Bellnix Power IC BIC1422 <Summary> BIC 1422 is a high efficiency POWER-IC of MCM (multi chip module) with synchrounous rectification system chopper control, N channel MOSFET of main switch and low side MOSFET for synchronous rectification. Maximum output is 3A and the input voltage range is 8V-40V. The functions such as over-current protection, over-heat protection and ON/OFF control etc. are all put in the surface mount one-package IC, which makes it possible to achieve a small size and light DC-DC converter with very few external components. < Features > - Input voltage range: DC8-40V - Output voltage: Output voltage adjustable using external resistances (2.5V-12V) - Maximum output current: 3A (Derating is required for output higher than 8V) - Main switch MOSFET and commutation MOSFET - Overcurrent protection - Heat protection - Remote ON/ OFF control - Lead-free correspondence < Applications > - Information distribution equipment - Telecommunications equipment - Office automation equipment - Factory automation equipment (Process control) - Electronic measuring instruments - Audio-Video devices - Home appliances < Designation of product > Model name: BIC1422 For packaging, only tape and reel is available. Synchronous Main switch LOW Side Rectification MOS-FET MOS-FET control IC MCMIC vey + ger], + fgrmic) = | Bictgza TIT Input Output 8-40V 2.5V-12V mw v a CONTROL A HEHE HE O O This figure is different from actual wiring. 1 Belilnix DC-DC CONVERTERS BDD20050412-050704Bellnix <Absolute maximum rating (Ta=25C )> Item Symbol Rating Unit Line voltage Vin 42 Vv Output MOS input voltage Vdd 42 V Output current (AVE) lout ave 3 A Output current (PEAK) lout peak 4 A OCL-, OCL+ terminal voltage Voc. 5.5 V Remote control voltage VrRe 5.5 Vv Storage temperature Tstg -40 to 150 c Junction temperature Tj 150 C <Electrical charateristics (Ta=25C )> Item Symbol Conditions MIN TYP MAX Unit HighsideMOS Drain-source breakdown voltage Vdss Id=1mA,Vgs=0V 42 = = V HighsideMOs Vds=40V,Vgs=0V Drain interruption current Idss _ _ 10 pA HighsideMOs Id=1.2A, Vgs=4.5V Drain-source ON resistance Ron = 33 70 mQ HighsideMOs Is=1.2A,Vgs=0V Source-drain Di forward voltage Vsd _ _ 1.5 Vv . LowSideMOS ld=1mA,Vgs=0V Drain-source breakdown voltage Vdss 42 = _ Vv _ LowSideMOs Vds=40V,Vgs=0V Drain interruption current Idss = 10 pA __ LowSideMOs Id=1.2A, Vgs=4.5V Drain-source ON resistance Ron - 33 70 mi LowSideMOs Is=1.2A,Vgs=0V Source-drain breakdown voltge Vsd = = 1.5 V Start voltage Vec_start = 6.5 7.2 7.9 Vv Stop voltage Vec_stop - 6 6.7 7.4 Vv Start-stop voltage hysteresis Vec_hys - = 0.5 = V Current consumption Icc Vec=8V-40V _ 10 13 mA Current consumption with remote control OFFI Icc_off Vec=8V-40V 1.2 1.5 mA Voltage with remote control terminal ON Vre_on Vec=8V-40V -0.2 - 0.5 Vv Voltage with remote control terminal OFF Vrc_off Vec=8V-40V 2.5 - 5.3 Current with remote control terminals shorted Irc Vec=8V-40V - 250 HA Boot terminal voltge Vboot Vec=24V 5.4 6.5 7.6 Vv Internal reference voltage Vref Vec=8V-40V 4.75 5 5.25 Vv Internal oscillation frequency fosc Vec=24V 212.5 250 287.5 kHz Overcurrent threshold voltage Vth_OCL Vec=24V 0.162 0.19 0.218 Vv SoftStart terminal current Is/s Vec=24V -20 -12.5 -5 HA ErrorAmp reference voltage Vamp Vec=8V-40V 2.4 2.45 25 Vv Overcurrent protection operating temperature T_TSD _ - 150 -_ C <Recommended operating conditions> <Output current derating> Item Recomm.Value Unit Output Input voltage ( Ta=-10 to +85C ) 8.0-40 Vv Set voltage Current Input voltage ( Ta=-30 to -10C) 8.5-40 Vv 2.5V - 8V 3A Output voltage setting range 2.5-12 V <= 12V 2.5A Operating temperature 30 to 85 C BDD200504 12-050704 Bellnix DC-DC CONVERTERS Power I BiCt422 2Bellnix Power IC BiC1422 <Block diagram> Vref Vec Vboot VB VGH VDD (){6) 93)\(18-21 On/Oft START UP BOOT High Side R/C )}I circuit [77 Starts? 