Quasi-Resonant type AC/DC converter IC BD768xFJ-LB series Quasi-Resonant converter Technical Design 24V / 1A ( SIC TO-3PFM SCT2H12NZ) This application note describes the design of Quasi-Resonant converters using ROHM’s AC/DC converter IC BD768xFJ-LB series devices. It explains the selection of external components and PCB layout guidelines. ● Description The BD768xFJ-LB series are Quasi-Resonant switching AC/DC converter for driving SiC (Silicon Carbide)–MOSFET. Using external switching MOSFET and current detection resistors provides a lot of flexibility in the design. Power efficiency is improved by the burst function and the reduction of switching frequency under light load conditions. This is the product that guarantees long time support in the Industrial market. ● Key features Quasi-resonant method（Maximum frequency control 120kHz）/Current mode Low power when load is light ( Burst operation) / Frequency reduction function VCC pin : under voltage protection / over voltage protection Leading-Edge-Blanking function Over-current protection (cycle-by-cycle) ZT trigger mask function ZT Over voltage protection AC voltage correction function Soft start Brown IN/OUT function Gate Clamp circuit MASK Function ● Basic specifications Operating power supply voltage range(VCC): Operating current ：VCC：15.0V～27.5V Normal mode ：0.80mA (Typ.) Burst mode ：0.50mA(Typ.) Maximum frequency ：120kHz(Typ.) Operating temperature range ：-40℃ to +105℃ (＊) Product structure：Silicon monolithic integrated circuit This product has no designed protection against radioactive rays (＊) Operating the IC over the absolute maximum ratings may damage the IC. The damage can either be a short circuit between pins or an open circuit between pins and the internal circuitry. Therefore, it is important to consider circuit protection measures, such as adding a fuse, in case the IC is operated over the absolute maximum ratings. ● BD768xFJ-LB Series line-up BD7682FJ BD7683FJ BD7684FJ BD7685FJ FBOLP AutoRestart Latch AutoRestart Latch VCCOVP Latch Latch AutoRestart AutoRestart ● Applications Industrial equipment, AC Adaptor, Household appliances www.rohm.com © 2016 ROHM Co., Ltd. All rights reserved. 1/24 2016.04.06 Rev.A Application Note BD768xFJ-LB series Quasi-Resonant converter Technical Design ● Block Diagram VH FUSE Filter VOUT Rstart RH Diode Bridge Va RL Cvcc 8 7 BO VCC BO Comp. VCC UVLO + + - - 15uA 1.0V 4.0V Regulator Internal 18.5V/14.0V 18.0V Clamper Supply NOUT + - ZT ACSNS Comp. + VCC OVP + - Rzt1 ZT 1 ZT OVP Comp. (LATCH) ZT Comp. + TimeOut ( 15 usec ) 7V Rzt2 ZT Blanking OUT(H->L) 0.60us 100mV /400mV OSC + - ERROR AMP OR POUT AND S Q NOUT FBOLP_OH AND OR MAX Blanking Frequency (120kHz) + VREF(4V) OSC 1 shot AND - Czt 28.0V 5 OUT PRE Driver NOUT R 1.00V 20k FB 2 + Burst Comp. - 0.50V Cfb 6 OLP + - Timer (128ms) MASK 0.5μs Delay FBOLP_OH NOR Soft Start 200kΩ 200kΩ FB/2 1.00V - DCDC Comp. SS1ms SS4ms + CURRENT SENSE (V-V Change) Normal : ×1.0 Leading Edge Blanking 3 CS RS 4 GND PC www.rohm.com © 2016 ROHM Co., Ltd. All rights reserved. 2/24 2016.04.06 Rev.A BD768xFJ-LB series Quasi-Resonant converter Technical Design Application Note Contents 1. Design of Isolated Fly-buck Quasi-Resonant convertor 1-1．Transformer T1 design 1-1-1．Determination of fly-back voltage VOR 1-1-2．Determination of Minimum frequency fsw and calculation of primary -side winding inductance Lp 1-1-3．Determination of transformer size 1-1-4．Calculation of primary-side turn count Np 1-1-5．Calculation of secondary-side turn count Ns 1-1-6．Calculation of VCC turn count Nd 1-1-7．Transformer design 1-2．Selection of main components 1-2-1．MOSFET:Q1 1-2-2．Input capacitor: C2,C3,C4 Balance resistance: R1,R2,R3,R4,R5,R6 1-2-3．Current-sensing resistor: R19 Resistance for noise protection of CS terminal:R22 1-2-4．Overload protection correction setting resistor : R20 1-2-5．Setting resistor for ZT terminal voltage: R21 1-2-6．ZT terminal capacitor: C11 1-2-7．VCC-diode: D18 1-2-8．VCC winding surge-voltage limiting resistor: Rvcc1 1-2-9．VCC starter resistance ；R11,R12,R13,R14 capacitance；C5,C6 and Rectifier diode；D19 1-2-10．Brown IN/OUT resistance: R7,R8,R9,R10,R15 and BO capacitor: C8 1-2-11．Snubber circuits: Csnubber1,Rsnubber1,D13,D14,D15,D16 1-2-12．FB terminal capacitor: C12 1-2-13．MOSFET gate circuit: R16,R17,R18,D17 1-2-14．Output rectification diode: ND1 1-2-15．Output capacitors: Cout1,Cout2,Cout3,Cout4 1-2-16．Output voltage setting resistors: R25,R26,R28 1-2-17．Parts for adjustment of control circuit: R24,R27,R32,C15 1-3．EMI countermeasures 1-4．Output noise countermeasures 1-5．Proposed PCB layout 2. Evaluation result 2.1. Evaluation circuit and parts list 2.2. Evaluation Result (Efficiency) 2.3. Evaluation Result (Waveform) www.rohm.com © 2016 ROHM Co., Ltd. All rights reserved. 3/24 2016.04.06 Rev.A BD768xFJ-LB series Quasi-Resonant converter Technical Design Application Note １．Design of Isolated Fly-buck Quasi-Resonant convertor Quasi-resonant converter is self-excited fly-back converter power supply system using the voltage resonance of the transformer primary winding inductor and resonant capacitor. Generally, Quasi-resonant converter is possible to reduce the loss and noise than the PWM fly-back converter. Quasi-Resonant Converter becomes DCM (Discontinuous Conduction Mode) under light load, and switching frequency increases with the load increasing. When the load increased further, Quasi-Resonant Converter becomes BCM (Boundary Conduction Mode), and switching frequency decreases with the load increasing. The relation of switching Frequency and output load characteristics is shown in Figure 1-2. The Switching waveform at DCM and CCM is shown in Figure 1-2. Switching Frequency Boundary point DCM BCM Output Load Figure 1-1.Switching Frequency – Output Load Characteristics IC detects Bottom and controls a timing of switching turn ON. BCM DCM Figure 1-2.Switching waveform (MOSFET Vds,Ids) www.rohm.com © 2016 ROHM Co., Ltd. All rights reserved. 