Large Current External FET Controller Type Switching Regulators Single-output Step-up,High-efficiency Switching Regulator(Controller Type) BD9306AFVM Single-output Step-up,High-efficiency Switching Regulator(Controller Type) BD9305AFVM No.09028EAT04 Description BD9305AFVM / BD9306AFVM are 1-channel DC/DC converter controllers. Step-down DC/DC converter can be configured by BD9305AFVM, and Step-up DC/DC converter can be configured by BD9306AFVM. In addition, the master slave function, which is that the synchronization is possible at the time of multi-connection, is mounted. Features 1) 1ch PWM Control DC/DC Converter Controller 2) Input Voltage Range:4.2 to 18V 3) Feed Back Voltage:1.25±1.6% 4) Oscillating Frequency Variable:100 to 800kHz 5) Built-in Soft Start Function 6) Standby Current of 0 A (Typ.) 7) Built-in Master / Slave Function 8) Protection Circuit : Under Voltage Lockout Protection Circuit Thermal Shutdown Circuit Short Protection Circuit of Timer Latch type 9) MSOP8 Package Applications ・TV, Power Supply for the TFT-LCD Panels used for LCD TVs, Back Lights ・DSC, DVC, Printer, DVD ,DVD Recorder, Generally Consumer Equipments etc. Absolute maximum ratings (Ta = 25°C) Parameter Power supply voltage** Power dissipation Operating temperature range Storage temperature range Maximum junction temperature Symbol Limit Unit Vcc 20 V Pd 588* mW Topr -40 to +85 ℃ Tstg -55 to +150 ℃ Tjmax 150 ℃ * Reduced by 4.7 mW/°C over 25°C, when mounted on a glass epoxy 4-layer board (70 mm 70 mm 1.6 mm) ** Must not exceed Pd. Recommended Operating Ranges (Ta=-40℃ to +85℃) Parameter Symbol Limit Min Typ Max 4.2 12 18 Unit Power supply voltage Vcc Control Voltage VENB － － Vcc V Timing Capacity CT 100 － 1000 pF Timing Resistance RT 5 － 50 kΩ Fosc 100 － 800 kHz Oscillating frequency www.rohm.com © 2009 ROHM Co., Ltd. All rights reserved. 1/14 V 2009.05 - Rev.A Technical Note BD9306AFVM, BD9305AFVM Electrical Characteristics (Unless otherwise specified Ta=25℃,VCC=12V,CT=200pF,RT=20kΩ) Limit Parameter Symbol Unit Min Typ Max Conditions 【Triangular Waveform Oscillator Block】 Oscillating frequency FOSC 165 220 275 kHz Charge Threshold Voltage VOSC＋ 0.80 0.85 0.90 V Discharge Threshold Voltage VOSC－ 0.20 0.25 0.30 V VUT 3.5 － 4.2 V Feed Back Voltage VFB 1.230 1.250 1.270 V Input Bias Current IIB － 0.05 1 µA Vcc=5V 【Under-voltage lockout protection circuit】 Threshold Voltage 【Error amp Block】 FB=1.5V COMP Sink Current IOI 35 50 65 µA FB=1.5V COMP=1.25V COMP Source Current IOO 35 50 65 µA FB=1.0V Ron － 5 － Ω Gate Drive Voltage L VGDL － 0 0.5 V No Load Gate Drive Voltage H COMP=1.25V 【Gate Drive Block】 ON Resistance VGDH Vcc-0.5 Vcc － V No Load MAX Duty (BD9305AFVM) MDT － － 100 % Vcc=5V MAX Duty (BD9306AFVM) MDT － 83 － % Vcc=5V ON Voltage VON 2 － － V OFF Voltage VOFF － － 0.3 V ENB Sink Current IENB 40 60 90 µA TS － 10 － ms Latch Detection COMP Voltage VLC 1.5 1.7 1.9 V Latch Delay OSC Count Number CNT － 2200 － COUNT Latch Delay Time DLY － 10 － ms Standby Current ISTB － 0 10 µA ENB=0FF Average Consumption Current ICC 1.0 1.5 2.5 mA No Switching 【Control Block】 ENB=5V 【Soft Start Block】 Soft Start Time 【Timer Latch Protection Circuit】 【Overall】 *This product is not designed for protection against radio active rays. www.rohm.com © 2009 ROHM Co., Ltd. All rights reserved. 2/14 2009.05 - Rev.A Technical Note BD9306AFVM, BD9305AFVM Electrical Characteristics (Unless otherwise specified,VCC=12V, Ta=25℃) 300 4 Ta=25℃ Ta=85 ℃ 0 Ta=40 ℃ -0.5 Ta=25℃ 2 1 Ta=-40℃ 0 -1 0 1 2 3 4 0 5 Fig.1 Standby Circuit Current 10 15 20 600 400 200 2 3 4 -200 -400 -600 -800 0 5 1 2 3 4 -60 -80 -100 0.5 1 1.5 20 2 2.5 COMP VOLTAGE:VCOMP[V] Fig.7 COMP Source Current www.rohm.com © 2009 ROHM Co., Ltd. All rights reserved. 