode short protection master 16 2.8.5: vcc pin undervoltage protection (uvlo) master slave 16 2.8.6: thermal shutdown master 16 2.9 application circuit 2.9.1: slave stop protection 17-18 2.9.2: remote on/off 18 2.9.3: switching the number of phases 19 2.10: example of operation waveforms 20 3 : circuit example 3.1: typical circuit diagram 21 4 : determining peripheral circuit constants 4.1: selecting choke coils 22 4.2: selecting the mosfet 23 4.3: selecting an output diode 23 4.4: selecting a bypass diode 23 4.5: adjusting constants for components around z/c pin 24 4.6: adjusting phase compensation 25 4.7: adjusting the output voltage 25 4.8: adjusting the overcurrent protection point 26 4.9: selecting the output capacitor 26
shindengen electric mfg.co.,ltd - 4 - 5 : precautions for protective functions 27 6 : precautions for pattern layouts 6.1 wiring for main current routes 28 6.2 gnd wiring 29 6.3 wiring of components around mosfet 30 6.4 wiring of ic peripheral components 30 6.5 pattern layout example 6.5.1: side a 31 6.5.2: side b 32 notes the figures in this document are provisional. for nomin al values, please refer to the formal specifications. function of master ic only function common to master ic and slave ic [indication of ic] master master slave
shindengen electric mfg.co.,ltd - 5 - 1 outline MH2501SC (?master ic? hereinafter) and mh2511sc (?slave ic? hereinafter) comprise ics for a current-critical interleaved pfc circuit. interleavin g with master and slave ics ensures low noise and high efficiency, which are characteristics of current-critical pfcs, even in high power regions. one-phase pfc can be configured using just the master ic. 1.1 features 1. high efficiency and low noise via master-slave interleaved critical current mode 2. two or greater phase interleaving achieved by connecting slave ics in parallel 3. one-phase pfc configurable using just the master ic 4. support for wide range of input voltage s with guaranteed vcc withstand voltage of 26 v 5. variety of protective functions (overvoltage protection, overcurrent protection, feedback open/short protection, and output diode short protection) 1.2 block diagram fig. 1 master ic (MH2501SC) block diagram out il_out ocl il_in latch timer vcc gnd 3 2 4 7 6 8 vcc_uvlo 1 5 phase shifter il_in edge out master_on timer 50us slave_stop2_f/f q qr s master_on counter_f/f q qr s master_on timer_f/f q qr s on/off_f/f q qr s slave_stop1_f/f q qr s vcc - + + - driver ocl timer fig. 2 slave ic (mh2511sc) block diagram
shindengen electric mfg.co.,ltd - 6 - 1.3 pin arrangement diagram package: sop8 fig. 3 pin arrangement diagrams for MH2501SC and mh2511sc 1.4 pin function list << master i c MH2501SC>> pin no. symbol function 1 fb input pin of feedback error amplifier 2 comp output pin of feedback error amplifier 3 il_out output pin for signal for interleaving connected to il_in pin of a slave ic 4 ocl input pin for overcurrent detection 5 z/c zero current detection pin of master ic 6 gnd gnd pin 7 out output pin for driving mosfet of master ic 8 vcc power supply voltage input pin << slave ic mh2511sc>> pin no. symbol function 1 il_in input pin for signal for interleaving connected to il_out pin of the master ic or previous?phase slave ic 2 il_out output pin for signal for interleaving connected to il_in of the next slave ic 3 latch output pin for latching stops the operation of the master ic in case of problems with a slave 4 ocl input pin for overcurrent detection 5 timer timer capacitor connection pin for de tection in one-phase configuration detects whether a slave ic is operating 6 gnd gnd pin 7 out output pin for driving mosfet of slave ic 8 vcc power supply voltage input pin
shindengen electric mfg.co.,ltd - 7 - 2 operating principles 2.1 operating principles of current-critical pfc with on range control fig. 4 critical operation fig. 5 waveform of a single switching cycle this ic employs a current-critical system. as shown in fig. 4, the choke current il forms triangle waves, starting and ending at 0 a repeatedly. the ic also uses an on range control system. the on range t on is determined by the load and is fixed. the off range t off varies with the input voltage v in at every switching. the switching period varies. the following formulas give the currents: t on and l are fixed. the peak value of il , il(peak), is proportional to v in . since v in is sinusoidal, il(peak) is sinusoidal. (formula 1) ]a[ )( l tv peakil onin ? ? ...(1) the switching frequency is significantly hi gher than the ac commercial frequency. v in is considered constant during a single switching cycle (fig. 5). the input current i in equals il(ave), which is il with its high frequency component removed by the capacitor c in and averaged. since il is a triangle wave, il(ave) is half of il(peak). (formula 2) ]a[ 2 )( )( peakil aveili in ?? ...(2) we substitute formula 1 into formula 2. ]a[ 22 )( )( l tv peakil aveili onin in ? ? ?? ...(3) as formula 3 shows, i in is proportional to v in due to the on range control of this ic. the power factor is improved. fig. 6 shows waveform examples on the circuit. fig. 6 waveform examples on the circuit