2 |>]Reference=6. 5V Vref=Vout+5. 8V Ref Ne Tpper/ Tower NOS | F s eference pper/|ower igh Side 5. 0OV45% a> Simultaneously OFF] Sher E E NO Pit Conp Sis eau Ok CD) vour y Low Side > | 3V Vref=6. 5V. VA AVANY Osc =250KHz R t 6)P. GND @) @) amp- ampOUT S/S OCL- OCL+ GND VGL <External dimensions> ee 14.4max. AAHAAARRRARARRARA | OA Bellnix S| w| Ww BIC1422 | 2 8 @ P00111 HHEHBEHEREREEHHR Uy 1 16 Detail of A portion = A portion oe / [s] portion Soom = _| TT = a a0 : L = Terminal S oj 3 0.8 (510.10 |S] base: Cu s a ba 0.3501 Dimensions: mm _ Plating: Ni/ Pd/ Au a] A] So Ey 0.16 @I[S] 3 Bellnix DC-DC CONVERTERS Case Black epoxy resin (UL94 V-0) BDD200504 12-050704Bellinix Power IC BIC1422 < Terminal functions > Terminal No. | Symbol Function 1 S/S Soft-start capacitor terminal 2 OCL- |Over-current detection terminal ( - } 3 OCL+ |Over-current detection terminal ( + ) 4,26 GND {Ground terminal 5 R/C |Remote ON/OFF control terminal _ meg 6 Vec [Control circuit power supply terminal ons ets 8 Vboot [Main switch MOSFET control circuit power supply terminal Ce a ee 9 VGL [Low side MOSFET gate terminal for synchronous rectification R/C 5 w w 1~14 VOUT [Power supply output terminal vonoe : B ce oS oO. 16 P.GND |Output circuit ground terminal NG 40 Ee S > 5 18~21 VDD |Main switch MOSFET power supply terminal wes SN S 23 VGH _ [Main switch high side MOSFET gate terminal VOUT 13 cr INO veut ae = Output boot strap terminal. Used for connecting P.GND :16 cr 25 VB condensers across VB and VOUT terminals to boot OO strap IC internal main switch MOSFET control circuit. 27 VTS _ |Test terminal. Do not connect it to anything. 28 Vref _|Internal reference voltage output terminal 30 ampOUT |Internal error amplifier output terminal 32 amp _|Internal error amplifier reversing input terminal 7,10,15,17 N/C _|No connection terminal (N/C terminal) 22,24,29,31 <Peripheral functions> 4. Over-current sensor ( OCL ) 1. Internal reference voltage ( Vref ) The OCL is a pulse-by-pulse overcurrent sensor. The voltage drop IC internal circuitry reference voltage is provided by the temperature across the external current sensing resistor is measured between compensation reference voltage (5.0V). This reference voltage (Vref) the negative and positive terminals of the OCL. If the voltage drop provides a maximum external output current measured at the terminal exceeds 0.19V, the main switch (MOSFET) opens. of 1 mA. 2. Oscillation circuit ( OSC ) 5. Remote ON/OFF ( RIC ) The oscillation circuit is built into the device. No external oscillat It is a remote terminal for output voltage ON/ OFF control, capacitor nor resistor is required. The oscillation frequency (250KHz) Output On: 0-0.5V (Ground this terminal to GND) is set internally and has a sawtooth wave pattern. The sawtooth wave Output Off: 2.5-5.3V (This terminal is open) pattern cannot be outputted externally. 