2.7V to 5.5V, 3A 1ch Synchronous Buck Converter integrated FET BD8962MUV ●General Description ROHM’s high efficiency step-down switching regulator BD8962MUV is a power supply designed to produce a low voltage including 0.8 volts from 5.5/3.3 volts power supply line. Offers high efficiency with synchronous rectifier. Employs a current mode control system to provide faster transient response to sudden change in load. ●Key Specifications Input voltage range: Output voltage range: Average output Current: Switching frequency: Highside FET ON resistance: Lowsaide FET ON resistance: Standby current: Operating temperature range: ●Features Offers fast transient response with current mode PWM control system. Offers highly efficiency for all load range with synchronous rectifier (Nch/Nch FET) Incorporates soft-start function. Incorporates thermal protection and ULVO functions. Incorporates short-current protection circuit with time delay function. Incorporates shutdown function. ●Packages VQFN020V4040 2.7V to 5.5V 0.8V to 2.5V 3.0A(Max.) 1MHz(Typ.) 82mΩ(Typ.) 70mΩ(Typ.) 0μA(Typ.) -40℃ to +105℃ 4.0mm x 4.0mm x 1.0mm ●Applications Power supply for LSI including DSP, Micro computer and ASIC ●Typical Application Circuit Fig.1 Typical Application Circuit ○Product structure：Silicon monolithic integrated circuit www.rohm.com © ROHM Co., Ltd. All rights reserved. TSZ22111･14･001 ○This product is not designed protection against radioactive rays. 1/18 TSZ02201-0J3J0AJ00030-1-2 02.MAR.2012 Rev.001 Datasheet BD8962MUV ●Pin Configuration N.C. TOP VIEW ITH ADJ GND 15 14 13 12 11 N.C. 16 10 VCC EN 17 9 BST 18 8 19 7 20 6 PGND 1 2 3 4 PVCC 5 SW Fig.2 Pin configuration ●Pin Description Pin No. 1 2 Pin name SW SW 3 SW 4 5 6 7 8 9 10 SW SW PVCC PVCC PVCC BST VCC SW pin SW pin Pin No. 11 12 Pin name GND ADJ SW pin 13 ITH SW pin SW pin Highside FET source pin Highside FET source pin Highside FET source pin Bootstrapped voltage input pin VCC power supply input pin 14 15 16 17 18 19 20 N.C. N.C. N.C. EN PGND PGND PGND Function Function Ground Output voltage detect pin GmAmp output pin/Connected phase compensation capacitor Non Connection Non Connection Non Connection Enable pin(High Active） Lowside FET source pin Lowside source pin Lowside source pin ●Block Diagram Fig.3 Block Diagram www.rohm.com © ROHM Co., Ltd. All rights reserved. TSZ22111･15･001 2/18 TSZ2201-0J3J0AJ00030-1-2 02.MAR.2012 Rev.001 Datasheet BD8962MUV ●Absolute Maximum Ratings(Ta=25℃) Parameter Symbol VCC VCC Voltage PVCC PVCC Voltage VBST BST Voltage V BST -SW BST_SW Voltage VEN EN Voltage VSW, SW,ITH Voltage VITH Pd1 Power Dissipation 1 Pd2 Power Dissipation 2 Pd3 Power Dissipation 3 Pd4 Power Dissipation 4 Topr Operating temperature range Tstg Storage temperature range Tjmax Maximum junction temperature ＊1 ＊2 ＊3 ＊4 ＊5 Limit 1 -0.3 to +7 * 1 -0.3 to +7 * -0.3 to +13 -0.3 to +7 -0.3 to +7 Units V V V -0.3 to +7 V V V 2 0.34 * 3 0.70 * 4 1.21 * 5 3.56 * -40 to +105 -55 to +150 +150 W W W W ℃ ℃ ℃ Pd should not be exceeded. IC only 1-layer. mounted on a 74.2mm×74.2mm×1.6mm glass-epoxy board, occupied area by copper foil : 10.29mm2 4-layer. mounted on a 74.2mm×74.2mm×1.6mm glass-epoxy board, occupied area by copper foil : 10.29mm2 , in each layers 4-layer. mounted on a 74.2mm×74.2mm×1.6mm glass-epoxy board, occupied area by copper foil : 5505mm2, in each layers ●Operating Ratings(Ta=-40 to +105℃) Parameter Power Supply Voltage EN Voltage Output voltage Setting Range SW average output current ＊6 ＊7 Symbol VCC PVCC VEN VOUT ISW Min. 2.7 2.7 0 0.8 - Ratings Typ. 3.3 3.3 - Max. 5.5 5.5 5.5 6 2.5* 7 3.0* Units V V V V A In case set output voltage 1.6V or more, VccMin = Vout+1.2V. Pd should not be exceeded. ●Electrical Characteristics(Ta=25℃ VCC=PVCC=3.3V, EN=VCC, R1=10kΩ, R2=5kΩ ,unless otherwise specified.) Limit Parameter Symbol Units Conditions Min. Typ. Max. Standby current ISTB 0 10 μA EN=GND Active current ICC 250 500 μA EN Low voltage Standby mode VENL GND 0.8 V EN High voltage Active mode VENH 2.0 Vcc V EN input current IEN 1 10 μA VEN=3.3V Oscillation frequency FOSC 0.8 1 1.2 MHz High side FET ON resistance