shindengen electric mfg.co.,ltd - 8 - 2.2 zero current detection master this ic detects the control coil voltage to turn on the switching device. the z/c pin determines turn-on timing. as shown in fig. 7, the main switch activates when the z/c pin voltage drops below the zero detection voltage (0.5 v). the main switch is turned on after every switching cycle once the energy of the choke coil is fully discharged (i.e., a current-critical operation is performed). hysteresis of +1 v is added to the zero detect ion voltage to increase noise resistance. unless a voltage exceeding +1.5 v is applied to the z/c pin, the switch operates in the restart cycle (150 s). this ic incorporates an on-dead timer. this function disables the on-trigger for a period (tondead) after the gate-off signal is turned on, thereby preventing unintended operations due to ringing generated at gate-off. a ringing voltage may be generated at gate-off, resulting in detection of the on-trigger and turning on the switch before the current critical point. see section 4.5 for constants for the components around the z/c pin. z/c pin voltage 0.5v hysteresis 1v zero detection voltage 0v diode current main switch vds 0v 0a 0a main switch idid tondead fig. 7 turn-on timing (z/c pin)
shindengen electric mfg.co.,ltd - 9 - 2.3 interleaving master slave multi-phase interleaved critical conduction mode pf c is configured by connecting the master ic and several slave ics. * master ic pin names are identified by an appended ?m?; slave ic pin names are identified by an appended ?s? and a unique slave identification number at the end. the il_out(m) pin of the master ic is a signal out put pin that activates interleaving by a slave ic. the il_out(m) pin is connected to the il_in(s1) pin of the slave ic. as shown in fig. 8, for multi-phase interleaving of three or more phases, the il_out(s1) pin is connected to the il_in(s2) pin of the next slave ic. to reduce noise, insert a resistor and a capacitor near the il_in pin. we recommend a 1 k ? resistor and a 47 pf capacitor. fig. 8 example of interleaved connection this section discusses turn-on timing and transm ission of the on range in an interleaved circuit. fig. 9 shows the operating sequence. the arrows in fig. 9 indicate the transmission order of on range. see fig. 9 for waveform and arrow numbers referenced in the text below. 1) the out (m) of the master ic outputs a hi signal determined by the negative edge of the z/c pin and the comp pin voltage. 2) the il_out(m) signal of the master ic is output in sync with the out(m) (waveform c and arrow 1). 3) the il_out(m) signal of the master ic is input to the il_in(s1) pin of the slave ic via cr as shown in fig. 8 (waveforms c and d and arrow 2). in the slave ic (1), the counter circui t stores the on range of the il_in(s1). 4) the out(s1) of the slave ic (1) is turn ed on when the master ic is turned off to output the stored on range. the on range is the same as that of the out(m) (waveform e and arrow 3). 5) the il_out(s1) signal of the slave ic (1) is output in sync with the out(s1) (waveform f and arrow 4). 6) to achieve multi-phase interleaving, conne ct the il_out(s1) pin to the il_in(s2) pin of the next slave ic (2) (waveform f and arrow 5).
shindengen electric mfg.co.,ltd - 10 - out(m) pin (waveform b) master main sw d-s voltage choke current waveform il_out(m) pin (waveform c) il_in(s1) pin (waveform d) out(s1) pin (waveform e) slave (1) main sw d-s voltage choke current waveform il_out(s1) pin (waveform f) z/c pin (waveform a) master ic slave ic (1) 0v 0a 0v 0v 0v 0v 0v 0v 0a 0v vcc 5v 5v vcc 5v to the il_in(s2) pin of the next slave ic (2) (1) (2) (3) (4) (5) fig. 9 interleaved operating sequence
shindengen electric mfg.co.,ltd - 11 - 2.4 startup and shutdown sequences master slave fig. 10 shows the startup and shutdown sequence s for interleaved operation. vcc is common to the master ic and slave ic. acin vo vcc comp out(m) out(s) ovp operation vcc(start)s vcc(start)m vcc(stop)s vcc(stop)m 1.2v fb vo_ref1.08v 0.4v 0v 0v 0v 0v 0v 0v 0v vo_ref fig. 10 startup and shutdown sequences (a) oscillation start sequence (1) when a voltage is applied to the vcc pin, the comp is charged to 1.2 v. (2) when the vcc voltage reaches vcc(start)s, the slave ic starts up. however, the gate signal is not output, since t he master ic has not started up. (3) when the vcc voltage reaches vcc(start)m, the master ic also starts up and starts the gate output. the slave ic also starts gate output. (4) immediately after startup, gate output st ops due to the ovp operation, suppressing an increase in output voltage. (b) oscillation stop sequence (1) when the vcc voltage has fallen to vcc( stop)m, the master ic shuts down and stops the gate output. the slave ic also stops the gate output. the comp voltage is clamped to 1.2 v. (2) when the vcc voltage has fallen to v cc(stop)s, the slave ic shuts down.