6. Soft-start ( S/S ) 3. Error amplifier ( Error amp ) It is a capacitor connection terminal for soft-start. The error amplifier senses the DC to DC converter voltage and provides _ The start time is delayed by connecting a capacitor which is for a PWM control signal output. Loop gain between the error amplifier soft-start to this terminal. ampOUT terminal and the negative amp terminal is determined by the Connect a capacitor of approximately 0.1UF to this terminal. connections between the feedback resistor and the capacitor. This provides stable loop compensation throughout the system. BDD20050412-050704 Belinix DC-DC CONVERTERS 4Power IC BiC1422 <Mounting> 1. Soldering pattern reference ( Reflow type) Infrared and air reflow soldering conditions HOGGURH eee - hese sae {Se eg eee Within 2 cycles => ba | 1 260Cmax. 2 | iB 2 > < 230C | o ae, 4 E GOsmax NT 220 rT ren 1 5 160C ee f<- 190C | o : 08 os ||. | 8 _ | | S 140430Sec. | ' 2. Mounting cautions we Vibration and other mechanical disturbances can exert stress on the Time internal parts of the device. Carefully examine your equipment and plac the device where vibration and other shock is minimal. 4. Cleaning cautions 3. Soldering Conditions Carefully remove all flux. Allow time for the soldered areas to The infrared reflow method is recommended. If the soldering time is too long completely dry before using the device. or the soldering temperature is too high, it may damage the function of this IC, so be sure to use within the specified conditions. 5. Resinous Coating 1) Infrared reflow method When remolding after mounting the device to the board, if the curing Temperature profile in the reflow method is as shown in the figure stress of the resinous is strong, it may give stress to the component. at the right. So be careful of choosing the resinous and calcify time. 2) Wave soldering conditions - Pre-heating conditions Center of the case temp.: 80-140C Pre-heating time: 30-60sec - Heating conditions Soldering temp.: 265+5C Heating time: 10+1sec - Heating frequency: one time - Notes Solder bridge will be effected by the land, so give consideration when designing the printed board. 3) Storage conditions After the dampproof package is opened, in an environment of temp. 30C and relative temp. 70% or below: within 168Hrs. 4) Baking conditions One time within 24Hrs. at 125C 5) Soldering Iron When using a soldering iron, execute under the following conditions. - Soldering iron tip temp.: 380410C - Heating time: 341sec - Heating frequency: one time 5 Bellnix DC-DC CONVERTERS BDD200504 12-050704Power IC BIC1422 <Usage> <Remote ON/OFF Control Function> 1. Input protection element connection The remote ON/OFF control function can be used for turning output ON The BIC1422 device has an output current drop function. In the event and OFF without making or breaking the input of power IC device malfunction resulting in excessive input current Output ON: 0-0.5V (This terminal is connected with GND) flow, smoke and flame may be emitted from the equipment. Output Off: 2.5-5.3V (This terminal is opened) To prevent this, install fuse or protective circuitry to the power IC - When the R/C function is not used, be sure to connect R/C terminal (5pin) device input line. Install the fuse or protective circuitry to the positive and ground (4pin and 26pin). side of the input line. Be sure that the fuse or protective circuitry is - The R/C terminal can be turned ON and Off by a switch element such as not too large to effectively protect the circuitry (the input line must be a transistor or MOSFET. However, be sure to add a condenser capable of carrying enough current to blow the fuse). (1000pF-0.1micro F) across the R/C terminal (5pin) and ground (4pin and 26pin) to prevent misoperation by noise. - Since pull-up has been carried out in the module, there is no need of impressing the voltage from the outside. 