0.5 1 1.5 2 2.5 COMP VOLTAGE:VCOMP[V] Fig.6 COMP Sink Current 0.1 1.250 1.248 1.246 1.244 0 40 0 FB CURRENT:IFB[μA] REFERENCE VOLTAGE:VFB[V -40 85 0 5 1.252 -20 60 60 Fig.5 GD Source Current 0 35 80 GD VOLTAGE:VGD[V] GD VOLTAGE:VGD[V] Fig.4 GD Sink Current 10 100 -1000 0 -15 Fig.3 Frequency vs Temperature COMP SINK CURRENT:ICOMP[μA] GD SOURCE CURRENT:IGD[mA] 800 1 220 AMBIENT TEMPERATURE:Ta[℃] 0 0 240 200 -40 25 Fig.2 Average Consumption Current 1000 GD SINK CURRENT:IGD[mA] 5 260 INPUT VOLTAGE:VCC[V] INPUT VOLTAGE:VCC[V] COMP SOURCE CURRENT:ICOMP[μA] 280 Ta=85℃ 3 FERQUENCY:FSW[kHz] 0.5 AVERAGE CURRENT:ICC[uA] STAND BY CURRENT:ICC[uA] 1 -40 -15 10 35 60 85 AMBIENT TEMPERATURE:Ta[℃] Fig.8 Feed Back vs Temperature 3/14 0.08 0.06 0.04 0.02 0 0.0 0.5 1.0 1.5 2.0 2.5 FB VOLTAGE:VFB[V] Fig.9 FB Input Bias Current 2009.05 - Rev.A Technical Note BD9306AFVM, BD9305AFVM Electrical Characteristics (Unless otherwise specified,Ta=25℃) Ta=25℃ 150 100 50 125 100 100 75 50 2.5 5.0 7.5 10.0 0 0.0 12.5 ENB VOLTAGE:VENB[V] 90 90 88 86 MAX DUTY:MDT[%] 84 82 80 -40 0.5 1.0 1.5 2.0 50 0 0.0 2.5 0.5 1.0 10 35 60 Fig.11 COMP vs DUTY (BD9305AFVM) Fig.12 COMP vs DUTY (BD9306AFVM) ΔV=166mV Io=1A 78 VCC=12V Vo=5V 400 600 700 800 100 90 90 80 80 70 60 50 VCC=12V Vo=5V Io=SWEEP Fsw=220kHz Ta=25℃ 40 30 www.rohm.com 60 50 VCC=12V Vo=16V Io=SWEEP Fsw=220kHz Ta=25℃ 40 30 10 0.5 1.0 1.5 2.0 OUTPUT CURRENT[A] © 2009 ROHM Co., Ltd. All rights reserved. 70 20 10 0 0.0 Fig.16 Load Response (BD9306AFVM) Fig.15 Load Response (BD9305AFVM) 100 20 VCC=12V Vo=16V 500 Fig.14 Frequency vs MAX Duty (BD9306AFVM) EFFICIENCY:EF[%] Fig.13 Temperature vs MAX Duty (BD9306AFVM) Io=500mA 300 SWITCHING FREQUENCY[kHz] AMBIENT TEMPERATURE[℃] ΔV=380mV 2.5 82 70 200 85 2.0 COMP VOLTAGE:VCOMP[V] 74 -15 1.5 COMP VOLTAGE:VCOMP[V] EFFICIENCY:EF[%] MAX DUTY:MDT[%] Fig.10 ENB Input Current 86 75 25 25 Ta=-40℃ 0 0.0 DUTY CYCLE:DT[%] Ta=85℃ 200 125 DUTY CYCLE:DT[%] ENB CURRENT:IENB[μA] 250 Fig.17 Efficiency Characteristics (BD9305AFVM) 4/14 0 0.0 0.2 0.4 0.6 0.8 1.0 OUTPUT CURRENT[A] Fig.18 Efficiency Characteristics (BD9306AFVM) 2009.05 - Rev.A Technical Note BD9306AFVM, BD9305AFVM Block Diagram FB 1.25V 5 Vref Timer Latch UVLO TSD Shut Down VCC GND COMP Vcc 6 Soft Start Err FB GND COMP 7 8 Shut Down PWM OSC DRV VCC ENABLE 2 1 FB GD ENB CT 4 ENB GD GND 6 COMP 7 8 RT 3 CT RT Vcc 5 Soft Start Err 1.25V Vref Timer Latch UVLO TSD Shut Down Shut Down PWM OSC DRV ENABLE 2 1 3 4 ENB CT RT GD Fig19. Pin Assignment Diagram & Block Diagram (Above:BD9305AFVM / Below:BD9306AFVM) Pin Assignment and Pin Function Pin No Pin Name Function 1 RT Timing Resistance connection Pin 2 CT Timing Capacity connection Pin 3 ENB Control Pin 4 GD Gate Drive Output Pin 5 Vcc Power Supply Pin 6 GND Ground pin 7 COMP 8 FB www.rohm.com © 2009 ROHM Co., Ltd. All rights reserved. Error amp output Pin Error amp inversion input Pin 5/14 2009.05 - Rev.A Technical Note BD9306AFVM, BD9305AFVM Block Diagram / Application Circuit 10000ｐF VCC 5.1ｋΩ FB GND COMP 8 Vcc 6 7 10uF 5 Soft Start Err 1.25V 0.5Ω Vref Timer Latch Shut Down UVLO (When Output Short, TSD Protect Fall VCC) Shut Down 47uH OSC Vo DRV PWM VCC 20uF 1ｋΩ 30ｋΩ 470pF ENABLE 1 3 2 20kΩ 4 ENB CT RT 10ｋΩ 200pF GD 10kΩ VCC Fig.20 Block Diagram / Application Circuit (BD9305AFVM) 10000pF 3.9kΩ FB GND COMP 8 Vcc Soft Start Err 1.25V 10uF 5 6 7 47uH Vref Timer Latch UVLO TSD Shut Down Shut Down Vo PWM OSC DRV 20uF 200kΩ 1kΩ 100pF 15kΩ ENABLE 3 2 1 CT RT 20Ω 200pF 4 ENB GD 10kΩ VCC Fig.21 Block Diagram / Application Circuit (BD9306AFVM) www.rohm.com © 2009 ROHM Co., Ltd. All rights reserved. 