shindengen electric mfg.co.,ltd - 12 - 2.5 output voltage control master this ic detects the output voltage and changes the on range of the main switch to control the output voltage. as shown in fig. 11, the output voltage is di vided using the resistors r191 to 195 and r196 and the fraction of the voltage is applied to the fb pin. this stabilizes the output voltage relative to which the fb pin voltage is 2.5 v. the comp pin voltage, the output of a feedback error amplifier, is proportional to the on range of the main switch. the switch is activated when the voltage is 1.2 v or greater. the on range reaches the maximum when the voltage is 4.0 v (f ig. 12). this feedback controls the comp pin voltage and stabilizes the output voltage. connect a capacitor (c191) near the fb and gnd pins to reduce noise. a capacitor with excessive capacity may affect response. we recomm end 1000 pf to 2200 pf. comp fb 2.5v= fb_ref 2 pfc out r191 ~ r195 r196 c191 1 6 gnd fig. 11 fb pin internal block diagram v comp vs on time 0 5 10 15 20 25 30 0.0 1.0 2.0 3.0 4.0 5.0 v comp [v] fig. 12 relationship between comp pin voltage and on range
shindengen electric mfg.co.,ltd - 13 - 2.6 phase compensation master the pfc converter must be adjusted so that it does not respond to commercial ac input frequencies. capacitors (c113 and c114) and a resistor (r 117) are connected between the comp pin and gnd pin of the master ic to correct the phase of the amplifier and reduce the feedback loop gain at commercial ac input frequencies. fig. 13 shows an example circuit. we recommend a c114 of about 2.2 uf, c113 of 0.22 uf, and r117 of 1 k ? . see section 4.6 for information on adjusting the comp pin. fig. 13 comp pin connection example 2.7 gate driver master slave the signal output from the out pin determines the turn-on and turn-off timings for each switch. the out pin receives a supply from the power supply voltage vcc. the gate driver capacity is 0.5 a (source) and 1.2 a (sink). fig. 14 shows examples of commonly used driver circuits. when a discharging diode (d112) is used as sh own in examples a and b, use a small-capacity schottky diode or other such diode. do not use a snappy (hard) recovery diode. we recommend d1ns4 (axial) or m1fm3 (surface mounting). if the qg of mosfet (q111) is large and when fu ll discharge is not possible, add a pnp transistor (q112) on the discharge side as shown in the example c), fig. 14. fig. 14 gate driver circuit
shindengen electric mfg.co.,ltd - 14 - 2.8 protection functions 2.8.1 overcurrent protection master slave for overcurrent protection, the ocl pin monitors a voltage determined by the overcurrent detection resistor (r111), which is connected between the source and gnd of the mosfet, as shown in fig. 15. the main switch turns off when the ocl pin volt age rises to 0.5 v or greater. set the overcurrent detection point above the maximum drain curren t during normal operations and lower than the choke saturation current. this ic has the leading edge blank timer (tleb). the overcurrent detection is not accepted for a certain period after the gate-on signal has been turned on to prevent unintended activation of overcurrent protection due to noise generated immediately after gate-on (see fig. 16). to prevent unintended operations due to switching noise, insert a capacitor (c116) as shown in fig. 15. place the capacitor near the ocl and gnd pins. we recommend a capacitor of about 1000 pf. you can also add a r118 to further reduce unintended operations due to noise. the resistance should be 100 ? to 1 k ? . see section 4.8 for ocl pin design procedure. +0.5v ocl pin main switch id tleb 4 6 r118 ocl gnd q111 r111 c116 7 out out pin fig. 15 ocl pin connection example fig. 16 overcurrent protection operating sequence 2.8.2 output overvoltage protection (ovp) master slave for output overvoltage protection (ovp), when the fb pin voltage rises to 2.7 v (fb_ref x 1.08) or greater as shown in fig. 17, the gate outputs of the master ic and slave ic are stopped to suppress increases in output voltage. this reduces t he stress on electrolytic capacitors and other components. a pfc circuit is generally designed to respond slowly to prevent response to commercial frequencies. the output voltage may rise temporarily in a transit ional state, such as startup and a dramatic change in load. this function provides effective protection against such increases. fig. 18 shows the sequence of ovp operations . during ovp operations, the il_out of the master ic is forced to output a pulse for a fixed time of 80 s. if the il_in pin of the slave ic receives a pulse exceeding 50 s, no out signal are output. the slave ic will stop safely. protection function fb pin threshold gate output other state output overvoltage protection (ovp) 2.7 v or greater (fb_ref x 1.08 v) off output voltage setting x 1.08 or greater the master ic outputs a slave stop signal.