1. R/C Functional Terminal Internal Equivalent Circuit +Vi DC-DC Converter Load Vin R/G terminal re 2. Overvoltage protection [ The BIC1422 power IC device does not have an overvoltage (voltage | GND surge) protection function. If a malfunction occurs in the device internal circuitry, there may be a voltage surge. Output will reflect this surge and damage to equipment may result. Smoke and flame may be emitted from the equipment. To prevent this, be sure to install voltage surge 2. Method of Connecting R/C Functional Terminals sensing and protection circuitry. There are a number of ways to protect against voltage surge. Figure shows a typical voltage surge protection set-up. The voltage surge sensing and protection circuit should be installed as close as possible to the load (away from the output smoothing capacitor) pc + Load | : Reference part example Overvoltage Protection Circuit +Vin +VoutO ty or FUSE t~.T 1000PF-0.1pF condenser for preventing misoperation by noise Switch element . ZD1 - i +Vi fA Load (such as MOS-FET and transistors) [ BDD20050412-050704 Bellnix DC-DC CONVERTERS 6Bellnix Power I BIC1422 < Standard connections > BIC1422 is a power IC developed for synchronous rectification type chopper method. This IC has built the major components of the controller IC part, high-side and low-side MOSFET for commutating etc. into one package. Accessories such as external choke and capacitor are required for this device. The characteristics of these external parts and the way they are packaged and connected will greatly affect the performance of the device and its circuits. Carefully select these external parts to provide optimum device perfoemance. It is possible to adjust the output voltage between 2.5V-12V by external resistances. Connect as to the set output voltage. 1. For use with output voltage lower than 5.3V 1) Basic input and output terminal connections - 9, 23, 27pins are the test terminals and must be left open. -7, 10, 15, 17, 22, 24, 29 and 31pins are N/C terminals (internally unconnected). - Be sure to prepare and connect the external parts shown in the diagram below.. - The use of a low ESR product is recommended for the output smooth capacitor (C5). 2 ) Standard connections C4 wt C3 " gi jos 11-14 uu _ DC8-40v 46-21 BIC1422 ; s Rp? DC 2.5-5.3V +Vino 00 4-W +Vout b= pbc + TRs Input |c1 t ot pc cOutput = R4 C7 = 83 R6 -Vino O -Vout 3 ) Resistors for setting output voltage Output voltage is adjusted using R5 and R6. R6=2.2K ohm _ R6x (Vout 2. 45) Re 2.45 (Q) - Setting output voltage examples (at R6=2.2K ohm) Set at 2.5V, R5=47 ohm Set at 3.3V, R5=770 ohm (300 ohm+470 ohm) Set at 5.0V, R5=2.3K ohm (1K ohm+1.3K ohm) For output voltage setting resistors (R5,R6), resistors with high temterapture characteristics and high accuracy are recommended. 4 ) Input voltage derating when output voltage is set to 3V or less. The maximum input voltage within the usable input voltage range is determined as follows. Vout i Ss Vin(max) = 0075 (V) 7 Bellnix DC-DC CONVERTERS BDD20050412-050704Bellnix Power IC BIC1422 5 ) Reference parts Reference parts for the standard circuit. Due to conditions, the fixed numbers may change. Output voltage 2.5-5.0V Parts No. Component Output current example Type/ Manufacturer 4A 3A IC 1 MCM|C BIC1422 BIC1422 Bellnix.co.ltd L1 Choke coil 68yH, 1.2A 22uH, 3.6A D1 Diode 18S300 1SS300 Toshiba D2 Schottky barrier diode DiFS6 D1FS6 Shindengen C1 Electrolyte capacitor 50V, 100uF 724mA 50V, 270UF 1580mA Rubycon