6/14 2009.05 - Rev.A Technical Note BD9306AFVM, BD9305AFVM Block Operation ・Error amplifier (Err) It is a circuit that compares the standard voltage of 1.25V (TYP) and the feedback voltage of output voltage. The switching Duty is determined by the COMP terminal voltage of this comparison result. ・Oscillator (OSC) It is a block, in which the switching frequency is determined by RT and CT, and the triangular wave is determined by RT and CT. ・PWM The Duty is determined by comparing the output of Error amplifier and the angular wave of Oscillator. The switching Duty of BD9306AFVM is limited by the maximum duty ratio that is determined by the internal part, and will not be up to 100%. ・DRV The gate of the power FET that is connected to the outside is driven by the switching Duty determined by PWM. ・VREF It is a block that outputs the internal standard voltage of 2.5V (TYP). The internal circuit is entirely the bearer of this standard voltage that is turned ON / OFF by the ENB terminal. ・Protection circuits (UVLO / TSD) UVLO (low-voltage Lock Out circuit) shuts down the circuits when the voltage is below 3.5V (MIN). Moreover, TSD (temperature protection circuit) shuts down the IC when the temperature reaches 175℃(TYP). ・Soft Start Circuit The Soft Start Circuit limits the current at the time of startup while ramping up the output voltage slowly. The overshoot of output voltage and the plunging current can be prevented. ・Timer Latch It is an output short protection circuit that detects the output short if the output of error amplifier (COMP voltage) is more than 1.7V (TYP). If the COMP voltage becomes more than 1.7V, the counter begins to operate, the LATCH is locked when the counter counts to 2200, and the GD output shuts down. (＊the frequency of counter is determined by RT and CT.) Once the LATCH is locked, the GD output does not operate until it is restarted by ENB or VCC. If the output short is removed while the Timer latch is counting, the counter is reset. Selecting Application Components (1) Setting the output L constant (Step Down DC/DC) The inductance L to use for output is decided by the rated current ILR and input current maximum value IOMAX of the inductance. IOMAX + IL should not IL 2 reach the rated value level VCC ILR IOMAX mean current IL L Co t Fig.22 Coil Current Waveform (Step Down DC/DC) Vo Fig.23 Output Application Circuit (Step Down DC/DC) Adjust so that IOMAX + ΔIL / 2 does not reach the rated current value ILR. At this time, ∆IL can be obtained by the following equation. 1 Vo 1 ΔIL= X (Vcc-Vo)X X [A] L Vcc f Set with sufficient margin because the inductance L value may have the dispersion of ± 30%. If the coil current exceeds the rating current ILR of the coil, it may damage the IC internal element. www.rohm.com © 2009 ROHM Co., Ltd. All rights reserved. 