shindengen electric mfg.co.,ltd - 15 - fig. 17 fb pin internal block diagram il_out(m) pfc out vo_ovp out(m) out(s) 80usec no gate output 0v 0v 0v 0v fig. 18 ovp operating sequence 2.8.3 low input voltage protection and fb pin open/short protection master the low input voltage protection halts the gate out put when the input voltage falls and the fb pin voltage falls to 0.4 v or less. this reduces stress on the mosfet and other components. when the fb pin is opened or when the fb pin is short-circuited with the gnd, the fb pin voltage drops to 0.4 v or less. this function halts gate output. protection function fb pin threshold gate output other state low input voltage protection fb pin open/short protection 0.4 v or less off colm pin voltage = 1.2 v
shindengen electric mfg.co.,ltd - 16 - 2.8.4 output diode short protection master a short-circuited output diode results in the detec tion of an overcurrent, and the internal counter of the master ic begins counting. once the counter counts to 512, the ic is latched and stopped. this function prevents the ic from continuing to operate with the diode short-circuited. for unlatching, the vcc voltage needs to be discharged and then input again. the internal counter is reset when the z/c pin reac hes 4 v or more to disable the function at startup or in the event of an overload. fig. 19 shows the sequence of steps involved in the output diode short protection feature of a master ic. when the output diode of a slave ic is short-ci rcuited, the ic is latched and stopped in a similar sequence. fig. 19 operating sequence in output diode short protection 2.8.5 vcc pin undervoltage protection (uvlo) master slave to turn vcc on and off safely, the oscillation star t/stop voltages differ between the master ic and the slave ic. when a voltage is applied to the vcc pin, the slave ic is activated first to ensure that the slave ic will be stable when the master ic is activated. when the voltage supply to vcc is stopped, the master ic stops first to ensure that all the ics stop safely. the table below shows the absolute maximum rati ng and oscillation start and stop voltages of the vcc pin. voltage between vcc & gnd master ic MH2501SC slave ic mh2511sc absolute maximum rating 26 v (common to master and slave) oscillation start voltage 11 v 9.5 v (starts earlier) oscillation stop voltage 9 v (stops earlier) 7.5 v 2.8.6 thermal shutdown master oscillation stops if the master ic generates ex cessive heat for any reason and when the ic junction temperature exceeds the operation stop temperatur e (tsd) of 130c. if the ic junction temperature falls to about 70c, oscillation resumes automatically.
shindengen electric mfg.co.,ltd - 17 - 2.9 application circuit 2.9.1 slave stop protection master slave the timer and latch pins of the slave ic and t he comp pin of the master ic can be used to keep the master ic from operating independently while the slave ic is not working due to an external problem. for example, if the in terleaving signal wire is disconnected. fig. 20 shows an example of a 3-phase connection circuit. fig. 21 shows the circuit operating sequence. as shown in fig. 20, the control coil of eac h choke coil is connected to the timer and latch pins of the slave ic and the comp pin of the master ic. see fig. 20 for the structure and polarity of each choke coil. during normal operations, the timer pin voltage is kept near 0 v by charging and discharging each control coil. the latch pin is in a low impedance state (gnd level). if a slave ic fails to function due to a probl em, the timer pin voltage increases. when the voltage reaches 2.5 v, the latch pin enters and remains in a high impedance state (open collector). this activates the transistor connected between the comp and gnd pins of the master ic and halts the os cillation of the master ic. the latch pin is unlatched when vcc is reduced to 7.5 v or less. if you do not intend to use this function, short-circuit t he timer pin and the gnd. during certain periods, only the master ic operates while the slave ic does not?for instance, when the output overvoltage protection (ovp) is on at startup. in this case, the timer pin is discharged by the switch in the slave ic to 0 v. as soon as the ovp is released, the slav e ic stops discharging the timer pin. see section 2.8.2 for more information on output overvoltage protection (ovp). ` master ic slave ic (1) slave ic (2) comp vcc latch (s1) timer (s1) vcc latch (s2) timer (s2) 1000p 22k 22k 56k 56k 56k 1u 1u 56k 1k fig. 20 examples of circuit configurations that protect against problems with the slave
shindengen electric mfg.co.,ltd - 18 - fig. 21 operating sequence of protection circuit intended to protect against problems with the slave (interleave signal disconnection) 2.9.2 remote on/off master the master ic can be turned off by remote control by either method (1) or (2) below. to cancel the remote-off, release the state (1) or (2). (1) short-circuit comp and gnd. (2) reduce vcc to uvlo or less. during interleaved operation, the slave ic is automatically stopped by stopping the master ic by one of the above methods.