C2 Ceramic capacitor 25V, 0.047UF 25V, 0.047uF GRM39type or C1608type C3 Ceramic capacitor 25V, 0.1uF 25V, 0.1pF Murata or TDK C4 Ceramic capacitor 25V, 1000PF 25V, 1000PF C5 Electrolyte capacitor 10V, 470unF 72mohm 10V, 1200UF 23mohm Rubycon C Ceramic capacitor 25V, 1000PF 25V, 1000PF GRM39type or C1608type C7 Ceramic capacitor 25V, 0.01UNF 25V, 0.01uF R1 Resistance 0.1W, 1Mohm 0.1W, 1Mohm R2 Resistance (parallel) 0.5W, 0.150hm+5% 0.75W, 0.1ohmt5%x2 R3 Resistance 0.1W, 100Kohm 0.1W, 100Kohm R4 Resistance 0.1W, 10Kohm 0.1W, 10Kohm R5 Resistance Calculation from output voltage set resistance R6 Resistance 0.1W, 2.2Kohm+0.50ohm | 0.1W, 2.2Kohm+0.5% 6 ) Electrical characteristics (Ta=25C) Efficiency and ripple are measured according to external reference parts circuit configuration that is based on standard circuit configuration. Unless otherwise specified, the efficiency and ripple voltage conditions are Vin=12V and lo=rated output current. Output current Item iA 3A Output Voltage (V) 25 3.3 5.0 2.5 3.3 5.0 Input Voltage (V) 8-33 8-40 8-33 8-40 Output current (A) o-14 0-3 Voltage regulation accuracy (%) +6 Efficiency Typ. (%) 86 | 89 | 92 | 84 | 87 91 Oscillation frequency Typ. (kHz) 250 Ripple voltage P-P Typ. (mV) 25 Overcurrent protection (A) Operation / auto-recovery at a current lower than rated current Operating temperature (C) -10 to 85 BDD200504 12-050704 Bellnix DC-DC CONVERTERS 8Bellnix Power IC BIC1422 2. For use with output voltage higher than 5.3V 1) Basic connection of input/output terminals - 9, 23 and 27pins are the test terminals and must be left open. - 7,10, 15, 17, 22, 24, 29 and 31pins are internal non-connecting pins (N/C terminals). - Be sure to prepare and connect the external parts shown in the diagram below. - The use of a low ESR product is recommeded for output smooth capacitor (C5). 2 ) Standard connections C4 D1 c3 i rf iL : al jos 44-14 ul ,_ DC8-40V 18-21 BIC1422 a PC Ba-12 +Vin o- Er FBO. Wy O+Vout R7 Re pe jt RS id Input [ct = | gf be Rg Rid [o,Output ra] | & R6 n -Vino O -Vout 3) Minimum required input voltage The circuit method (step-down type) of this MCM-IC is set at maximum 70% on-duty, so difference between input voltage and output voltage is required. To set the output voltage at 5.6V or more, calculate the minimum input voltage by the equation below. . . Vout Vin(min) 2977 4) Terminal connection of OCL+, OCL- When setting the output voltage higher than 5.3V, decide the resistances of R2, R7, R8, R9 and R10, so that the OCL-, OCL+ (2, 3pin) terminal voltage can become 5.3 or below. R9 = R10= 1k ohm R7 (1+ ~)x0. 19 (Vout +0. 2)-5.3 _ RO R7=R8 2 3 [Koh] R2= lout (OCP) [ohm] When the output voltage exceeds 5.3V, a bridge circuit with R7, R8, R9 and R10 will be composed. The accuracy of the bridge circuit's resistance value will effect the operation of over-current protection. So be sure to choose a resistance with high accuracy (R7-R10 40.5% or below, R2+5% or below). 5 ) Output Voltage setting resistor Output voltage is adjusted using R5 and R6. R6=2.2K ohm _ R6x (Vout 2, 45) ~ 2.45 Rb (2) - Setting output voltage examples (at R6=2.2K ohm) Set at9V, R5=5.9k ohm (2K ohm+3.9K ohm) Set at 12V, R5=8.6K ohm (5.6K ohm+3K ohm) For output voltage setting resistors (R5, R6), resistors with high temperature characteristics and high accuracy are recommended. 