7/14 2009.05 - Rev.A Technical Note BD9306AFVM, BD9305AFVM (2) Setting the output L constant (Step Up DC/DC) The inductance L to use for output is decided by the rated current ILR and input current maximum value IINMAX of the inductance. VCC IINMAX+ΔIL should not 2 reach the rated value level IL L IL Vo IINMAX mean current Co t Fig.24 Coil Current Waveform (Step Up DC/DC) Fig.25 Output Application Circuit (Step Up DC/DC) Adjust so that IINMAX + ΔIL / 2 does not reach the rated current value ILR. At this time, ∆IL can be obtained by the following equation. ΔIL= 1 L Vcc X Vo-Vcc Vo X 1 ｆ [A] Where, f is the switching frequency Set with sufficient margin because the inductance L value may have the dispersion of ± 30%. If the coil current exceeds the rating current ILR of the coil, it may damage the IC internal element. (3) Setting the output capacitor For the capacitor C to use for the output, select the capacitor which has the larger value in the ripple voltage VPP allowance value and the drop voltage allowance value at the time of sudden load change. Output ripple voltage is decided by the following equation. ΔIL Vo 1 X X [V] ΔVPP = ΔIL X RESR + 2Co Vcc f ΔVPP = ILMAX X RESR + 1 fCo X Vcc Vo X (ILMAX - (Step Down DC/DC) ΔIL 2 ) [V] (Step Up DC/DC) Perform setting so that the voltage is within the allowable ripple voltage range. For the drop voltage during sudden load change; VDR, please perform the rough calculation by the following equation. ΔI X 10μ sec [V] VDR = Co However, 10 s is the rough calculation value of the DC/DC response speed. Please set the capacitance considering the sufficient margin so that these two values are within the standard value range. (4)Setting of feedback resistance constant For both BD9305AFVM (step down) and BD9306AFVM (step up), please refer to the following formula for setting of feedback resistance. We recommend 10kΩ~330kΩ as the setting range. If a resistance below 10kΩ is set, a drop in voltage efficiency will be caused; if a resistance more than 330kΩ is set, the offset voltage becomes large because of the internal error amplifier’s input bias current of 0.05µA(Typ). Please set the maximum setting voltage of BD9306AFVM (step up) in such a way that Duty : (Vo - Vcc) / Vo is less than 70%. Reference Voltage 1.25V Vo Vo ＝ R1 + R2 R2 x 1.25 R1 [V] FB R2 8 － ERR ＋ Fig.26 Feedback Resistance Setting www.rohm.com © 2009 ROHM Co., Ltd. All rights reserved. 8/14 2009.05 - Rev.A Technical Note BD9306AFVM, BD9305AFVM (5) Setting of oscillation frequency The angular wave oscillation frequency can be set by respectively connecting resistor and condenser to RT (1 pin) and CT (2 pins). The currents to charge and discharge the condenser of CT are determined by RT. Please refer to the following drawing for setting the RT’s resistor and the CT’s condenser. RT:5~50kΩ, CT:100~1000pF, and the frequency range of 100kHz~800kHz are recommended. Please pay attention to that, the switching will stop if your setting is off this range. Frequency [kHz] 10000 1000 Ta=25℃ VCC=12V CT=100pF CT=200pF CT=470pF CT=1000pF 100 10 1 10 100 RT [kΩ] Fig.27 Frequency Setting (6)Selection of input condenser For DC/DC converter, the condenser at the input side is also necessary because peak current is flowing between input and output. Therefore, we recommend the low ESR condenser with over 10μF and below 100mΩ as the input condenser. If a selected condenser is off this range, excessively large ripple voltage will overlaps with the input voltage, which may cause IC malfunction.However, this condition varies with negative overcurrent, input voltage, output voltage, inductor’s value, and switching frequency, so please be sure to do the margin check with actual devices. (7)Selection of output rectifier diode We recommend the Schottky barrier diode as the diode for rectification at the output stage of DC/DC converter. Please be careful to choose the maximum inductor current, the maximum output voltage and the power supply voltage. ＜step-down DC/DC＞ ＜ Diode’s rated current Maximum inductor current IOMAX ＋ ⊿IL 2 Power supply voltage ＜step-up DC/DC＞ Maximum inductor current VCC IINMAX ＋ ⊿IL 2 ＜ Diode’s rated voltage ＜ Diode’s rated current ＜ Diode’s rated voltage Maximum output voltage VOMAX Furthermore, each parameter has a deviation of 30%~40%, so please design in such a way that you have left a sufficient margin for deviation in your design. (8)Setting of Power FET If step-down DC/DC is configured by BD9305AFVM, Pch FET is necessary; if step-up DC/DC is configured by BD9306AFVM, Nch FET is necessary. Please pay attention to the following conditions when you choose. ＜step-down DC/DC＞ ＜ FET’s rated current Maximum inductor current IOMAX ＋ ⊿IL 2 Power supply voltage VCC Power supply voltage Gate capacity (※) ＜step-up DC/DC＞ Maximum inductor current Maximum output voltage Power supply voltage ＜ FET’s rated voltage VCC ＞ FET’s gate ON voltage ＜ 2000pF CGATE IINMAX ＋ ⊿IL 2 ＜ FET’s rated current VOMAX VCC ＜ ＞ FET’s rated voltage FET’s gate ON voltage ＜ 2000pF Gate capacity (※) CGATE Furthermore, each parameter has a deviation of 30%~40%, so please design in such a way that you have left a sufficient margin for deviation in your design. (※) If Gate capacity becomes large, the switch’s switching speed gets slow, which may cause generation of heat and breakdown, so please check thoroughly with actual devices. www.rohm.com © 2009 ROHM Co., Ltd. All rights reserved. 9/14 2009.05 - Rev.A Technical Note BD9306AFVM, BD9305AFVM (9) Phase compensation Phase Setting Method The following conditions are required in order to ensure the stability of the negative feedback circuit. Phase lag should be 150° or lower during gain 1 (0 dB) (phase margin of 30° or higher). Because DC/DC converter applications are sampled using the switching frequency, the overall GBW should be set to 1/10 the switching frequency or lower. The target application characteristics can be summarized as follows: Phase lag should be 150° or lower during gain 1 (0 dB) (phase margin of 30° or higher). The GBW at that time (i.e., the frequency of a 0-dB gain) is 1/10 of the switching frequency or below. In other words, because the response is determined by the GBW limitation, it is necessary to use higher switching frequencies to raise response. One way to maintain stability through phase compensation involves canceling the secondary phase lag (-180°) caused by LC resonance with a secondary phase advance (by inserting 2 phase advances). The GBW (i.e., the frequency with the gain set to 1) is determined by the phase compensation capacitance connected to the error amp. Increase the capacitance if a GBW reduction is required. (a) Standard integrator (low-pass filter) (b) Open loop characteristics of integrator (a) A ＋ COMP A Feedback R -20 dB/decade Gain [dB] GBW(b) 0 － FB F 0 C -90° Phase -90 [°] Phase margin -180° -180 Point (a) fa = Fig. 28 1 2πRCA [Hz] Point (b) fb = GBW = F Fig. 29 1 2πRC [Hz] The error amp performs phase compensation of types (a) and (b), making it act as a low-pass filter. For DC/DC converter applications, R refers to feedback resistors connected in parallel. From the LC resonance of output, the number of phase advances to be inserted is two. LC resonant frequency fp = Vo R1 R4 C1 － R2 ＋ A COMP 1 2π√LC [Hz] Phase advance fz1 = 1 2πC1R1 [Hz] Phase advance fz2 = 1 2πC2R3 [Hz] R3 C2 Fig. 30 Set a phase advancing frequency close to the LC resonant frequency for the purpose of canceling the LC resonance. (※ )If high-frequency noise is generated in the output, FB is affected through condenser C1. Therefore, please insert the resistor R4=1kΩ or so, which is in series with condenser C1. www.rohm.com © 2009 ROHM Co., Ltd. All rights reserved. 