shindengen electric mfg.co.,ltd - 19 - 2.9.3 switching the number of phases to turn off just the slave ic only, use a trans istor or similar component to short-circuit the il_in pin of the slave ic and gnd pin, as shown in fig. 22. blocking the interleaving signal turns off the slave ics onwards. an external signal changes the number of phases. r127 and r137 are current limiting resistors for the il_out pin. when also using slave stop protection as described in section 2.9.1 , be sure to short- circuit the gnd and the timer pin of the slav e ic you want to stop by blocking the interleaving signal before blocking the interleav ing signal. for example, to stop the slave ics from the ic (1) onwards, short-circuit c125 first, then turn on q123 (see arrow (1) in fig. 22). perform a similar procedure (see arrow (2) in fig. 22) to stop from the slave ic (2) onwards. slave ic(2) il_out 2 r127 c123 1 6 gnd il_in il_out 2 r137 c133 1 6 gnd il_in il_out 3 master ic slave ic(1) switch to one phase switch to two phases 5 timer c125 5 timer c135 q123 q133 short-circuit short- circuit (1) (1) (2) (2) fig. 22 switching the number of phases
shindengen electric mfg.co.,ltd - 20 - 2.10 example of operation waveforms operation waveforms of the typical circuit diagr am (input: 180 to 264 vac, output voltage: 390 v, output capacity: 4 kw and 3-phase interleaved configuration) as shown in section 3.1 input voltage: 200 vac output power: 500 w (vo = 320 v) input voltage: 200 vac output power: 4 kw (vo = 320 v) input voltage: 200 vac output power: 4 kw (vo = 320 v) waveform 1: critical operation by zero current ch1 vds(m) 100v/div ch2 id(m) 1a/div ch3 v comp 2v/div ch4 v z/c 5v/div time 400ns/div waveform 2: main switch current (3-phase interleaving) ch1 vds(m) 100v/div ch2 id(m) 2a/div ch3 id(s1) 2a/div ch4 id(s2) 2a/div time 10us/div waveform 3: input voltage and current ch1 vin(ac) 250v/div ch2 iin(ac) 20a/div time 10ms/div resonance period ch1 ch3 ch4 ch2 ch1 ch3 ch2 ch4 ch1 ch2
shindengen electric mfg.co.,ltd - 21 - 3 circuit example 3.1 typical circuit diagram (input: 180 to 264 vac, output voltage: 390 v, output capacity : 4 kw and 3-phase interleaved configuration) vo=390v gnd ic111 ic121 vcc c109 680u*2para l101 c101 c104 c113 0.47u c191 2200p c111 100p c121 100p c112 150u c122 150u c132 150u r111 0.047 2para r112 10k r110 12k r122 10k r118 1k r117 1k r191 180k r192 510k r193 910k r194 910k r196 22k r195 910k gnd q111 f35w60c3 q121 f35w60c3 l111 60uh l121 60uh d111 sf20k60m d121 sf20k60m d131 sf20k60m d101 ll25xb60*2 c103 c102 c106 c105 f101 30a d141 d4f60 c114 2.2u r128 1k c116 1000p c124 1000p c134 1000p c123 47p r137 1k r115 4.7 r124 47 r121 0.047 2para r127 1k c108 2.2u*3para d113 m1fs4 r125 4.7 d123 m1fs4 c136 47p 1 2 4 5 6 7 8 1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8 3 l131 60uh MH2501SC mh2511sc po=4kw ac180v264v r114 47 c131 100p r132 10k r138 1k r134 47 r131 0.047 2para r135 4.7 d133 m1fs4 q131 f35w60c3 ic131 mh2511sc q112 q122 q132
shindengen electric mfg.co.,ltd - 22 - 4 determining peripheral circuit constants the characteristics of a pfc circuit also depend largely on peripheral components besides ic. for optimum design, clarify the specificati ons for the required power supply and select components as described below. 4.1 selecting choke coils (l111, l121, l131?) choke coils are important components that can determine the performance of a pfc circuit. work out the ideal constants for pfc ci rcuit specifications using the formulas below. inquire with coil manufacturers, if necessary. check for rising core and coil temperatures in an actual device before finalizing coil and core sizes. select the core size to make sure that core gap ig does not exceed 2 mm. use formulas (1) to (5) below to calculate the core gap ig. ]mm[10 lp 4lg 7- 2 ? ? ?? npae ? ... (1) ]mh[10 idp 2min)( 3 ? ? ?? acvin tonlp ... (2) ]a[ vin(ac)min 22 ? ?? ? ? ps idp ... (3) ][ min max s f don tdonton ??? ... (4) vo acvinvo don 2min)( ? ? ? ... (5) ae represents the effective cross sectional area [mm 2 ] of the core, ps the output power [w] (1.2 to 1.5 times as high as po(max)) at the droop point, and fmin the minimum oscillation frequency [hz] (auto-sensing power supply: 40 k to 60 khz, 100 v/ 200 v group: 50 k to 70 khz). the figures in parentheses are provided as guidelines only. the result given by formula (6), rounded down to t he nearest integer, gives the number of turns of the np choke coil. ][10 aeb 2min)( 9 turn acvin tonnp ? ? ? ?? ... (6) ? b represents the magnetic flux density variation [mt] of the core. ? b can vary significantly from core to core. inquire with the coil manufacturer. apply formula (7) to select the minimum integer fo r the number of turns of the nc coil. a minimum voltage of 1.5 v should be generated in the control coil at maximum input voltage. ][ max})(2{ 5.1 turn acvin vo np nc ?? ?? ... (7) in the case of an auto-sensing power supply, as suming that vin(ac)max is 264 v and that pfc output voltage vo is 390 v, a ratio of the numbers of turns of np and nc is approximately 10 to 1. example) the number of turns of np wi th an auto-sensing power supply is 50. assuming that vin(ac)max = 264 v and vo = 390 v, nc > 4.5 and nc = 5 turns.