9 Bellnix DC-DC CONVERTERS BDD20050412-050704Bellnix 6 ) Reference parts Power IC BiC1422 Referenc parts for the standard circuit. Due to conditions, the fixed numbers may change. Output voltage 5.3V-8V Output voltage 8V-12V Parts No. Component Output current example Output current example 2A 3A 1A 2.5A IC 1 MCMIC BIC1422 BIC1422 BIC1422 BIC1422 L1 Choke 47H, 2.4A 33H, 3 .6A 120yH, 1.2A 47uH, 3A D1 Diode 1$$300 185300 18S300 1$$300 D2 Schottky Diode D1FS6 D1FS6 D1FS6 D1FS6 C1 Electrolyte capacitor | 50V, 180UF 1190mA 50V, 270uUF 1580mA 50V, 100uF 724mA 5OV, 220UF 1370mA C2 Ceramic capacitor 25V, 0.047uF 25V, 0.047uF 25V, 0.047UF 25V, 0.047 UF C3 Ceramic capacitor 25V, 0.1uF 25V, 0.1uF 25V, 0.1UF 25V, 0.1UF C4 Ceramic capacitor 25V, 1000PF 25V, 1000PF 25V, 1000PF 25V, 1000PF C5 Electrolyte capacitor 16V, 680yF 38mohm 16V,1000UF 23mohm_ | 16V, 330uF 72mohm 16V, 680UF 38mohm C6 Ceramic capacitor 25V, 1000PF 25V, 1000PF 25V, 1000PF 25V, 1000PF C7 Ceramic capacitor 50V, 0.01nF 50V, 0.01 UF 50V, 0.01yF 50V, 0.01UF Ri Resistance 0.1W, 1Mohm 0.1W, 1Mohm 0.1W, 1Mohm 0.1W, 1Mohm R2 Resistance It is determined using the equation in 2. 4). R3 Resistance 0.1W, 100Kohm 0.1W, 100Kohm 0.1W, 100Kohm 0.1W, 100Kohm R4 Resistance 0.1W, 10Kohm 0.1W, 10Kohm 0.1Wk 10Kohm 0.1W, 10Kohm R5 Resistance It is determined using the equation in 2. 5). R6 Resistance 0.1W, 2.2Kohm+0.5% | 0.1W, 2.2Kohm+0.5% | 0.1W, 2.2Kohm+0.5% | 0.1W, 2.2Kohm+t0.5% RZ Resistance It is determined using the equation in 2. 4). R8 Resistance RQ Resistance 0.1W, 1Kohm+0.5% 0.1W, 1Kohm+0.5% 0.1W, 1Kohm+0.5% 0.1W, 1Kohm+0.5% R10 Resistance 0.1W, 1Kohm+0.5% 0.1W, 1Kohm+0.5% 0.1W, 1Kohm+0.5% 0.1W, 1Kohm+0.5% 7 ) Electrical characteristics (Ta=25C) Efficiency and ripple are measured according to external reference parts circuit configuration that is based on standard circuit configuration. Unless otherwise specified, the efficiency and ripple voltage conditions are Vin=12V and lo=rated output current. Item Output current example 1A 2.5A Output voltage (V) 12 12 Input voltage (V) 17.5 - 40 13 - 40 17.5 - 40 Output current (A) Voltage regulation accuracy (%) 5 Efficiency Typ. (%) 93 94 94 95 Oscillation frequency Typ.(kHz typ.) 250 Ripple voltage P-P Typ. (mVp-p typ.) 25 Over-current protection (A) Operation/auto-recovery at a current lower than rated current Operating temperature (C) - 30 to + 85 BDD200504 12-050704 Belinix DC-DC CONVERTERS 10Bellnix Power IC 6IC1422 < Basic operation explanation > This Power IC BIC1422 adopts the synchronous rectification method. With this method, the DC-DC converter has high efficiency and supply large current. 1. Basic circuit Vin BIC1422 (8-40V)f~CSCS~~ssCCCCSsS + = Vout(2.5-12V) ao i i Ri { Fen] { rt} + ADI 3 i control FETA i + Ic ZZ Sri ? C2 oO r? rN FET1 : Main switch MOSFET FET2 : Bottom MOSFET D1 : Free Wheeling Diode R1 : Current detection resistance C1: Input Capacitor C2 : Output Capacitor In general step-down chopper converters, the commutation circuit part is composed of diode D1 alone. In synchronous rectification type, FET2 is connected parallel to this commutation diode and the efficiency is improved. Moreover it was general to adopt a P-channel when using a FET as a main switch, however with this Power IC BIC1422 a boost circuit is built-in and the main switching is done at the N-channel of MOSFET, thereby the efficiency can also be improved. 2. Flow of the main current L1 Vin (FETIFON) Co Vout CO Be i ia ] D1 eo SR * rersorrl (a) At ton Current 4 (FET1=OFF} Vin fs a Vout Pee > i pam = : a ~ (FET2=ON) # int 2 SRL (b) At toff Current At ton: Passes FET1 and current flows into L1. At toff: Excitation current that has been saved at L1 go through FET2 (D1) and commutates. 