RONH 82 115 mΩ PVCC=3.3V Low side FET ON resistance RONL 70 98 mΩ PVCC=3.3V ADJ Voltage VADJ 0.788 0.800 0.812 V ITH SInk current ITHSI 10 18 μA VADJ=1V ITH Source Current ITHSO 10 18 μA VADJ=0.6V UVLO threshold voltage VUVLO1 2.400 2.500 2.600 V VCC=3.3V→0V UVLO release voltage VUVLO2 2.425 2.550 2.700 V VCC=0V→3.3V Soft start time TSS 2.5 5 10 ms Timer latch time TLATCH 0.5 1 2 ms Output Short circuit VSCP 0.40 0.56 V VADJ =0.8V→0V Threshold Voltage www.rohm.com © ROHM Co., Ltd. All rights reserved. TSZ22111･15･001 3/18 TSZ2201-0J3J0AJ00030-1-2 02.MAR.2012 Rev.001 Datasheet BD8962MUV ●Typical Performance Curves Fig.4 Vcc - VOUT Fig.5 VEN - VOUT Fig.6 IOUT - VOUT Fig.7 Ta - VOUT www.rohm.com © ROHM Co., Ltd. All rights reserved. TSZ22111･15･001 4/18 TSZ2201-0J3J0AJ00030-1-2 02.MAR.2012 Rev.001 Datasheet BD8962MUV Fig.8 Efficiency Fig.9 Ta - Fosc Fig.10 Ta – RONN, RONP www.rohm.com © ROHM Co., Ltd. All rights reserved. TSZ22111･15･001 Fig.11 Ta - VEN 5/18 TSZ2201-0J3J0AJ00030-1-2 02.MAR.2012 Rev.001 Datasheet BD8962MUV Fig.12 Ta - Icc Fig.13 Vcc - Fosc Fig.14 Soft start waveform www.rohm.com © ROHM Co., Ltd. All rights reserved. TSZ22111･15･001 Fig.15 SW waveform Io=10mA 6/18 TSZ2201-0J3J0AJ00030-1-2 02.MAR.2012 Rev.001 Datasheet BD8962MUV Fig. 16 Transient Response Io=1→3A(10μs) www.rohm.com © ROHM Co., Ltd. All rights reserved. TSZ22111･15･001 Fig.17 Transient Response Io=3→1A(10μs) 7/18 TSZ2201-0J3J0AJ00030-1-2 02.MAR.2012 Rev.001 Datasheet BD8962MUV ●Application Information Operation BD8962MUV is a synchronous rectifying step-down switching regulator that achieves faster transient response by employing current mode PWM control system. ○Synchronous rectifier It does not require the power to be dissipated by a rectifier externally connected to a conventional DC/DC converter IC, and its P.N junction shoot-through protection circuit limits the shoot-through current during operation, by which the power dissipation of the set is reduced. ○Current mode PWM control Synthesizes a PWM control signal with a inductor current feedback loop added to the voltage feedback. ・PWM (Pulse Width Modulation) control The oscillation frequency for PWM is 1 MHz. SET signal form OSC turns ON a highside MOS FET (while a lowside MOS FET is turned OFF), and an inductor current IL increases. The current comparator (Current Comp) receives two signals, a current feedback control signal (SENSE: Voltage converted from I L) and a voltage feedback control signal (FB), and issues a RESET signal if both input signals are identical to each other, and turns OFF the highside MOS FET (while a lowside MOS FET is turned ON) for the rest of the fixed period. The PWM control repeat this operation. SENSE Current Comp RESET VOUT Level Shift R Q FB SET Gm Amp. ITH S IL Driver Logic VOUT SW Load OSC Fig.18 Diagram of current mode PWM control PVCC Current Comp SENSE FB SET GND RESET GND SW GND IL IL(AVE) VOUT VOUT(AVE) Fig.19 PWM switching timing chart www.rohm.com © ROHM Co., Ltd. All rights reserved. TSZ22111･15･001 8/18 TSZ2201-0J3J0AJ00030-1-2 02.MAR.2012 Rev.001 Datasheet BD8962MUV Description of Operations ・Soft-start function EN terminal shifted to “High” activates a soft-starter to gradually establish the output voltage with the current limited during startup, by which it is possible to prevent an overshoot of output voltage and an inrush current. ・Shutdown function With EN terminal shifted to “Low”, the device turns to Standby Mode, and all the function blocks including reference voltage circuit, internal oscillator and drivers are turned to OFF. Circuit current during standby is 0μF (Typ.). ・UVLO function Detects whether the input voltage sufficient to secure the output voltage of this IC is supplied. And the hysteresis width of 50mV (Typ.) is provided to prevent output chattering. Hysteresis 50mV VCC EN VOUT Tss Tss Tss Soft start Standby mode Operating mode Standby mode Standby mode Operating mode UVLO UVLO Operating mode EN Standby mode UVLO Fig.20 Soft start, Shutdown, UVLO timing chart ・Short-current protection circuit with time delay function Turns OFF the output to protect