shindengen electric mfg.co.,ltd - 23 - select the cross-sectional area of the np coil ba sed on the effective current il(rms) [a] and the current density of the choke coil [a/mm 2 ]. note that current density will vary with the type of copper wire (single wire or litz wire), number of strands, and other factor s. fig. 23 shows il(rms) at an input of 85 vac. refer to the chart when inquiring with the coil manufacturer. il(rms) v.s. po ac85v 0 1 2 3 4 5 6 50 100 150 200 250 300 350 400 po[w] il(rms)[a] fig. 23 il(rms) at an input of 85 vac 4.2 selecting the mosfet (q111, q121, q131?) select a mosfet with a current rating higher than the maximum drain current idp multiplied by the margin. check the junction temperature on the actual devic e before final selection of a mosfet and heat sink. use the following as a guide to margins for the product current rating and product withstand voltage. ]v[25.1 voltage thstand product wi vo ... (8) ][25.1 rating current product a idp ... (9) vo is the set output voltage. 4.3 selecting an output diode (d111, d121, d131?) select a diode with a current rating 6 to 8 times the maximum load current lo_max., using the value as a guideline. for an interleaved circuit, divide lo_max by the number of phases to obtain current per phase. check the junction temperature on the actual device before final selection of a diode and heat sink. 4.4 selecting a bypass diode (d141) select a bypass diode (d141) with a peak surge forward current ifsm greater than the maximum inrush current. the maximum inrush current varies with pattern impedance and input voltage. simulate to check the current, or measure with the actual device. example of recommended component: d4f60 (shindengen)
shindengen electric mfg.co.,ltd - 24 - 4.5 adjusting constants for components around z/c pin you can adjust the turn-on timing by adding a capa citor c115 between the resistor r110, the z/c pin, and gnd (fig. 24). adjust the timing so t hat the switch activates when the drain-source voltage (vds) reaches the lower limit in the resonance period (see waveform 1 in section 2.10 ). this will help reduce switching losses. the c115 should be around 15 pf. adjust the r110 while referring to formulas (10) and (11) below and monitoring vds at the maximu m input voltage on the actual device. the maximum current flowing into and out of the z/c pin, which determines the turn-on timing, is 5 ma. the resistor r110 needs to be adjusted to ensure that the current flowing to the z/c pin does not exceed 80% of the maximum current. specifically, select a resistance greater than rzc, the resistance given by formulas (10) and (11). fig. 24 circuit around z/c pin for instance, assume vo = 400 v, vin(ac)max = 276 v, np = 50 turns, and nc = 5 turns. ? positive side of control coil : ][4.8 104 5.6 50 5 400 3 ? ? ? ? ? ? ? ? ? ? ?? ? ? negative side of control coil : ? ? ][8.9 104 50 5 2276 3 ? ? ? ? ? ? ? ? ? ? ??? ?? ? set the z/c control resistor r110 to 9.8 k ? or more. ? positive side of control coil ][ 104 5.6 3 ? ? ? ? ? ? ? ? ? ? ? ? ?? g?g?g? (10) * 6.5 v is the zener voltage in the z/c pin. ? negative side of control coil ? ? ][ 104 2max)( 3 ? ? ? ? ? ? ? ? ? ? ? ?? ? ?? (11) z/c 5 np r110 c115 l111 nc
shindengen electric mfg.co.,ltd - 25 - 4.6 adjusting phase compensation (r117, c113, and c114) a transconductance amplifier (gm amplifier) is used as the error amplifier for the master ic. to adjust the phase compensation circuit, connect the capacitors and the resistor while referring to fig. 25. formula (12) gives the capacitance of c114. the cutoff frequency fc should be about 20 hz. the capacitance of c113 should be about a tenth that of c114. ][ 2 140 114 f fc c ? ? P ? ... (12) * amplifier transconductance:140 [ a / v] increasing the resistance of r117 lets you adjust the gain in a high frequency region above the cutoff frequency fc. if the resistance is too high, the waveform may be distorted. set to between 1 k ? and 10 k ?. * recommended constants: r117=1k ? , c113=0.22 f, c114=2.2 f adjustments of the phase compensation circui t should vary with the constants of other components. use the calculation method gi ven above as a rough guide. check the operating waveform, power factor, and other factors on the actual device for final adjustments. 