10/14 2009.05 - Rev.A Technical Note BD9306AFVM, BD9305AFVM Example of application ※We recommend the application circuit examples with confidence, but hope that you will thoroughly check the characteristics over again when putting them to use. When you change the external circuit constant and use, please make a decision to leave a sufficient margin after taking into consideration the deviation etc. of external components and ROHM IC, in terms of not only the static characteristic but also the transient characteristic. Moreover, please understand that our company can not confirm fully with regard to the patent right. ＜Master Slave Function＞ The master slave function, which is that the synchronous switching is possible by using these IC of BD9305AFVM / BD9306AFVM through their multi-connection, is mounted. The following drawing shows an example of connection circuit in which BD9305AFVM is connected on the master side and BD9306AFVM is connected on the slave side. CTL0 VCC GD ENB RT (Slave Side) GD ENB CT RT GND BD9306AFVM (Master Side) RT COMP FB GND VCC CTL2 BD9305AFVM CT CTL1 COMP FB VCC Vo2 CT Vo1 Fig.31 Master Slave Application Circuit In the above-mentioned circuit, BD9306AFVM, which is synchronized with the switching frequency determined by RT and CT of BD9305AFVM that is the master, operates.In addition, the ON/OFF of output can be controlled by connecting the switch to the COMP terminal. (Refer to the following table) Control signal correspondence table Output state Control signal Vo1 Vo2 CTL0 CTL1 CTL2 OFF OFF Low ＊ ＊ OFF ON High High Low ON OFF High Low High ON ON High Low Low ＊The same in either case of High / Low. Similarly in the case of connecting three or more than three, synchronization is possible by connecting the CT terminal of Master and the CT terminal of Slave www.rohm.com © 2009 ROHM Co., Ltd. All rights reserved. 11/14 2009.05 - Rev.A Technical Note BD9306AFVM, BD9305AFVM I/O Equivalent Circuit Diagram Fig.32 1.RT 4.GD VCC VCC VREF A A: 2.CT VCC(BD9305AFVM) GND(BD9306AFVM) 7.COMP VCC VCC VREF VREF 3.ENB 8.FB VCC VREF Fig. 32 www.rohm.com © 2009 ROHM Co., Ltd. All rights reserved. 12/14 2009.05 - Rev.A Technical Note BD9306AFVM, BD9305AFVM Notes for use 1) Absolute maximum ratings Use of the IC in excess of absolute maximum ratings such as the applied voltage or operating temperature range may result in IC damage. Assumptions should not be made regarding the state of the IC (short mode or open mode) when such damage is suffered. A physical safety measure such as a fuse should be implemented when use of the IC in a special mode where the absolute maximum ratings may be exceeded is anticipated. 2) GND potential Ensure a minimum GND pin potential in all operating conditions. 3) Setting of heat Use a thermal design that allows for a sufficient margin in light of the power dissipation (Pd) in actual operating conditions. 4) Pin short and mistake fitting Use caution when orienting and positioning the IC for mounting on printed circuit boards. Improper mounting may result in damage to the IC. Shorts between output pins or between output pins and the power supply and GND pins caused by the presence of a foreign object may result in damage to the IC. 5) Actions in strong magnetic field Use caution when using the IC in the presence of a strong magnetic field as doing so may cause the IC to malfunction. 6) Testing on application boards When testing the IC on an application board, connecting a capacitor to a pin with low impedance subjects the IC to stress. Always discharge capacitors after each process or step. Ground the IC during assembly steps as an antistatic measure, and use similar caution when transporting or storing the IC. Always turn the IC's power supply off before connecting it to or removing it from a jig or fixture during the inspection process. 7) Ground wiring patterns When using both small signal and large current GND patterns, it is recommended to isolate the two ground patterns, placing a single ground point at the application's reference point so that the pattern wiring resistance and voltage variations caused by large currents do not cause variations in the small signal ground voltage. Be careful not to change the GND wiring patterns of any external components. 8) Regarding input pin of the IC This monolithic IC contains P+ isolation and P substrate layers between adjacent elements in order to keep them isolated. P/N junctions are formed at the intersection of these P layers with the N layers of other elements to create a variety of parasitic elements.For example, when the resistors and transistors are connected to the pins shown as follows, a parasitic diode or a transistor operates by inverting the pin voltage and GND voltage. The formation of parasitic elements as a result of the relationships of the potentials of different pins is an inevitable result of the IC's architecture. The operation of parasitic elements can cause interference with circuit operation as well as IC malfunction and damage. For these reasons, it is necessary to use caution so that the IC is not used in a way that will trigger the operation of parasitic elements such as by the application of voltages lower than the GND (P substrate) voltage to input and output pins. Example of a SimpleMonolithic IC Architecture Resistor Transistor (NPN) B C B E ～ ～ ～ ～ (Pin B) (Pin B) ～ ～ (Pin A) GND N N P P P+ N N N N (Pin A) P substrate Parasitic elements GND Parasitic elements P+ ～ ～ P+ Parasitic elements E GND N P P+ C Parasitic elements GND GND Fig. 33 9) Overcurrent protection circuits An overcurrent protection circuit designed according to the output current is incorporated for the prevention of IC damage that may result in the event of load shorting. This protection circuit is effective in preventing damage due to sudden and unexpected accidents. However, the IC should not be used in applications characterized by the continuous operation or transitioning of the protection circuits. At the time of thermal designing, keep in mind that the current capacity has negative characteristics to temperatures. www.rohm.com © 2009 ROHM Co., Ltd. All rights reserved. 13/14 2009.05 - Rev.A Technical Note BD9306AFVM, BD9305AFVM Ordering part number B D Part No. 9 3 0 6 A F Part No. 9306A 9305A V M Package FVM: MSOP8 - T R Packaging and forming specification TR: Embossed tape and reel MSOP8 <Tape and Reel information> 2.8±0.1 4.0±0.2 8 7 6 5 0.6±0.2 +6° 4° −4° 0.29±0.15 2.9±0.1 (MAX 3.25 include BURR) Tape Embossed carrier tape Quantity 3000pcs Direction of feed TR The direction is the 1pin of product is at the upper right when you hold ( reel on the left hand and you pull out the tape on the right hand ) 1 2 3 4 1PIN MARK 1pin +0.05 0.145 –0.03 0.475 0.08±0.05 0.75±0.05 0.9MAX S +0.05 0.22 –0.04 0.08 S Direction of feed 0.65 (Unit : mm) www.rohm.com © 2009 ROHM Co., Ltd. All rights reserved. Reel 14/14 ∗ Order quantity needs to be multiple of the minimum quantity. 2009.05 - Rev.A Notice Notes No copying or reproduction of this document, in part or in whole, is permitted without the consent of ROHM Co.,Ltd. The content specified herein is subject to change for improvement without notice. The content specified herein is for the purpose of introducing ROHM's products (hereinafter "Products"). If you wish to use any such Product, please be sure to refer to the specifications, which can be obtained from ROHM upon request. Examples of application circuits, circuit constants and any other information contained herein illustrate the standard usage and operations of the Products. The peripheral conditions must be taken into account when designing circuits for mass production. Great care was taken in ensuring the accuracy of the information specified in this document. However, should you incur any damage arising from any inaccuracy or misprint of such information, ROHM shall bear no responsibility for such damage. The technical information specified herein is intended only to show the typical functions of and examples of application circuits for the Products. ROHM does not grant you, explicitly or implicitly, any license to use or exercise intellectual property or other rights held by ROHM and other parties. ROHM shall bear no responsibility whatsoever for any dispute arising from the use of such technical information. The Products specified in this document are intended to be used with general-use electronic equipment or devices (such as audio visual equipment, office-automation equipment, communication devices, electronic appliances and amusement devices). The Products specified in this document are not designed to be radiation tolerant. While ROHM always makes efforts to enhance the quality and reliability of its Products, a Product may fail or malfunction for a variety of reasons. Please be sure to implement in your equipment using the Products safety measures to guard against the possibility of physical injury, fire or any other damage caused in the event of the failure of any Product, such as derating, redundancy, fire control and fail-safe designs. ROHM shall bear no responsibility whatsoever for your use of any Product outside of the prescribed scope or not in accordance with the instruction manual. The Products are not designed or manufactured to be used with any equipment, device or system which requires an extremely high level of reliability the failure or malfunction of which may result in a direct threat to human life or create a risk of human injury (such as a medical instrument, transportation equipment, aerospace machinery, nuclear-reactor controller, fuel-controller or other safety device). ROHM shall bear no responsibility in any way for use of any of the Products for the above special purposes. If a Product is intended to be used for any such special purpose, please contact a ROHM sales representative before purchasing. If you intend to export or ship overseas any Product or technology specified herein that may be controlled under the Foreign Exchange and the Foreign Trade Law, you will be required to obtain a license or permit under the Law. Thank you for your accessing to ROHM product informations. More detail product informations and catalogs are available, please contact us. ROHM Customer Support System http://www.rohm.com/contact/ www.rohm.com © 2009 ROHM Co., Ltd. All rights reserved. R0039A