the IC from breakdown when the incorporated current limiter is activated continuously for the fixed time(TLATCH) or more. The output thus held tuned OFF may be recovered by restarting EN or by re-unlocking UVLO. EN 1msec VOUT Output Current in non-control 1/2VOUT Until output voltage goes up the half of Vo or over, timer latch is not operated. (No timer latch, only limit to the output current) Limit Output voltage OFF Latch IL Output Current in control by limit value (With fall of the output voltage, limit value goes down) Standby mode Standby mode Operated mode EN Timer Latch Operated mode EN Fig.21 Short-current protection circuit with time delay timing chart www.rohm.com © ROHM Co., Ltd. All rights reserved. TSZ22111･15･001 9/18 TSZ2201-0J3J0AJ00030-1-2 02.MAR.2012 Rev.001 Datasheet BD8962MUV Information on Advantages Advantage 1：Offers fast transient response with current mode control system. Conventional product (Load response IO=1A→3A) VOUT BD8962MUV (Load response IO=1A→3A) VOUT 62mV 145mV IOUT IOUT Voltage drop due to sudden change in load was reduced by about 50%. Fig.22 Comparison of transient response Advantage 2： Offers high efficiency for all load range with synchronous rectifier. 100 【VOUT=1.2】 Utilizes the synchronous rectifying mode and the low on-resistance MOS FETs incorporated as power transistor. 90 EFFICIENCY: η [%] 80 ON resistance of Highside MOS FET : 82mΩ(Typ.) ON resistance of Lowside MOS FET : 70mΩ(Typ.) 70 60 50 40 30 VCC=5V Ta=25℃ 20 10 0 10 100 1000 OUTPUT CURRENT:IOUT[mA] 10000 Fig.23 Efficiency Advantage 3：・Supplied in smaller package due to small-sized power MOS FET incorporated. ・Output capacitor Co required for current mode control: 22μF ceramic capacitor ・Inductance L required for the operating frequency of 1 MHz: 2.2μH inductor ・Incorporates FET + Boot strap diode Reduces a mounting area required. VCC EN VCC VREF 20mm BST Current Comp RQ S + SLOPE Gm Amp + Soft Start CLK PVCC Current Sense/ Protect OSC VCC UVLO 3.3V Input Cf SW Output Rf PVCC + Driver Logic TSD SCP CBST R2 15mm PGND R1 L CIN RITH GND CITH ADJ Co ITH RITH CITH R1 R2 Fig.24 Example application www.rohm.com © ROHM Co., Ltd. All rights reserved. TSZ22111･15･001 10/18 TSZ2201-0J3J0AJ00030-1-2 02.MAR.2012 Rev.001 Datasheet BD8962MUV Switching Regulator Efficiency Efficiency ŋ may be expressed by the equation shown below: η= VOUT×IOUT ×100[%]= POUT Vin×Iin ×100[%]= Pin POUT POUT+PDα ×100[%] Efficiency may be improved by reducing the switching regulator power dissipation factors P Dα as follows: Dissipation factors: 2 1) ON resistance dissipation of inductor and FET：PD(I R) 2) Gate charge/discharge dissipation：PD(Gate) 3) Switching dissipation：PD(SW) 4) ESR dissipation of capacitor：PD(ESR) 5) Operating current dissipation of IC：PD(IC) 2 2 1)PD(I R)=IOUT ×(RCOIL+RON) (RCOIL[Ω]：DC resistance of inductor, RON[Ω]：ON resistance of FET, IOUT[A]：Output current.) 2)PD(Gate)=Cgs×f×V (Cgs[F]：Gate capacitance of FET, f[H]：Switching frequency, V[V]：Gate driving voltage of FET) 2 Vin ×CRSS×IOUT×f IDRIVE 3)PD(SW)= (CRSS[F]：Reverse transfer capacitance of FET, IDRIVE[A]：Peak current of gate.) 2 4)PD(ESR)=IRMS ×ESR (IRMS[A]：Ripple current of capacitor, ESR[Ω]：Equivalent series resistance.) 5)PD(IC)=Vin×ICC (ICC[A]：Circuit current.) Consideration on Permissible Dissipation and Heat Generation As this IC functions with high efficiency without significant heat generation in most applications, no special consideration is needed on permissible dissipation or heat generation. In case of extreme conditions, however, including lower input voltage, higher output voltage, heavier load, and/or higher temperature, the permissible dissipation and/or heat generation must be carefully considered. For dissipation, only conduction losses due to DC resistance of inductor and ON resistance of FET are considered. Because the conduction losses are considered to play the leading role among other dissipation mentioned above including gate charge/discharge dissipation and switching dissipation. 4 layers (Copper foil area : 5505mm 2) copper foil in each layers. θj-a=35.1℃/W 2 ② 4 layers (Copper foil area : 10.29m ) copper foil in each layers. θj-a=103.3℃/W 2 ③ 4 layers (Copper foil area : 10.29m ) θj-a=178.6℃/W ④IC only. θj-a=367.6℃/W ① Power dissipation:Pd [W] 4.0 ①3.56W 3.0 2 P=IOUT ×RON RON=D×RONP+(1-D)RONN D：ON duty (=VOUT/VCC) RONH：ON resistance of Highside MOS FET RONL：ON resistance of Lowside MOS FET IOUT：Output current 2.0 ②1.21W 1.0 ③0.70W ④0.34W 0 0 25 50 75 100105 125 150 Ambient temperature:Ta [℃] Fig.25 Thermal derating curve (VQFN020V4040) www.rohm.com © ROHM Co., Ltd. All rights reserved. TSZ22111･15･001 11/18 TSZ2201-0J3J0AJ00030-1-2 02.MAR.2012 Rev.001 Datasheet BD8962MUV If VCC=3.3V, VOUT=1.8V, RONH=82mΩ, RONL=70mΩ IOUT=3A, for example, D=VOUT/VCC=1.8/3.3=0.545 RON=0.545×0.082+(1-0.545)×0.07 =0.0447+0.0319 =0.0766[Ω] 2 P=3 ×0.0766＝0.6894[W] As RONH is greater than RONL in this IC, the dissipation increases as the ON duty becomes greater. consideration on the dissipation as above, thermal design must be carried out with sufficient margin allowed. With the Selection of Components Externally Connected 1. Selection of inductor (L) The inductance significantly depends on output ripple current. As seen in the equation (1), the ripple current decreases as the inductor and/or switching frequency increases. (VCC-VOUT)×VOUT ΔIL= [A]・・・(1) L×VCC×f IL ΔIL VCC IL Appropriate ripple current at output should be 20% more or less of the maximum output current. VOUT L ΔIL=0.2×IOUTmax. [A]・・・(2) Co (VCC-VOUT)×VOUT L= Fig.26 Output ripple current ΔIL×VCC×f [H]・・・(3) (ΔIL: Output ripple current, and f: Switching frequency) ※Current exceeding the current rating of the inductor results in magnetic saturation of the inductor, which decreases efficiency. The inductor must be selected allowing sufficient margin with which the peak current may not exceed its current rating. If VCC=5.0V, VOUT=2.5V, f=1MHz, ΔIL=0.2×3A=0.6A, for example,(BD8962MUV) (5-2.5)×2.5 L= 0.6×5×1M =2.08μ → 2.2[μH] ※Select the inductor of low resistance component (such as DCR and ACR) to minimize dissipation in the inductor for better efficiency. 2. Selection of output capacitor (CO) VCC Output capacitor should be selected with the consideration on the stability region and the equivalent series resistance required to smooth ripple voltage. Output ripple voltage is determined by the equation (4)： VOUT L ESR ΔVOUT=ΔIL×ESR [V]・・・(4) Co (ΔIL: Output ripple current, ESR: Equivalent series resistance of output capacitor) Fig.27 Output capacitor www.rohm.com © ROHM Co., Ltd. All rights reserved. TSZ22111･15･001 ※Rating of the capacitor should be determined allowing sufficient margin against output voltage. A 22μF to 100μF ceramic capacitor is recommended. Less ESR allows reduction in output ripple voltage. 12/18 TSZ2201-0J3J0AJ00030-1-2 02.MAR.2012 Rev.001 Datasheet BD8962MUV 3. Selection of input capacitor (Cin) VCC Input capacitor to select must be a low ESR capacitor of the capacitance sufficient to cope with high ripple current to prevent high transient voltage. The ripple current IRMS is given by the equation (5): Cin VOUT IRMS=IOUT× L √VOUT(VCC-VOUT) [A]・・・(5) VCC Co < Worst case > IRMS(max.) IOUT When Vcc=2×VOUT, IRMS= 2 If VCC=3.3V, VOUT=1.8V, and IOUTmax.=3A, (BD8962MUV) Fig.28 Input capacitor √1.8(3.3-1.8) =1.49[ARMS] 3 3.3 . 3 A low ESR 22μF/10V ceramic capacitor is recommended to reduce ESR dissipation of input capacitor for better efficiency. IRMS=2× 4. Determination of RITH, CITH that works as a phase compensator As the Current Mode Control is designed to limit a inductor current, a pole (phase lag) appears in the low frequency area due to a CR filter consisting of a output capacitor and a load resistance, while a zero (phase lead) appears in the high frequency area due to the output capacitor and its ESR. So, the phases are easily compensated by adding a zero to the power amplifier output with C and R as described below to cancel a pole at the power amplifier. fp(Min.) A Gain [dB] 0 fz(ESR) IOUTMin. Phase [deg] 1 2π×RO×CO 1 fz(ESR)= 2π×ESR×CO fp= fp(Max.) IOUTMax. Pole at power amplifier When the output current decreases, the load resistance Ro increases and the pole frequency lowers. 0 -90 fp(Min.)= 1 [Hz]←with lighter load 2π×ROMax.×CO fp(Max.)= 1 2π×ROMin.×CO Fig.29 Open loop gain characteristics [Hz] ←with heavier load A fz(Amp.) Zero at power amplifier Gain [dB] Increasing capacitance of the output capacitor lowers the pole 0 frequency while the zero frequency does not change. (This is because when the capacitance is doubled, the capacitor ESR 0 reduces to half.) Phase [deg] -90 fz(Amp.)= 1 2π×RITH×CITH Fig.30 Error amp phase compensation characteristics www.rohm.com © ROHM Co., Ltd. All rights reserved. TSZ22111･15･001 13/18 TSZ2201-0J3J0AJ00030-1-2 02.MAR.2012 Rev.001 Datasheet BD8962MUV Fig.31 Typical application Stable feedback loop may be achieved by canceling the pole fp (Min.) produced by the output capacitor and the load resistance with CR zero correction by the error amplifier. fz(Amp.)= fp(Min.) 1 2π×RITH×CITH = 1 2π×ROMax.×CO 5. Determination of output voltage The output voltage VOUT is determined by the equation (6): VOUT=(R2/R1+1)×VADJ・・・(6) VADJ: Voltage at ADJ terminal (0.8V Typ.) With R1 and R2 adjusted, the output voltage may be determined as required. L 6 Output SW Co R2 1 ADJ R1 Adjustable output voltage range : 0.8V to 2.5V Fig.32 Determination of output voltage Use 1 kΩ to 100 kΩ resistor for R1. carefully for ripple voltage etc. If a resistor of the resistance higher than 100 kΩ is used, check the assembled set 3.7 The lower limit of input voltage depends on the output voltage. Basically, it is recommended to use in the condition : VCCmin = VOUT+1.2V. Fig.33. shows the necessary output current value at the lower limit of input voltage. (DCR of inductor : 20mΩ) This data is the characteristic value, so it’ doesn’t guarantee the operation range. INPUT VOLTAGE : VCC[V] 3.5 Vo=2.5V 3.3 Vo=2.0V 3.1 Vo=1.8V 2.9 2.7 0 1 2 3 OUTPUT CURRENT : IOUT[A] Fig.33 minimum input voltage in each output voltage www.rohm.com © ROHM Co., Ltd. All rights reserved. TSZ22111･15･001 14/18 TSZ2201-0J3J0AJ00030-1-2 02.MAR.2012 Rev.001 Datasheet BD8962MUV BD8962MUV Cautions on PC Board layout Fig.34 Layout diagram ① Lay out the input ceramic capacitor CIN closer to the pins PVCC and PGND, and the output capacitor Co closer to the pin PGND. ② Lay out CITH and RITH between the pins ITH and GND as neat as possible with least necessary wiring. ※ VQFN020V4040 (BD8962MUV) has thermal PAD on the reverse of the package. The package thermal performance may be enhanced by bonding the PAD to GND plane which take a large area of PCB. Recommended Components Lists on Above Application Symbol Part Value 2.0uH L Coil 2.2uH Manufacturer Sumida Series CDR6D28MNP-2R0NC Sumida CDR6D26NP-2R2NC CIN Ceramic capacitor 22uF Murata GRM32EB11A226KE20 CO Ceramic capacitor 22uF Murata GRM31CB30J226KE18 CITH RITH Ceramic capacitor Resistance Cf Ceramic capacitor Rf Resistance CBST Ceramic capacitor VOUT=1.0V 1500pF Murata CRM18 Serise VOUT=1.2V 1000pF Murata VOUT=1.5V VOUT=1.8V 1000pF 560pF Murata Murata GRM18 Serise GRM18 Serise GRM18 Serise VOUT=2.5V VOUT=1.0V 560pF 5.6kΩ Murata Rohm GRM18 Serise MCR03 Serise VOUT=1.2V VOUT=1.5V 6.8kΩ 6.8kΩ Rohm Rohm MCR03 Serise MCR03 Serise VOUT=1.8V VOUT=2.5V 8.2kΩ 12kΩ Rohm Rohm MCR03 Serise MCR03 Serise 1000 pF Murata GRM18 Serise 10Ω Rohm MCR03 Serise 0.1 uF Murata GRM18 Serise ※The parts list presented above is an example of recommended parts. Although the parts are sound, actual circuit characteristics should be checked on your application carefully before use. Be sure to allow sufficient margins to accommodate variations between external devices and this IC when employing the depicted circuit with other circuit constants modified. Both static and transient characteristics should be considered in establishing these margins. When switching noise is substantial and may impact the system, a low pass filter should be inserted between the VCC and PVCC pins, and a schottky barrier diode or snubber established between the SW and PGND pins. www.rohm.com © ROHM Co., Ltd. All rights reserved. TSZ22111･15･001 15/18 TSZ2201-0J3J0AJ00030-1-2 02.MAR.2012 Rev.001 Datasheet BD8962MUV I/O Equivalence Circuit【BD8962MUV】 ・EN pin PVCC ・SW pin PVCC PVCC EN SW ・ADJ pin ・ITH pin VCC ADJ ITH ・BST pin PVCC PVCC BST SW Fig.35 I/O equivalence circuit www.rohm.com © ROHM Co., Ltd. All rights reserved. TSZ22111･15･001 16/18 TSZ2201-0J3J0AJ00030-1-2 02.MAR.2012 Rev.001 Datasheet BD8962MUV ●Operational Notes 1. Absolute Maximum Ratings While utmost care is taken to quality control of this product, any application that may exceed some of the absolute maximum ratings including the voltage applied and the operating temperature range may result in breakage. If broken, short-mode or open-mode may not be identified. So if it is expected to encounter with special mode that may exceed the absolute maximum ratings, it is requested to take necessary safety measures physically including insertion of fuses. 2. Electrical potential at GND GND must be designed to have the lowest electrical potential In any operating conditions. 3. Short-circuiting between terminals, and mismounting When mounting to pc board, care must be taken to avoid mistake in its orientation and alignment. Failure to do so may result in IC breakdown. Short-circuiting due to foreign matters entered between output terminals, or between output and power supply or GND may also cause breakdown. 4. Thermal shutdown protection circuit Thermal shutdown protection circuit is the circuit designed to isolate the IC from thermal runaway, and not intended to protect and guarantee the IC. So, the IC the thermal shutdown protection circuit of which is once activated should not be used thereafter for any operation originally intended. 5. Inspection with the IC set to a pc board If a capacitor must be connected to the pin of lower impedance during inspection with the IC set to a pc board, the capacitor must be discharged after each process to avoid stress to the IC. For electrostatic protection, provide proper grounding to assembling processes with special care taken in handling and storage. When connecting to jigs in the inspection process, be sure to turn OFF the power supply before it is connected and removed. 6. Input to IC terminals + This is a monolithic IC with P isolation between P-substrate and each element as illustrated below. This P-layer and the N-layer of each element form a P-N junction, and various parasitic element are formed. If a resistor is joined to a transistor terminal as shown in Fig 36. ○P-N junction works as a parasitic diode if the following relationship is satisfied; GND>Terminal A (at resistor side), or GND>Terminal B (at transistor side); and ○if GND>Terminal B (at NPN transistor side), a parasitic NPN transistor is activated by N-layer of other element adjacent to the above-mentioned parasitic diode. The structure of the IC inevitably forms parasitic elements, the activation of which may cause interference among circuits, and/or malfunctions contributing to breakdown. It is therefore requested to take care not to use the device in such manner that the voltage lower than GND (at P-substrate) may be applied to the input terminal, which may result in activation of parasitic elements. Resistor Transistor (NPN) Pin A Pin B C B Pin B E Pin A N N P+ N P+ P N P substrate Parasitic element GND P+ Parasitic element B N P+ P N C E P substrate Parasitic element GND GND GND Parasitic element Other adjacent elements Fig.36 Simplified structure of monorisic IC 7. Ground wiring pattern If small-signal GND and large-current GND are provided, It will be recommended to separate the large-current GND pattern from the small-signal GND pattern and establish a single ground at the reference point of the set PCB so that resistance to the wiring pattern and voltage fluctuations due to a large current will cause no fluctuations in voltages of the small-signal GND. Pay attention not to cause fluctuations in the GND wiring pattern of external parts as well. 8 . Selection of inductor It is recommended to use an inductor with a series resistance element (DCR) 0.1Ω or less. Especially, in case output voltage is set 1.6V or more, note that use of a high DCR inductor will cause an inductor loss, resulting in decreased output voltage. Should this condition continue for a specified period (soft start time + timer latch time), output short circuit protection will be activated and output will be latched OFF. When using an inductor over 0.1Ω, be careful to ensure adequate margins for variation between external devices and this IC, including transient as well as static characteristics. Furthermore, in any case, it is recommended to start up the output with EN after supply voltage is within operation range. Status of this document The Japanese version of this document is formal specification. A customer may use this translation version only for a reference to help reading the formal version. If there are any differences in translation version of this document formal version takes priority www.rohm.com © ROHM Co., Ltd. All rights reserved. TSZ22111･15･001 17/18 TSZ2201-0J3J0AJ00030-1-2 02.MAR.2012 Rev.001 Datasheet BD8962MUV ●Ordering Information B D 8 9 6 2 M U V E2 Package MUV: VQFN020V4040 Part Number Packaging and forming specification E2: Embossed tape and reel ●Physical Dimension Tape and Reel Information VQFN020V4040 <Dimension> <Tape and Reel information> Tape Embossed carrier tape Quantity 2500pcs Direction of feed E2 (The direction is the 1pin of product is at the upper left when you hold reel on the left hand and you pull out the tape on the right hand) 1234 1234 1Pin 1234 1234 1234 1234 Reel (Unit:mm) Direction of feed ※When you order , please order in times the amount of package quantity. ●Marking Diagram VQFN020V4040 (TOP VIEW) Part Number Marking D 8 9 6 2 LOT Number 1PIN MARK www.rohm.com © ROHM Co., Ltd. All rights reserved. TSZ22111･15･001 18/18 TSZ2201-0J3J0AJ00030-1-2 02.MAR.2012 Rev.001 Datasheet Notice ●Precaution for circuit design 1) The products are designed and produced for application in ordinary electronic equipment (AV equipment, OA equipment, telecommunication equipment, home appliances, amusement equipment, etc.). If the products are to be used in devices requiring extremely high reliability (medical equipment, transport equipment, aircraft/spacecraft, nuclear power controllers, fuel controllers, car equipment including car accessories, safety devices, etc.) and whose malfunction or operational error may endanger human life and sufficient fail-safe measures, please consult with the ROHM sales staff in advance. If product malfunctions may result in serious damage, including that to human life, sufficient fail-safe measures must be taken, including the following: [a] Installation of protection circuits or other protective devices to improve system safety [b] Installation of redundant circuits in the case of single-circuit failure 2) The products are designed for use in a standard environment and not in any special environments. Application of the products in a special environment can deteriorate product performance. Accordingly, verification and confirmation of product performance, prior to use, is recommended if used under the following conditions: [a] Use in various types of liquid, including water, oils, chemicals, and organic solvents [b] Use outdoors where the products are exposed to direct sunlight, or in dusty places [c] Use in places where the products are exposed to sea winds or corrosive gases, including Cl2, H2S, NH3, SO2, and NO2 [d] Use in places where the products are exposed to static electricity or electromagnetic waves [e] Use in proximity to heat-producing components, plastic cords, or other flammable items [f] Use involving sealing or coating the products with resin or other coating materials [g] Use involving unclean solder or use of water or water-soluble cleaning agents for cleaning after soldering [h] Use of the products in places subject to dew condensation 3) The products are not radiation resistant. 4) Verification and confirmation of performance characteristics of products, after on-board mounting, is advised. 5) 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. 6) De-rate Power Dissipation (Pd) depending on Ambient temperature (Ta). When used in sealed area, confirm the actual ambient temperature. 7) Confirm that operation temperature is within the specified range described in product specification. 8) Failure induced under deviant condition from what defined in the product specification cannot be guaranteed. ●Precaution for Mounting / Circuit board design 1) When a highly active halogenous (chlorine, bromine, etc.) flux is used, the remainder of flux may negatively affect product performance and reliability. 2) In principle, the reflow soldering method must be used; if flow soldering method is preferred, please consult with the Company in advance. Regarding Precaution for Mounting / Circuit board design, please specially refer to ROHM Mounting specification ●Precautions Regarding Application Examples and External Circuits 1) If change is made to the constant of an external circuit, allow a sufficient margin due to variations of the characteristics of the products and external components, including transient characteristics, as well as static characteristics. 2) The application examples, their constants, and other types of information contained herein are applicable only when the products are used in accordance with standard methods. Therefore, if mass production is intended, sufficient consideration to external conditions must be made. Notice - Rev.001 Datasheet ●Precaution for Electrostatic This product is Electrostatic sensitive product, which may be damaged due to Electrostatic discharge. Please take proper caution during manufacturing and storing so that voltage exceeding Product maximum rating won't be applied to products. Please take special care under dry condition (e.g. Grounding of human body / equipment / solder iron, isolation from charged objects, setting of Ionizer, friction prevention and temperature / humidity control). ●Precaution for Storage / Transportation 1) Product performance and soldered connections may deteriorate if the products are stored in the following places: [a] Where the products are exposed to sea winds or corrosive gases, including Cl2, H2S, NH3, SO2, and NO2 [b] Where the temperature or humidity exceeds those recommended by the Company [c] Storage in direct sunshine or condensation [d] Storage in high Electrostatic 2) Even under ROHM recommended storage condition, solderability of products out of recommended storage time period may be degraded. It is strongly recommended to confirm solderability before using products of which storage time is exceeding recommended storage time period . 3) Store / transport cartons in the correct direction, which is indicated on a carton as a symbol. Otherwise bent leads may occur due to excessive stress applied when dropping of a carton. 4) Use products within the specified time after opening a dry bag. ●Precaution for product label QR code printed on ROHM product label is only for internal use, and please do not use at customer site. It might contain a internal part number that is inconsistent with an product part number. ●Precaution for disposition When disposing products please dispose them properly with a industry waste company. ●Precaution for Foreign exchange and Foreign trade act Since concerned goods might be fallen under controlled goods prescribed by Foreign exchange and Foreign trade act, please consult with ROHM in case of export. ●Prohibitions Regarding Industrial Property 1) Information and data on products, including application examples, contained in these specifications are simply for reference; the Company does not guarantee any industrial property rights, intellectual property rights, or any other rights of a third party regarding this information or data. Accordingly, the Company does not bear any responsibility for: [a] infringement of the intellectual property rights of a third party [b] any problems incurred by the use of the products listed herein. 2) The Company prohibits the purchaser of its products to exercise or use the intellectual property rights, industrial property rights, or any other rights that either belong to or are controlled by the Company, other than the right to use, sell, or dispose of the products. Notice - Rev.001