4.7 adjusting the output voltage (r191 to r196) use external voltage dividing resistors to set t he desired output voltage. connect resistors r191 to r196 to set the output voltage. (see fig. 26.) the error amplifier input threshold is 2.5 v. apply formula (13) to determine voltage dividing resistances. to reduce losses, we recommend targeting a total resistance for the upper voltage dividing resistors (r191 to r195) of about 2 m ? when the pfc output voltage is about 400 v. to prevent unintended noise-induced operations, insert a capacitor c191 between the fb and gnd pins. since this capacitor can affect feedback response, we recommend a capacitance of about 1000 pf to 2200 pf. fig. 26 circuit around fb pin ][ 5.2 )5.2(196 )195194193192191( ? ? ? ????? vor rrrrr ... (13) note that the precision of each resistance will di rectly affect the precisi on of the output voltage. we recommend using high-precision resistors. 2 fig. 25 circuit around comp pin
shindengen electric mfg.co.,ltd - 26 - 4.8 adjusting the overcurrent protection point (r111, r121, r131?) use overcurrent detection resistor r111 (and r121 and r131) to adjust the overcurrent protection point ps. apply formula (14) to determine the resistance of r111 (and r121 and r131). ps should be about 1.2 to 1.5 times the maximum load power pomax. when increasing the overcurrent protection point, carefully consid er the magnetic saturation of the choke coil. n ps vin(ac) vrrr ocl ? ?? ? ?? 22 min )131,121(111 [ ? ] ... (14) vocl is the overcurrent protection voltage of 0.5 v. n is the number of interleaved phases. 4.9 selecting the output capacitor (c109) the overvoltage detection voltage ( section 2.8.2 ) is set to 1.08 times the output voltage. determine the withstand voltage of output c apacitor c109, accounting for the overvoltage detection voltage plus a margin. ][08.1)( v voovpvo ?? ... (15) adjust the capacitance of the c109 accord ing to the output capacity and hold time.
shindengen electric mfg.co.,ltd - 27 - 5 precautions for protective functions the protective functions built into the master ic and slave ic will not work if the ic fails to function properly due to an anomaly. in case of ic malfun ctions, to prevent smoke and fire, the ic must be protected with an external protection element or circuit. some precautions related to protective functions are given below. the master ic incorporates a thermal shutdown fu nction. due to transient thermal resistance, the function may not be able to track temperatures adequately in cases of extreme temperature change resulting from a certain anomaly. the function detects the temperature of the ic onl y. this means the protection will not work even if the temperatures of external power devices (e.g., mosfets and diodes) rise. for extra safety, establish separate temperature detection and protection features for power devices. the slave ic lacks a thermal shutdown function. if only the slave ic will generate heat in the event of an anomaly, insert an overcurrent protection element in the vcc supply line. the master ic incorporates an overvoltage prot ection function. in cases of extreme voltage increases resulting from certain anomalies, the f unction may not work. for an additional margin of safety, use an external protection circuit to detect the output voltage on a different line from the fb line and to stop the master ic. see section 2.9.2 remote on/off for procedures for turning off the master ic. fig. 27 shows an example of an exte rnal overvoltage protection circuit. fig. 27 external overvoltage protection circuit the master ic incorporates a diode short protec tion function. if the output diode short-circuits due to a certain anomaly, this function shuts down t he master ic to protect the ic and the mosfet from secondary damage. with certain ocl settings or allowable loss of external mosfet, the ic or the mosfet may be damaged before the protection activates. to reduce this risk, review the ocl setting or your mosfet selection or take alternative measures (e.g., using a fuse or other element to ensure the ic stops safely even if damaged). note that various factors may keep the slave stop protection from functioning properly, including chattering noise in the il_in pin caused by a s hort circuit between the i l_in pin and another pin, or other anomalies. increase the filter constant to protect the il_in pin against noise in case of an anomaly. for extra safety, add temperature detection or ot her functions to the power devices.