11 Bellnix DC-DC CONVERTERS 3. Main current wave Main Current Wave is shown in the figure below. Vin-Vout lon _ lL ton (IFET1) loff (IFET2+D1) C.c.M. Critical Mode IL D.C.M a = toff + ton toff = C.C.M. Continuous Conduction Mode D.C.M. Discontinuous Conduction Mode At toff, the excitation current of the choke goes through D1, FET2 and commutates. But at the oblique parts it goes through D1 and the middle part goes through FET2. There are three current modes that flow into the choke. The superposed mode of direct current at rating load etc. is called C.C.M. The mode when current that flows into the choke is intermittent at light load is called D.C.M. The boundary between the C.C.M. and D.C.M. is catled the critical mode. At C.C.M., the voltage applied to the choke during ton period becomes Vin-Vo, therefore the current inclination AIL will be Vin-Vo ___ x AIL (ton) = L ton When the FET1 goes off next, the current that has been flowing into the inductance will try to keep flowing into the same direction. So, it will go through D1, FET2 and start commutation. For the commutating current, the same current value of the value right before FET1 went off will flow, and the same voltage as the output voltage will be added to the both ends of L1. Therefore the current inclination JIL when off will be =" y tort AIL (toff) L And for C.C.M. the current inclination JIL is the same, so it will be o = 10" yin = tO Vin ton+ toff T To calculate the smooth choke inductance, design it so that the critical operation can be 15-20% of the rating current. Therefore, the inductance can be calculated with the equation below. _ Vin = Vo L Vin - Vo Vo AML (0.15 to 0.2)xlox2 Vinxf x ton= BDD200504 12-050704Power IC BiC1422 <Basic device set-up standards> In the following order, the addition parts are designed. 1. Over-current detecting resistor (R1) selection 2. Inductance (L1) selection 3. Output capacitor (C2) selection 4. input capacitor (C1) selection 1. Over-current detecting resistor (R1) selection method (Output voltage 5.3V or below) The output current is detected by the drop voltage of resistor R1. The over-current protection circuit of pulse by pulse method operates when the voltage generated at the resistance is 0.19V+15%. _ Vth RI= Iocp [ohm] Vth: Over-current detecting voltage (0.19V15%) locp: Over-current operating point At the over-current operating point, the maximum output current will be set at 110-120%. At the over-current operating point, switching noise and other factors may cause some variation in the calculated value. Check your own equipment and calculate the value accordingly. 2. Inductance ( L1 ) selection Inductance is determined so that JIL is 15 to 20% of the rating output current at the maximum input voltage. lig Win (max) Vo) x Vo cH] AIL x Vin(max) x f Vin (max): Maximum input voltage Vo: Output voltage AIL: 15-20% of output current (0.15 to 0.2 x lo) f: Oscillation frequency (250kHz) Regarding choke coil selection, be careful of direct superposition characteristics, not to saturate the choke coil even in the over-current area. BDD200504 12-050704 3. Output capacitor (C2) selection If an electrolytic capacitor is used, output ripple is determined by AIL and capacitor impedance. Use the equation below to calculate the value. Select a device providing an impedance (Zc) lower than the calculated value. Vrip fo IL Vrip: Output ripple voltage (Ex. 30mVp-p) 4IL: 15-20% of output current 4, Input capacitor ( C1 ) selection A large ripple current flows through the input capacitor. Use the equation below to calculate the value. Select a device providing a higher ripple current capacity (Irip) than the calculate value. _ Vo ~ Vi(min) Irip = ./D(1D) xlo D: Duty (Ton/T) Vo: Output voltage Vin (min): Minimum input voltage I o: Output current 5. Thermal management Temperature increase varies with input voltage, output voltage and output current. Case surface temperatures should no exceed 105C. Set up your equipment accordingly. Belinix DC-DC CONVERTERS 12Bellnix Power IC BIC1422 14.2 <Packing> Dimensions: mm 1. Tape & Reel Dimensions comply with JIS, C-0806-3 (3.10) 3 +01 G as! 2.5 #0.1 1PIN x 0.3 7" t \ = @ i@- bx: im = EE =| 5 Ee ae > PE N ue A Direction of feed ! 2. Reel Materials: Polystyrene+Carbon _ Direction of feed | _ oy) ou Se St St: 8} 3} -|---}- e| & 95.57 1 99.519 13 Bellnix DC-DC CONVERTERS BDD200504 12-050704Bellnix Power I BIC1422 3. Leader and Trailer Trailer (160mm min.) Device Top cover (400mm min.) N# ~ OO eeveese O00 0 covce((seecece OO eeeoee OC Direction of feed Leader (100mm min.) BDD200504 12-050704 Bellnix DC-DC CONVERTERS 14<Precautions> - This product is for being used in general electric equipments (business equipments, telecommunication equipments and measurement equipments). May not be used in medical equipments, nuclear equipments and trains which would affect lives or properties directly by the failure of this product. - Do not remodel, process or use in a non-standard, it may cause serious accidents. We can not take responsibility for those products used in a wrong way or in a non-standard. - When there is a problem, an excessive voltage may occur to the output and cause voltage decrease. Built-in a protection circuit (over-voltage protection, over-current protection etc. ) assuming to have problems of malfunction and damage of equipments. - Always keep the standards (input voltage, operating temperature and so on), without fail and be sure to insert a protection element to the input line. Also, always confirm each polarity (input and output) that there is no miss wiring before energizing. <<Wrong way of using will cause smoke fire.>> - This product does not have a built-in over-voltage protection. When over-voltage occurs due to the abnormality in the module, there is a mode that input voltage comes out at it is, and may cause smoke and ignition. To prevent this, be sure to add over-voltage protection. <<When over-voltage occurs, the remote ON/ OFF pin of this IC do not function .>> - The contents specified herein are accurate and reliable, however we shall not take any responsibilities for any damages and loss or infringement of patent and any other rights, as a result of using these materials. - This material does not guarantee the execution of patent or other rights of third party or approve the right of execution hereof. - Reprinting and copying these materials are not allowed partially or totally without our prior written approval. |Export regulations for stragety goods | - Classified into integrated circuits, in the export regulations 1-7 section of the attached table, and the ordiance of the Ministry of Economy, Trade and Industry clause 6. * - This product is a subject for KNOW regulation. elin q co Bellnix a Bellnix. Co., Ltd. eit 5-7-8 Negishi Minami-ku Saitama-shi, Saitama, JAPAN 336-0024 TEL: 048-864-7733 FAX: 048-861-6402 E-mail: info@bellnix.co.jp URL: http://Awww.bellnix.co.jp/ *All specification are subjected to change without notice. Printed in Japan BD20050412-050704 Dream and Creation