4/24 2016.04.06 Rev.A Application Note BD768xFJ-LB series Quasi-Resonant converter Technical Design 1-1．Transformer T1 design (24V1A, Vin(DC)=300V～900V) 1-1-1．Determination of fly-back voltage VOR Turns-ratio Np:Ns and duty-ratio is determined along with Fly-back voltage VOR Np ton VIN Ns toff Np VOR Ns VO VOR Duty VIN VOR VOR VO VIN→ VOR When VIN(MIN)=300V, VOR=204V, Vf=1.5V: GND→ Np VOR VOR 204V 8.0 Ns VO Vout Vf 24V 1.5V VOR 204V Duty(max) 0.405 VIN(min) VOR 300V 204V Figure1-3．MOSFET Vds (*) VOR is adjusted to set it below 0.5 in consideration of MOSFET’s loss. 1-1-2．Determination of Minimum frequency fsw and calculation of primary side winding inductance Lp The primary side maximum current Ippk and the primary side winding inductance Lp is determined from the minimum input voltage（VIN=300V） and the minimum frequency (Fsw=92kHz). Other’s parameter is following: Po=24V × 1A=24W, Po (max)=30W(de-rating 0.8) in consideration of over current protection. Transformer efficiency:η=85% Resonance capacitor: Cv=100pF 2 VIN (min) Duty (max) 1755uH Lp 2 Po(max) fsw VIN(min) Duty (max) fsw Cv Ippk 2 Po (max) 0.662 A η Lp fsw 1-1-3．Determination of transformer size Core size of the transformer is determined to EFD30 by the condition of Po(max)=30W. Table 1-1. Output Voltage and Transformer Core Core sectional area Ae (mm2) ~30 EI25/EE25 41 ~50 EFD30 68 ~60 EI28/EE28/EER28 84 ~80 EI33/EER35 107 (*) The above is guideline values. For details, check with the transformer manufacturer, etc. Output power Po(W) www.rohm.com © 2016 ROHM Co., Ltd. All rights reserved. Core size 5/24 2016.04.06 Rev.A BD768xFJ-LB series Quasi-Resonant converter Technical Design Application Note 1-1-4．Calculation of primary-side turn count Np Generally, the maximum magnetic flux density B(T) for an ordinary ferrite core is 0.4T @100°C, so Bsat = 0.3T. Np Lp Ippk 1750uH 0.66A 57turns Ae Bsat 68mm 2 0.3T In order not to cause a magnetic saturation, the IC must be used in areas that do not saturate from AL-Value-NI characteristics. In the case of Np=50 turns: AL Value Np=50turns AL-Value=700nH/turns2 NI=33A・turns Lp 1750uH 700nH / turns 2 Np 2 50turns 2 NI Np Ippk 50turns 0.66A 33A･turns Transformer is saturated based on the AL-value－NI characteristics. Set the number of primary winding so as not to be saturation region. In the case of Np=64 turns: AL Value Lp 1750uH 427nH / turns 2 Np 2 64turns 2 Np=64turns AL-Value=427nH/turns2 NI=42.2A・turns Figure 1-4. NI Np Ippk 64turns 0.66A 42.2A･turns AL-Value－NI Limit Reference Characteristics In this case, this point is within the tolerance range Np = 64 turns is determined 1-1-5．Calculation of secondary-side turn count Ns Np 64 8 Ns 8 turns Ns 8 1-1-6．Calculation of VCC turn count Nd When VCC=24V, Vf_vcc=1V, Nd Ns VCC Vf_vcc 24V 1.0V 8turns 7.8turns Vout Vｆ 24V 1.5V (*)In the case of driving SiC-MOSFET, since it is necessary to control the Gate voltage, VCC is required more than 22V. As a result, the transformer specifications are as follows. Table 1-2. Transformer Specifications Core EFD30 compatible Lp 1750uH Np 64 turns Ns 8 turns Nd 8 turns www.rohm.com © 2016 ROHM Co., Ltd. All rights reserved. 6/24 2016.04.06 Rev.A BD768xFJ-LB series Quasi-Resonant converter Technical Design Application Note 1-1-7. Transformer design White Marking dot www.rohm.com © 2016 ROHM Co., Ltd. All rights reserved. 7/24 2016.04.06 Rev.A Application Note BD768xFJ-LB series Quasi-Resonant converter Technical Design 1-2．Selection of main components 1-2-1．MOSFET:Q1 For MOSFET selection, it must be considered maximum voltage between the drain and source, peak current, losses due to Ron, maximum power dissipation of the package. At low input voltage, the ON time of the MOSFET becomes long and the heat generated by Ron loss is bigger. Be sure to confirm the state incorporated in the product and execute the heat dissipation of the heat sink as needed. Current rating should be selected twice about Ippk. Vds (max) VIN (max) VOR Vspike VIN (max) Vout Vf Np 64turns Vspike DC900V (24V 1.5V ) Vspike Ns 8turns 1104V Vspike Calculation of Vspike is difficult. MOSFET breakdown voltage is 1700V by using a snubber circuit. In this design example, ROHM’s MOSFET SCT2H12NZ(1700V 4A 1.15Ω) is selected . Below show the typical characteristics of SCT2H12NY. Please refer to the SCT2H12NY data sheet for formal data. ○ABSOLUTE MAXIMUM RATINGS [Tj=25oC] ・・・ 1700V GATE-SOURCE VOLTAGE VDSS VGSS ・・・ -6V ～ +22V DRAIN CURRENT CONTINUOUS ID ・・・ ±4A （Limited by Tj） RAIN CURRENT PULSED IDP ・・・ ±10A PW≦10µs SOURCE CURRENT CONTINUOUS IS ・・・ 4A （BODY DIODE. Limited by Tj.） SOURCE CURRENT PULSED ISP ・・・ 10A PW≦10µs DRAIN-SOURCE VOLTAGE DUTY CYCLE≦1% DUTY CYCLE≦1% （BODY DIODE.） TOTAL POWER DISSIPATION PD JUNCTION TEMPERATURE Tj RANGE OF STORAGE TEMPERATURE Tstg PARAMETER GATE-SOURCE LEAKAGE CURRENT GATE-SOURCE LEAKAGE CURRENT DRAIN-SOURCE BREAKDOWN VOLTAGE ITEM ・・・ 44W ・・・ 175 oC ・・・ -55～175 oC CONDITION MIN. TYP. MAX. － － 100nA IGSS＋ VGS=+22V/VDS=0V IGSS- VGS=-6V/VDS=0V － － -100nA V(BR)DSS ID=1mA/VGS=0V 1700V － － ZERO GATE VOLTAGE DRAIN CURRENT IDSS VDS=1700V/VGS=0V － 0.1μA 10μA GATE THRESHOLD VOLTAGE VGS(th) VDS= VGS /ID=410μA STATIC DRAIN-SOURCE ON-STATE RESISTANCE RDS(on) *PULSED ID=1.1A/VGS=18V Tj=25oC ID=1.1A/VGS=18V Tj=125oC TRANSCONDUCTANCE gfs *PULSED VDS=10V/ID=1.1A INPUT CAPACITANCE Ciss OUTPUT CAPACITANCE Coss REVERSE TRANSFER CAPACITANCE Crss GATE INPUT RESISTANCE Rg TURN-ON DELAY TIME RISE TIME TURN-OFF DELAY TIME FALL TIME TOTAL GATE CHARGE GATE-SOURCE CHARGE GATE-DRAIN CHARGE www.rohm.com © 2016 ROHM Co., Ltd. All rights reserved. td(on) *PULSED tr *PULSED td(off) *PULSED tf *PULSED Qg *PULSED Qgs *PULSED Qgd *PULSED VDS=800V/VGS=0V f=1MHz f=1MHz open Drain VDD=500V ID=1.1A VGS=18V/0V RL=455Ω RG=0Ω VDD=500V ID=1A VGS=18V RL=500Ω 8/24 1.6V － 4.0V 0.80Ω 1.15Ω 1.50Ω － 1.71Ω － － 0.4S － － 184pF － － 16pF － － 6pF － － 64Ω － － 16.3ns － － 20.9ns － － 35.1ns － － 73.8ns － － 14nC － － 4nC － － 5nC － 2016.04.06 Rev.A Application Note BD768xFJ-LB series Quasi-Resonant converter Technical Design 1-2-2．Input capacitor: C2,C3,C4 Balance resistance: R1,R2,R3,R4,R5,R6 Use Table 1-3 to select the capacitance of the input capacitor. Cmain：1x25=25 → 33uF Since Pout=24Vx1.1A≒25W Table 1-3. Input Capacitor Input voltage（Vdc） Cin（uF） Selection Table < 300 2 x Pout(W) 300< 1 x Pout(W) (*)When selecting, also consider other specifications such as the retention-time. The breakdown voltage of the capacitor is required above the maximum input voltage. VIN(MAX)/de-rating=900V/0.8=1125V Using three 450V breakdown voltage capacitors in series, the breakdown voltage of the capacitor is 450V × 3 = 1350V. As noted, when connecting the capacitors in series, the balanced resistance is required for a constant voltage applied to all capacitors. Since the resistance is in loss, it is recommended to use more resistance 470kohm. CN2 R1,R2,R3,R4,R5,R6’s loss is below. VDC:300~1000V 1 D21 1 D20 2 1 2 1N4007 IN4007 P11_12_13_14_15_16=VN(MAX)×VIN(MAX)/R=900V×900V/2.82Mohm=0.287W DC_IN 2 It is shown in Figure 1-5. HV+ 3 1 2 D5 D9 R7 R11 470k 1M 2 200K D15 Csnubber1 2200pF R31 D16 10 1.5KE 2 2 1 C2 100uF R2 2 2 IN4007 2 1 IN4007 2 1 1 D1 IN4007 2 2 2 R1 470k 1.5KE Rsnubber1 1mH 1 1 L1 R8 5.1 CN1 470k VAR2 D13 1M UF4007 D14 VAR1 R3 UF4007 5.1 C1 3 0.33uF VAR3 470k 100uF R9 R13 470k 470k C9 R4 2 RT3 t VAC:400~690V C3 1 RT2 1 2 2 AC_IN t 1 1 R12 2 1 t RT1 470k 1 D10 1N4007 1 D6 1N4007 1 D2 1N4007 470k 5.1 2 0.33uF R10 470k 1 IN4007 2 IN4007 D11 470k 150 10 D8 D12 1N4007 1N4007 R1 10 470k CIN4 1 2200p L2 R19 2 1mH R22 1.5 1k L4 1 2 Figure 1-5．Input capacitor and Balance resistance 2200p C7 C6 C5 0.1uF 4.7uF 22uF 5 6 0 OUT MASK VCC BO 7 U1 8 CY3 Resistance for noise protection of CS 2200p terminal:R22 The current-sensing resistor limits the current that flows on the primary side to provide protection against output overload. 47pF R15 10k C11 C12 4 CS 3 FB 2 ZT 1 C8 Sensing resistor loss P_R19: GND BD7682FJ Vcs 1.0V R19 1.515Ω Ippk 0.66 A C13 47pF 2200pF 47pF P_R19(peak) Ippk２ R19 0.66 A2 1.5Ω 0.6534W ２ Duty(max) 0.404 R19 0.66A 1.0 0.0586W P_R19(rms) Iprms２ R19 Ippk 3 3 Set the value 1W or above in consideration of pulse resistance. The structure of the resistance may vary the pulse resistance even with the same power rating. Check with the resistor manufacturers for details. www.rohm.com © 2016 ROHM Co., Ltd. All rights reserved. 9/24 2016.04.06 1 10 0 ２ Rvcc1 1 Rev.A 2 2200p 1-2-3．Current-sensing resistor: R19 D19 CY2 1 CY1 2 HV+ 1G R6 D4 1N4007 1 100uF R16 IN4007 2 1 D7 2 1 D3 2 2200p R5 Q R17 2 1 2200p C4 1 1 2200p R14 470k 2 CIN1 1 CIN2 2 CIN3 D17 RB160L-60 2 2 Application Note BD768xFJ-LB series Quasi-Resonant converter Technical Design 1-2-4. Overload protection correction setting resistor: R20 BD768xFJ-LB series has overload protection correction function in the input voltage. After the IC detects overload, there is a delay time to stop the switching operation. This delay is to increase the overload protection point with an increase input voltage. Correction function reduces the current detection level when it equals or exceeds an input voltage value. This function corrects the overload. Since the input voltage range is DC300V ~ DC900V, switching voltage is set to DC400V. Izt is the current flowing from the IC to the transformer Nd winding in time of the switching ON. Izt lower the current detection level at the top than 1mA, overload protection point is lowered. R20 VIN (change) Nd 1 8turns 1 500V 62.5kΩ Np Izt 64turns 1mA Check whether the rating load can be taken after the point of over load protection is switched. When the IC switches CS over current voltage level, it is changed from 1.0V to 0.7V. VIN (change) R20 Ippk ' ton ' Np 64turns Izt 56kΩ 1mA 448V Nd 8turns Vcs 0.70V 0.466 A R19 1.5Ω tdelay toff’ Lp Ippk ' 1750uH 0.466 A 1.64us VIN (change) 496V Ispk ' ton’ Np 64turns Ippk ' 0.466 A 3.728 A Ns 8turns 2 Ns 8turns 1750uH Ls Lp 27.34uH 64turns Np toff ' 2 Ls Ispk ' 27.34uH 3.728 A 3.997us Vout Vf 24V 1.5V tdelay Lp Cv 3.14 1750uH 100 pF 1.31us fsw' Po' 1 1 143kHz ton 'toff 'tdelay 1.64us 3.997us 1.31us Figure 1-6．The waveform of Switching 1 1 Lp Ippk '2 fsw' 1750uH 0.466 A2 120kHz 0.85 19.38W Transformer efficiency:η=0.85 2 2 When Po’ is under the rated output power, R19 has to be adjusted. In this board, furthermore, if the over load point is adjusted by a resistor of 100 kHz, the point is changed to 816V because the maximum frequency of the IC is restricted to 120 kHz. Regarding the over load protection point, please check in an actual product. Figure 1-7. Input voltage correction circuit of overcurrent detection (reference value) www.rohm.com © 2016 ROHM Co., Ltd. All rights reserved. 10/24 2016.04.06 Rev.A BD768xFJ-LB series Quasi-Resonant converter Technical Design Application Note 1-2-5．Setting resistor for ZT terminal voltage: R21 The ZT bottom detected voltage is Vzt1=100mV(typ)（ZT fall）, Vzt2=200mV(typ)（ZT rise）, and ZT OVP(min) is 3.30V, so as a guide, set Vzt to 1V to 3V. Vzt Vout Vf Nd R21 2.7V R21 11.84kΩ Ns R20 R21 1-2-6．ZT terminal capacitor: C11 C11 is a capacitor for stability of ZT voltage and timing adjustment of the bottom detection. Check the waveform of ZT terminal and the timing of bottom detection, and adjust it as necessary. 1-2-7．VCC-diode: D18 A high-speed diode is recommended as the VCC-diode. When D13_Vf=1V, reverse voltage applied to the VCC-diode: Vdr VCC(max) ＋Vf VINmax Nd Np This IC has VCC OVP function, VCC OVP (max) = 31.5V. Reverse voltage of the diode is set so as not to exceed the Vr of diode in conditions of VCC OVP (max). Vdr 31.5V＋1.0V 900V 8turns 145V 64turns With a design-margin taken into account, 145V/0.7≒ 200V → 200V component is selected. （Example: ROHM’s RF05VAM2S 200V 0.5A） 1-2-8．VCC winding surge-voltage limiting resistor: Rvcc1 Based on the transformer’s leakage inductance (Lleak), a large surge-voltage (spike noise) may occur during the instant when the MOSFET is switched from ON to OFF. This surge-voltage is induced in the VCC winding, and as the VCC voltage increases the IC’s VCC overvoltage protection may be triggered. A limiting resistor R16 (approximately 5Ω to 22Ω) is inserted to reduce the surge-voltage that is induced in the VCC winding. Confirm the rise in VCC voltage while the resistor is assembled in the product. www.rohm.com © 2016 ROHM Co., Ltd. All rights reserved. 11/24 2016.04.06 Rev.A BD768xFJ-LB series Quasi-Resonant converter Technical Design Application Note 1-2-9．VCC starter resistance ；R11,R12,R13,R14 capacitance；C5,C6 and Rectifier diode；D18, D19 Start resistance RSTART is the resistance required to start the IC. When the start resistance RSTART value is reduced, the standby power is increased and the startup time is shortened. Conversely, when the start resistance RSTART value is increased, the standby power is reduced and the startup time is lengthened. When BD768xFJ is in standby mode, current I OFF becomes 40µA (Max) However, this is the minimum current required to start the IC. In this case current IOFF is 40µA( Max) with margin. Input voltage VIN_start=180V: VCCUVLO(max)=20V: Ivcc-protected(min)=0.3mA: Rstart (Vcc _ start VCCuvlo(min)) / Istart(max) (180V 20V ) / 40uA 4000kohm Rstart (Vin _ max Vcc _ ovp(max)) / Icc _ protect (900V 31.5V ) / 0.3mA 2895kohm 2895kohm Rstart 4000kohm From the above results, set Rstart = 2940kohm (1Mohm × 2 + 470kohm × 2 series). Start-up time is shown in Figure 1-8. Start up time VS Input Voltage START UP TIME ( SEC) 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0.0 180V 300V 600V 900V 4.7uF 1.8 1.0 0.4 0.3 14.7uF 4.3 2.7 1.3 0.9 Figure 1-8. Start up time A VCC capacitor is needed to stabilize the IC’s VCC voltage. Capacitance of 2.2μF or above is recommended. This example is recommended circuit of Figure 1-9 for the start-up time and stability. At startup, only the C6 works for fast start. After starting, after the output voltage is above a certain voltage, C5 operates. D18 is recommended Low IR Switching diode. (Example Rohm 1SS355VM) R11 1M R12 1M R start C start Figure1-9. resistance of Starter and VCC capacitor www.rohm.com © 2016 ROHM Co., Ltd. All rights reserved. 12/24 2016.04.06 Rev.A BD768xFJ-LB series Quasi-Resonant converter Technical Design Application Note 1-2-10．Brown IN/OUT resistance: R7,R8,R9,R10,R15 and BO capacitor: C8 When the input VH value is low, the brown out function stops the DC/DC operations (The IC itself continues to operate). In the following example, VHON is the operation start VH voltage (L to H), and VHOFF is the operation stop VH voltage (H to L). IC operation start (OFF => ON) (VHON-1.0) /RH = 1.0/RL +15*10e-6 IC operation stop (ON => OFF) (VHOFF-1.0) /RH = 1.0/RL Based on the above, RH and RL can be calculated as follows. RH VHON VHOFF / 15 * 10e 6, RL 1.0 / VHOFF 1.0 * RH VHON=90V、VHOFF=60V: It becomes the circuit shown in Figure 1-10. It should be noted that the BO terminal is required capacitor C8. BO line is weak in noise for high impedance. Recommended is 0.01uF ~ 0.1uF. VIN R7 470k R8 470k R9 470k 5 OUT 6 MASK CS GND 4 2 1 ZT FB C8 0.1uF 3 7 VCC BO R15 33k 8 R10 470k GND Figure 1-10. Broun IN/OUT setting www.rohm.com © 2016 ROHM Co., Ltd. All rights reserved. 13/24 2016.04.06 Rev.A Application Note BD768xFJ-LB series Quasi-Resonant converter Technical Design 1-2-11．Snubber circuits: C snubber 1, R snubber1, D13,D14, D15,D16 Based on the transformer’s leakage inductance (Lleak), a large surge-voltage (spike noise) may occur during the instant when the MOSFET is switched from ON to OFF. This surge-voltage is applied between the MOSFET’s Drain and Source, so in the worst case damage to MOSFET might occur. RCD snubber circuits are recommended to suppress this surge-voltage. (1) Determination of clamp voltage (Vclamp) and clamp ripple-voltage (Vripple) The clamp voltage is determined by the MOSFET’s withstand voltage considering a design margin. Vclamp = 1700V × 0.8 = 1360V The clamp ripple-voltage (Vripple) is set about 50V. (2) Determination of R snubber 1 R snubber 1 is selected according to the following conditions. R snubber 1 2 Vclamp Vclamp - VOR Lleak Ip 2 fsw(max) Lleak = Lp x 10% = 1750uH x 10% = 175uH In the case of Po=25W, VIN(max)=900V, Ip、fsw is calculated 1 Lp Ip 2 fsw 2 1 Vcs fsw Ip ton toff tdelay Lp Rcs Ip Po 1 Ls Vo Vf VIN Np Ip Lp Cv Ns ⇒ Vcs=0.7V, Ip=0.466A, fsw=161kHz Rsnubber 1 2 1360V 1360V - 204V 253kΩ 175uH 0.466 2 120kHz R snubber 1 loss P_ R snubber 1 is expressed as P_R snubber 1 Vclamp - VIN 1360 - 900 1.05W R snubber 1 200kΩ 2 2 A more than 2W component is determined with consideration for design margin. (3) Determination of C snubber 1 Csnubber1 Vclamp 1360V 1607pF Vripple fsw(min) Rsnubber 50V 120kHz 200kΩ The voltage applied to C snubber 1 is 1360V-900=460V. C snubber 1 is set 600V or above with design margin. (4) Determination of D13,D14 Choose a fast recovery diode as the diode, with a withstand voltage that is at or above the MOSFET’s Vds (max) value. The surge-voltage affects not only the transformer’s leakage inductance but also the PCB substrate’s pattern. Confirm the Vds voltage while assembled in the product, and adjust the snubber circuit as necessary. (5) TVS: D15, D16 For excellent protection performance, it is possible to cramp the transient noises. Please determine after checking the withstand voltage and operation waveform. www.rohm.com © 2016 ROHM Co., Ltd. All rights reserved. 14/24 2016.04.06 Rev.A BD768xFJ-LB series Quasi-Resonant converter Technical Design Application Note 1-2-12．FB terminal capacitor: C12 C12 is a capacitor for stability of FB voltage (approximately 1000pF to 0.01uF). 1-2-13．MOSFET gate circuit: R16,R17,R18,D17 The MOSFET’s gate circuits affect the MOSFET’s loss and the generation of noise. The Switching speed for turn-on is adjusted using R16+R17, and for turn-off is adjusted using R16, via the drawing diode D17. (Example: R16：10Ω 0.25W、R17：150Ω、D17：SBD 60V 1A) In the case of Quasi-Resonant converters, switching-loss basically does not occur during turn-on, but it occurs predominantly during turn-off. To reduce switching-loss when the IC turned off, turn-off speed can be increased by reducing R16 value, but sharp changes in current will occur, which increases the switching-noise. Since there is a trade-off relation between loss (heat generation) and noise, measure the MOSFET’s temperature rise and noise while it is assembled in the product, and adjust it as necessary. Also, since a pulse current flows to R16, check the pulse resistance of the resistors being used. R18 is the resistance to pull down the gate of the MOSFET. The recommended value is 10kohm ~ 100kohm. 1-2-14．Output rectification diode: DN1 Choose a high-speed diode (Schottky barrier diode or fast recovery diode) as the output rectification diode. When Vf=1.5V, reverse voltage applied to output diode is Vdr Vout(max) Vf ＋VINmax Ns Np When Vout(max)=24.0V+5%=25.2V: Vdr 25.2V＋1.5V 900V 8 139.2V 64 139.2V/0.7=198V → 200V component is determined with consideration for design margin. Also, diode loss (approximate value) becomes Pd=Vf x Iout=1.5V x 1.0A=1.5W (Example: ROHM’s RFN10T2D：200V 10A, TO-220FN package) Using a voltage margin of 70% or less and current of 50% or less is recommended. Check the rise in temperature while assembled in the product. If necessary, reconsider the component and radiate heat by a heat sink or similar to dissipate the heat. www.rohm.com © 2016 ROHM Co., Ltd. All rights reserved. 15/24 2016.04.06 Rev.A BD768xFJ-LB series Quasi-Resonant converter Technical Design Application Note 1-2-15．Output capacitors: C out 1,C out 2,C out 3, C out 4 Determine the output capacitors based on the output load‘s allowable peak-to-peak ripple voltage (ΔVpp) and ripple-current. When the MOSFET is ON, the output diode is OFF. At that time, current is supplied to the load from the output capacitors. When the MOSFET is OFF, the output diode is ON. At that time, the output capacitors are charged and a load current is also supplied. When ΔVpp = 200mV, ΔVpp ΔVpp 0.2V Z_C＜ 0.0379 Ω at 60kHz (fsw min) Np 64 Ispk Ippk 0.66 A Ns 8 With an ordinary switching power supply electrolytic-capacitor (low-impedance component), impedance is rated at 100 kHz, so it is converted to 100kHz. 60 Z_C＜0.0379 Ω 0.02274 Ω at 100kHz 100 Ripple-current Is (rms): Is(rms) Ispk 1 - Duty 64 1 - 0.261 0.66A 2.62A 3 8 3 The capacitor’s withstand voltage should be set to about twice the output voltage. Vout x 2 = 24V x 2 = 48V → 50V over Select an electrolytic capacitor that is suitable for these conditions. (Example: low impedance type 50V, 470 μF × 3 parallel for switching power supply ) (*) Use the actual equipment to confirm the actual ripple-voltage and ripple-current. 1-2-16．Output voltage setting resistors: R25,R26,R28 When Shunt regulator IC2:Vref=2.495V, R25 R26 82k 4.3k Vo 1 Vref 1 2.495V 24.02V R 28 10k 1-2-17．Parts for adjustment of control circuit: R24,R27,R32,C15 R27 and C15 are parts for phase compensation. Approximately R27=1k～30kΩ、C15=0.1uF, and adjust them while they are assembled in the product. R32 is a resistor which limits a control circuit current. Approximately R32:300 to 2kΩ, and adjust it while it assembled in the product.R24 is a resistor for adjustment of minimum operating current of shunt regulator IC2. In case of IC2: TL431, minimum operating current is 1mA. And when Optocoupler:PC1_Vf is 1V, R24 = 1V / 1mA = 1kΩ 1-3．EMI countermeasures Confirm the following with regard to EMI countermeasures. (*) Constants are reference values. Need to be adjusted based on noise effects. - Addition of filter to input block - Addition of capacitor between primary-side and secondary-side (approximately CY1,CY2+CY3: Y-Cap 2200pF) - Addition of RC snubber to secondary diode www.rohm.com © 2016 ROHM Co., Ltd. All rights reserved. 16/24 2016.04.06 Rev.A BD768xFJ-LB series Quasi-Resonant converter Technical Design Application Note 1-4．Output noise countermeasures As an output noise countermeasure, add an LC filter (approximately L:10μH, C: 10μF to 100μF) to the output. (*) Constants are reference values. Need to be adjusted based on noise effects. VOUT + + + + GND R32 R25 R24 R26 C15 R27 PC 1 2 TL431 R28 Figure1-11．LC Filter Circuit www.rohm.com © 2016 ROHM Co., Ltd. All rights reserved. 17/24 2016.04.06 Rev.A BD768xFJ-LB series Quasi-Resonant converter Technical Design Application Note 1-5．Proposed PCB layout A proposed layout (example) for these circuits is shown in Figure 1-12. ・Double-sided board, lead component view Figure 1-12．Proposed PCB Layout (Example) Figure 1-13. Evaluation board www.rohm.com © 2016 ROHM Co., Ltd. All rights reserved. 18/24 2016.04.06 Rev.A Application Note BD768xFJ-LB series Quasi-Resonant converter Technical Design 2. Evaluation result 2.1. Evaluation circuit and parts list The evaluation circuit is shown in Figure 2-1, parts list is shown in Table 2-1. 2 2 1 IN4007 82 T1 CN3 C14 R23 1 330pF 2 2 Vout 3 L1 1 1 9 8 7 220uF 470uF 470uF 24V/1A 1 1 1 1 2 1.5KE Cout3 Cout4 2 1M VOUT 2 Cout1 Cout2 2 470k 10 L3 2.2uH 0.1uF GND R2 2 2 100uF 1 2 R31 D16 DN1 12 11 10 2 R11 3 Csnubber1 2200pF D15 2 1 R7 200K 1 2 2 C2 IN4007 IN4007 2 1 2 1 470k D9 D5 2 1 2 R1 D1 IN4007 1.5KE Rsnubber1 1mH GND HV+ 3 Vout 1N4007 2 DC_IN D20 D21 1 1 1 VDC:300~1000V CN2 D10 1N4007 1N4007 1N4007 R8 1 1 D6 1 470k 5.1 CN1 D13 1M UF4007 Vout UF4007 R3 RT3 t VAC:400~690V VAR3 R9 470k 100uF R30 R13 C9 27K 470k 0.33uF 2 R4 R14 470k 2 2 2 R5 100uF 470k R29 10 0 N.C R18 10k R6 D8 D12 1N4007 1N4007 470k 1 D4 CIN4 1 L2 R19 2 1.5 R22 1mH 2200p 1k L4 1 2 D19 Rvcc1 1 11 1 CY2 C7 C6 C5 0.1uF 4.7uF 22uF 2 2200p 2200p 2 CY1 1 HV+ LED1 N.C 1G IN4007 IN4007 1N4007 1 C4 150 470k 1 2 1 D11 D7 Q1 R16 2 1 D3 IN4007 2 1 CIN1 2200p 1 CIN2 2200p 2 CIN3 C10 R17 R10 2200p 1 RB160L-60 470k 5.1 D17 1 3 470k 2 C3 0.33uF D 2 C1 5.1 3S RT2 1 2 2 AC_IN t 1 1 R12 D14 VAR1 VAR2 0 2 1 t RT1 470k D2 2 2 D18 5 1 6 0 0 OUT 4 1 2 3 4.7k 1k R27 100k 1K 4 CS 3 FB ZT GND R20 R26 R24 PC817 BD7682FJ 2 82k 2k U2 C15 0.1u C3 1 R25 R32 5 6 7 MASK 2200p VCC BO U1 8 CY3 1 H2 鏍孔 H3 鏍孔 H4 鏍孔 H6 H5 光學點 光學點 47pF R15 10k 2A R C8 H1 鏍孔 C11 C12 47pF 2200pF C13 R21 47pF 12k U3 R28 10K 0 Figure 2-1．Isolated Fly-buck Quasi-Resonant convertor（24V1A=24W） www.rohm.com © 2016 ROHM Co., Ltd. All rights reserved. 19/24 2016.04.06 Rev.A BD768xFJ-LB series Quasi-Resonant converter Technical Design Application Note Table 2-1．Isolated Fly-buck Quasi-Resonant convertor（24V1A=24W） ROHM BD7682FJ-LB Application Board Bill of Materials # 1 Item Part Description Quantity Manufacturer Manufacturer part number CN1 Terminal Block, 3x1, 9.52MM, TH 1 Phoenix Contact 1714984 CN2 Terminal Block, 3x1, 9.52MM, TH 1 Phoenix Contact 1714968 1 WURTH ELECTRONIK 69110171002 CN3 WR-TBL_5.0mm_Horizontal Serie101_THT VAR1 VARISTOR 1080V 10KA DISC 20MM 1 Littelfuse Inc TMOV20RP750E VAR2 VARISTOR 1080V 10KA DISC 20MM 1 Littelfuse Inc TMOV20RP750E VAR3 VARISTOR 1080V 10KA DISC 20MM 1 Littelfuse Inc TMOV20RP750E RT1,RT2,RT3 Fusible ResistorResistor, 2W, 5% 3 Max-Quality Co., LTD FKN2W10JTB C1,C9 Film Cap 0.033UF 1.6KV_DC TH 2 TDK_EPCOS Inc B32672L1333J CAP, X1Y1, 250VAC 3 Rise Power Corp WDE222M9HL C2,C3,C4 AL CAP, 100uF, 450V, +/-20% 3 Nichicon UPT2W101MHD CY1,CY2,CY3 CAP, X1Y1, 1KV 3 Shinyspace Co.,Ltd DY5P222K1K08D L1,L2 HV Inductor, Shielded , 1mH, TH 2 Wurth Elektronik 768772102 Rsnubber1 RES 200K OHM 3W 1% AXIAL 1 Faithful link corp CFSJ100K RVCC1 RES, 11 ohm, 1%, 0.125W, 0805 1 ROHM MCR10ERTF11R0 R1 RES, 470k ohm, 1%, 0.25W, 1206 1 ROHM MCR18ERTF4703 R2 RES, 470k ohm, 1%, 0.25W, 1206 1 ROHM MCR18ERTF4703 R3 RES, 470k ohm, 1%, 0.25W, 1206 1 ROHM MCR18ERTF4703 R4 RES, 470k ohm, 1%, 0.25W, 1206 1 ROHM MCR18ERTF4703 R5 RES, 470k ohm, 1%, 0.25W, 1206 1 ROHM MCR18ERTF4703 R6 RES, 470k ohm, 1%, 0.25W, 1206 1 ROHM MCR18ERTF4703 R7 RES, 470k ohm, 1%, 0.25W, 1206 1 ROHM KTR18EZPF4703 R8 RES, 470k ohm, 1%, 0.25W, 1206 1 ROHM KTR18EZPF4703 R9 RES, 470k ohm, 1%, 0.25W, 1206 1 ROHM KTR18EZPF4703 R10 RES, 470k ohm, 1%, 0.25W, 1206 1 ROHM KTR18EZPF4703 R11 RES, 1M ohm, 1%, 0.25W, 1206 1 ROHM KTR18EZPF1004 R12 RES, 1M ohm, 1%, 0.25W, 1206 1 ROHM KTR18EZPF1004 R13 RES, 470k ohm, 1%, 0.25W, 1206 1 ROHM KTR18EZPF4703 R14 RES, 470k ohm, 1%, 0.25W, 1206 1 ROHM KTR18EZPF4703 R15 RES, 33k ohm, 1%, 0.125W, 0805 1 ROHM MCR10ERTF3302 R16 RES, 10 ohm, 1%, 0.125W, 0805 1 ROHM MCR10ERTF10R0 R17 RES, 150 ohm, 1%, 0.125W, 0805 1 ROHM MCR10PZPZF1000 R18 RES, 10k ohm, 1%, 0.125W, 0805 1 ROHM MCR10ERTF1002 R19 RES, 1 ohm, 5%, 2W, DIP 1 Panasonic ERX-2SJ1R0 CIN1, CIN2, CIN3,CIN4 www.rohm.com © 2016 ROHM Co., Ltd. All rights reserved. 20/24 2016.04.06 Rev.A BD768xFJ-LB series Quasi-Resonant converter Technical Design Application Note R20 RES, 100k ohm, 1%, 0.125W, 0805 1 ROHM MCR10ERTF1003 R21 RES, 12k ohm, 1%, 0.125W, 0805 1 ROHM MCR10ERTF1202 R22 RES, 1k ohm, 1%, 0.125W, 0805 1 ROHM MCR10ERTF1001 R23 RES, 82 ohm, 1%, 0.75W, 1210 1 ROHM MCR100PZHZF82R0 R24 RES, 1k ohm, 1%, 0.125W, 0805 1 ROHM MCR10ERTF1001 R25 RES, 82k ohm, 1%, 0.125W, 0805 1 ROHM MCR10ERTF8202 R26 RES, 4.7k ohm, 1%, 0.125W, 0805 1 ROHM MCR10ERTF4701 R27 RES, 1k ohm, 1%, 0.125W, 0805 1 ROHM MCR10ERTF1001 R28 RES, 10k ohm, 1%, 0.125W, 0805 1 ROHM MCR10ERTF1002 R29 N.C 1 ROHM R30 RES, 30k ohm, 1%, 0.1W, 0603 1 ROHM MCR03ERTF3002 R31 RES, 10 ohm, 1%, 1W, 2512 1 ROHM MCR100JZHF10R0 R32 RES, 1k ohm, 1%, 0.125W, 0805 1 ROHM MCR10ERTF1001 Diode, P-N, 1000V, 1A, TH 14 Pan Jit Inc 1N4007 DIODE FAST REC 1KV 1A DO41 2 Taiwan Semiconductor UF4007 2 Micro Commercial Components 1.5KE200A D1,D2,D3,D4,D5 ,D6,D7,D8,D9,D 10,D11,D12,D20 ,D21 D13,D14 D15,D16 TVS DIODE 274VC AXIAL D17 Schottky diode 40V 1A PMDS 1 ROHM RB160L-40TE25 D18 Super fast diode 200V 0.5A TUMD2M 1 ROHM RF05VAM2STR D19 Diode 90V 0.1A UMD2 1 ROHM 1SS355VMTE17 DN1 Schottky Diode 200V 10A ITO-220AB 1 Diodes, Inc MBR20200CT 1 JOHANSON DIELECTRICS INC 202S41W222KV4E. Csnubber1 Cerm CAP,2200pF, ２KV, 10%, X7R, 1210 C5 AL CAP, 22uF, 35V, +/-20%, TH 1 Nichicon UVR1V220MDD1TD C6 AL CAP, 4.7uF, 35V, +/-20%, TH 1 Nichicon UVR1V4R7MDD1TD 1 Murata GRM21BR71H104JA01L 1 Murata GQM2195C1H470JB01D 1 Murata GQM2195C1H470JB01D 1 AVX 08055C222JAT2A 1 Murata GQM2195C1H470JB01D 1 Yageo 225000111543 1 Taiyo Yuden UMK212BJ104KGHT C7 C8 C10 C11 C12 C13 C14 C15 Cerm CAP, 0.1uF, 35V, +/-10%, X7R, 0805 Cerm CAP, 47pF, 50V, +/-5%, X7R, 0805 N.C Cerm CAP, 47pF, 50V, +/-5%, X7R, 0805 Cerm CAP, 2200pF, 50V, +/-5%, X7R, 0805 Cerm CAP, 47pF, 50V, +/-5%, X7R, 0805 Cerm CAP, 330pF, 1KV, +/-5%, X7R, 1206 Cerm CAP, 0.1uF, 50V, +/-10%, X5R, 0805 Cout1 AL CAP 470uF 35V +/-20% RADIAL 1 HERMEI CORP., LTD LER471M1VG16VR6 Cout2 AL CAP 470uF 35V +/-20% RADIAL 1 HERMEI CORP., LTD LER471M1VG16VR6 www.rohm.com © 2016 ROHM Co., Ltd. All rights reserved. 21/24 2016.04.06 Rev.A BD768xFJ-LB series Quasi-Resonant converter Technical Design Cout3 Cout4 AL CAP 220uF 35V +/-20% RADIAL Cerm CAP, 1uF, 50V, +/-10%, X5R, 0805 Application Note 1 HERMEI CORP., LTD LER221M1VG16VR6 1 Taiyo Yuden UMK212BJ105KG-T U1 IC QR-flyback controller 7SOIC 1 ROHM BD7682FJ-LB U2 Photocoupler 5mA DIP4 1 SHARP PC817 U3 TL431 TO-92 1 UNISONIC CO., LTD TL431 T1 EFD-30 10pin 1 G-CHAN CO., LTD GC-1528 1 Wurth Elektronik 7447462022 L3 Inductor, Shielded core, Metal, 2.2uH 4.3A L4 NC 1 Wurth Elektronik 74476626 HS1 HEATSINK 1 MEICON. CO., LTD. MI-301G-25.4 HS1 HEATSINK 1 MEICON. CO., LTD. MB-217-25 LED1 Smart LED RED 569NM 1 ROHM SML-P11UTT86-RG 1 ROHM SCT2H12NZ Q1 SIC MOSFET N-CH 1700V 4A TO-3PFM www.rohm.com © 2016 ROHM Co., Ltd. All rights reserved. 22/24 2016.04.06 Rev.A BD768xFJ-LB series Quasi-Resonant converter Technical Design Application Note 2.2. Evaluation Result ( Efficiency, switching frequency) Output Power (W) Figure 2-2. Efficiency vs Output Power Figure 2-3 Switching Frequency vs Output Power www.rohm.com © 2016 ROHM Co., Ltd. All rights reserved. 23/24 2016.04.06 Rev.A BD768xFJ-LB series Quasi-Resonant converter Technical Design Application Note 2.3. Evaluation Result (Waveform) VIN(DC)=300V VIN(DC)=600V VIN(DC)=900V Figure 2-4. Drain Voltage and Drain current waveform （VO=24V,IO=1.0A, PO=24W） CH1: Vdrain (200V/div), VIN(DC)=300V CH4: Idrain (200mA/div) VIN(DC)=600V Figure 2-5. Drain Voltage and Drain current waveform CH1: Vdrain (200V/div), www.rohm.com © 2016 ROHM Co., Ltd. All rights reserved. VIN(DC)=900V （VO=24V,IO=2.1A, PO=50W） CH4: Idrain (500mA/div) 24/24 2016.04.06 Rev.A Notice Precaution on using ROHM Products 1. Our Products are designed and manufactured for application in ordinary electronic equipments (such as AV equipment, OA equipment, telecommunication equipment, home electronic appliances, amusement equipment, etc.). If you (Note 1) intend to use our Products in devices requiring extremely high reliability (such as medical equipment , transport equipment, traffic equipment, aircraft/spacecraft, nuclear power controllers, fuel controllers, car equipment including car accessories, safety devices, etc.) and whose malfunction or failure may cause loss of human life, bodily injury or serious damage to property (“Specific Applications”), please consult with the ROHM sales representative in advance. Unless otherwise agreed in writing by ROHM in advance, ROHM shall not be in any way responsible or liable for any damages, expenses or losses incurred by you or third parties arising from the use of any ROHM’s Products for Specific Applications. (Note1) Medical Equipment Classification of the Specific Applications JAPAN USA EU CHINA CLASSⅢ CLASSⅡb CLASSⅢ CLASSⅢ CLASSⅣ CLASSⅢ 2. ROHM designs and manufactures its Products subject to strict quality control system. However, semiconductor products can fail or malfunction at a certain rate. Please be sure to implement, at your own responsibilities, adequate safety measures including but not limited to fail-safe design against the physical injury, damage to any property, which a failure or malfunction of our Products may cause. The following are examples of safety measures: [a] Installation of protection circuits or other protective devices to improve system safety [b] Installation of redundant circuits to reduce the impact of single or multiple circuit failure 3. Our Products are designed and manufactured for use under standard conditions and not under any special or extraordinary environments or conditions, as exemplified below. Accordingly, ROHM shall not be in any way responsible or liable for any damages, expenses or losses arising from the use of any ROHM’s Products under any special or extraordinary environments or conditions. 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The Products are not subject to radiation-proof design. 5. Please verify and confirm characteristics of the final or mounted products in using the Products. 6. In particular, if a transient load (a large amount of load applied in a short period of time, such as pulse. is applied, confirmation of performance characteristics after on-board mounting is strongly recommended. Avoid applying power exceeding normal rated power; exceeding the power rating under steady-state loading condition may negatively affect product performance and reliability. 7. De-rate Power Dissipation depending on ambient temperature. When used in sealed area, confirm that it is the use in the range that does not exceed the maximum junction temperature. 8. Confirm that operation temperature is within the specified range described in the product specification. 9. ROHM shall not be in any way responsible or liable for failure induced under deviant condition from what is defined in this document. Precaution for Mounting / Circuit board design 1. When a highly active halogenous (chlorine, bromine, etc.) flux is used, the residue of flux may negatively affect product performance and reliability. 2. In principle, the reflow soldering method must be used on a surface-mount products, the flow soldering method must be used on a through hole mount products. If the flow soldering method is preferred on a surface-mount products, please consult with the ROHM representative in advance. For details, please refer to ROHM Mounting specification Notice-PGA-E © 2015 ROHM Co., Ltd. All rights reserved. Rev.003 Precautions Regarding Application Examples and External Circuits 1. If change is made to the constant of an external circuit, please allow a sufficient margin considering variations of the characteristics of the Products and external components, including transient characteristics, as well as static characteristics. 2. You agree that application notes, reference designs, and associated data and information contained in this document are presented only as guidance for Products use. Therefore, in case you use such information, you are solely responsible for it and you must exercise your own independent verification and judgment in the use of such information contained in this document. ROHM shall not be in any way responsible or liable for any damages, expenses or losses incurred by you or third parties arising from the use of such information. Precaution for Electrostatic This Product is electrostatic sensitive product, which may be damaged due to electrostatic discharge. Please take proper caution in your manufacturing process and storage so that voltage exceeding the Products maximum rating will not be applied to Products. 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All information and data including but not limited to application example contained in this document is for reference only. ROHM does not warrant that foregoing information or data will not infringe any intellectual property rights or any other rights of any third party regarding such information or data. 2. ROHM shall not have any obligations where the claims, actions or demands arising from the combination of the Products with other articles such as components, circuits, systems or external equipment (including software). 3. No license, expressly or implied, is granted hereby under any intellectual property rights or other rights of ROHM or any third parties with respect to the Products or the information contained in this document. Provided, however, that ROHM will not assert its intellectual property rights or other rights against you or your customers to the extent necessary to manufacture or sell products containing the Products, subject to the terms and conditions herein. Other Precaution 1. This document may not be reprinted or reproduced, in whole or in part, without prior written consent of ROHM. 2. The Products may not be disassembled, converted, modified, reproduced or otherwise changed without prior written consent of ROHM. 3. In no event shall you use in any way whatsoever the Products and the related technical information contained in the Products or this document for any military purposes, including but not limited to, the development of mass-destruction weapons. 4. The proper names of companies or products described in this document are trademarks or registered trademarks of ROHM, its affiliated companies or third parties. Notice-PGA-E © 2015 ROHM Co., Ltd. All rights reserved. Rev.003 Datasheet General Precaution 1. Before you use our Pro ducts, you are requested to care fully read this document and fully understand its contents. ROHM shall n ot be in an y way responsible or liabl e for fa ilure, malfunction or acci dent arising from the use of a ny ROHM’s Products against warning, caution or note contained in this document. 2. All information contained in this docume nt is current as of the issuing date and subj ect to change without any prior notice. Before purchasing or using ROHM’s Products, please confirm the la test information with a ROHM sale s representative. 3. The information contained in this doc ument is provi ded on an “as is” basis and ROHM does not warrant that all information contained in this document is accurate an d/or error-free. ROHM shall not be in an y way responsible or liable for an y damages, expenses or losses incurred b y you or third parties resulting from inaccur acy or errors of or concerning such information. Notice – WE © 2015 ROHM Co., Ltd. All rights reserved. Rev.001