shindengen electric mfg.co.,ltd - 28 - 6 precautions for pattern layouts pcb pattern design can significantly affect po wer supply characteristics. since the MH2501SC and the mh2511sc switch high voltage and current, great care is required when laying out patterns. to minimize noise attributable to the inductance component of the patterns, make the patterns of the main circuit as thick and as short as possible. design the patterns for controls to minimize electromagnetic interference. the precau tions for the main items are summarized below. always check to confirm that the ic func tions properly after designing the patterns. 6.1 wiring for main current routes there are two high current switching lines: one from the positive side of the input capacitor via the main choke and the main switch back to the input capacitor gnd (violet -> red -> violet in fig. 28); the other from the mosfet drain via the di ode and the output capacitor back to the input capacitor gnd (blue -> violet in fig. 28). make these two patterns as thick and as short as possible. circuit diagram 6 6 r111 r121 c111 c121 c109-1 c107-1 c109-2 c107-2 di c107-1 c107-2 l121 l111 d111 d121 c111 q111 q121 r111-1 r111-2 r121-1 r121-2 c109-1 c109-2 c109-3 c121 r111-1 r111-2 r121-1 r121-2 fig. 28 ideal wiring for main current routes
shindengen electric mfg.co.,ltd - 29 - 6.2 gnd wiring ground wiring can significantly affect the st ability of power supply operations. when a high current is switched, if the gnd is affected, so is the ic control. separate the gnd line from the high current switching lines as described in section 6.1 . specifically, note t he following aspects: (1) do not use a common gnd line. connect each ic current detection resistor to the input capacitor with separate gnd lines. (2) connect the gnd of each ic to the gnd of each current detection resistor at a single point. (3) do not route the gnd between ics should via the high current switching gnd lines (the red and blue lines in the diagram below). make the line as short as possible. (4) connect the gnd of the resonating capacit or to the gnd of the current detection resistor by the shortest possible distance. * see (1) to (4) in fig. 29. comply with the above precautions for gnd wiring. the next page shows examples of gnd wiring that comply with these precautions. use them as a guide in pattern layouts. 1 8 1 8 c107- 1 c107-2 l121 l111 ic111 c111 c121 r 111 - 2 r121-1 r121-2 c109-1 c109-2 c109-3 ic121 c122 c122 fig. 29 design example of gnd patterns ? .. (1) ? .. (2) ? .. (3) ? .. (4) ? .. other gnd patterns pale color: side a dark color: side b
shindengen electric mfg.co.,ltd - 30 - 6.3 wiring of components around mosfet parasitic oscillation may result if the wiring of the mosfet gate loop is too long or too close to a noise source. keep the following in mind when wiring the gate loop: ? make the wiring from the out pin of the master or slave ic to the mosfet gate as short as possible. ? position the wiring between the out pin and the gate at an adequate distance from magnetic components, such as choke coils. ? place the mosfet as close as possible to t he resonating capacitor. connect the gnd of the resonating capacitor to the gnd of the current detection resistor. ? use a resistor with a low inductance component as a detection resistor. di di 1 8 s d g fig. 30 design example of patterns around the mosfet 6.4 wiring of ic peripheral components place the ic peripheral components as close as possible to the ic pins. the components used to stabilize control include a backup capacitor connected to the vcc pin, a phase compensation component connected to the comp pin, and an output voltage detection component connected to the fb pin. connect each component to the gnd pi n of the ic at a single point, if possible. (see the wiring in pink.) fig. 31 design example of ic peripheral patterns 1 8 vcc backup ca p acito r output voltage detection component phase compensation component connect the gnd pattern of the ic to pin 6 by the shortest p ossible distance.
shindengen electric mfg.co.,ltd - 31 - 6.5 pattern layout example 6.5.1 side a c107-1 c107-2 c107-3 l131 l121 l111 d111 d121 d131 c111 q111 c121 q121 r111-1 r111-2 c112 c131 q131 r121-1 r121-2 c122 r131-1 r131-2 c132 c109-1 c109-2 c109-3 c109-4
shindengen electric mfg.co.,ltd - 32 - 6.5.2 side b di di di di di di di 1 8 1 8 1 8
shindengen electric mfg.co.,ltd - 33 - MH2501SC/mh2511sc application note ver. 1.0 created by: development department ii, electronic device division issued on july 25, 2012 shindengen electric mfg. co. , ltd

▲Up To Search▲

Price & Availability of MH2501SC

	To Download MH2501SC Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .