Datasheet 4.0V to 5.5V, 0.8A 1ch Synchronous Buck Converter with Integrated FET BD8966FVM General Description Key Specifications The BD8966FVM is ROHM’s high efficiency step-down switching regulator designed to produce a voltage as low as 1V from a supply voltage of 5V. It offers high efficiency by using synchronous switches and provides fast transient response to sudden load changes by implementing current mode control. Features Fast Transient Response because of Current Mode PWM Control System High Efficiency for All Load Ranges with Synchronous Rectifier (Nch/Pch FET) Soft-Start Function Thermal Shutdown and UVLO Functions Short-Circuit Current Protection with Time Delay Function Shutdown Function Input Voltage Range: Output Voltage Range: Output Current: Switching Frequency: Pch FET ON-Resistance: Nch FET ON-Resistance: Standby Current: Operating Temperature Range: 4.0V to 5.5V 1.0V to 2.5V 0.8A (Max) 1MHz (Typ) 350mΩ (Typ) 350mΩ (Typ) 0μA (Typ) -25°C to +85°C W(Typ) x D(Typ) x H(Max) Package Applications Power Supply for LSI including DSP, Microcomputer and ASIC MSOP8 2.90 mm x 4.00 mm x 0.90 mm Typical Application Circuit VCC CIN L VCC,PVCC EN VOUT SW CO ADJ R2 ITH GND,PGND RITH R1 CITH Figure 1. Typical Application Circuit ○Product structure：Silicon monolithic integrated circuit www.rohm.com © 2012 ROHM Co., Ltd. All rights reserved. TSZ22111･14･001 ○This product has no designed protection against radioactive rays 1/21 TSZ02201-0J3J0AJ00060-1-2 22.Jan.2015 Rev.003 Datasheet BD8966FVM Pin Configuration (TOP VIEW) VCC PVCC SW PGND Figure 2. Pin Configuration Pin Description Pin No. 1 2 3 4 5 6 7 8 Pin Name ADJ ITH EN GND PGND SW PVCC VCC Function Output voltage detection pin GmAmp output pin/connected to phase compensation capacitor Enable pin (Active high) Ground pin Power switch ground pin Power switch node Power switch supply pin Power supply input pin Block Diagram VCC EN 3 VCC 8 VREF Input 7 PVCC Current Comp. R Gm Amp Q Current Sense/ Protect S SLOPE VCC CLK Output 6 OSC SW Driver Logic UVLO Soft Start + 5 TSD PGND 4 GND 1 2 ADJ ITH Figure 3. Block Diagram www.rohm.com © 2012 ROHM Co., Ltd. All rights reserved. TSZ22111･15･001 2/21 TSZ02201-0J3J0AJ00060-1-2 22.Jan.2015 Rev.003 Datasheet BD8966FVM Absolute Maximum Ratings Parameter VCC Voltage PVCC Voltage EN Voltage SW, ITH Voltage Symbol Rating Unit (Note 1) V PVCC -0.3 to +7 (Note 1) V VEN -0.3 to +7 V VCC -0.3 to +7 VSW, VITH -0.3 to +7 V Power Dissipation 1 Pd1 0.38 (Note 2) W Power Dissipation 2 Pd2 0.58 (Note 3) W Operating Temperature Range Topr -25 to +85 °C Storage Temperature Range Tstg -55 to +150 °C Tjmax +150 °C Maximum Junction Temperature (Note 1) Pd should not be exceeded. (Note 2) Reduce by 3.1mW/°C for temperatures above Ta=25°C. (Note 3) Reduce by 4.7mW/°C for temperatures above Ta=25°C, Mounted on 1 layer 70mmx70mmx1.6mm Glass Epoxy PCB. Caution: 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. Recommended Operating Conditions (Ta=25°C) Parameter VCC Voltage PVCC Voltage EN Voltage SW Average Output Current Output Voltage Setting Range (Note 4) Symbol (Note 4) Limit Min Typ Max Unit 4.0 5.0 5.5 V PVCC (Note 4) 4.0 5.0 5.5 V - VCC V 0.8 A 2.5 V VCC VEN 0 ISW (Note 4) - VOUT 1.0 - Pd should not be exceeded. Electrical Characteristics (Ta=25°C, VCC=5V, VEN=VCC, R1=20kΩ, R2=10kΩ unless otherwise specified.) Parameter Standby Current Bias Current EN Low Voltage EN High Voltage EN Input Current Oscillation Frequency Pch FET ON-Resistance Nch FET ON-Resistance ADJ Voltage ITH Sink Current ITH Source Current UVLO Threshold Voltage UVLO Release Voltage Soft-Start Time Timer Latch Time www.rohm.com © 2012 ROHM Co., Ltd. All rights reserved. TSZ22111･15･001 Symbol ISTB ICC VENL VENH IEN fOSC RONP RONN VADJ ITHSI ITHSO VUVLO1 VUVLO2 tSS tLATCH Limit Typ 0 250 GND VCC 1 1 350 250 0.80 20 20 3.40 3.50 3 2 Min 2.0 0.8 0.78 10 10 3.20 3.25 1.5 0.5 3/21 Max 10 450 0.8 10 1.2 600 500 0.82 3.6 3.80 6 3 Unit µA µA V V µA MHz mΩ mΩ V µA µA V V ms ms Conditions EN=GND Standby mode Active mode VEN=5V PVCC=5V PVCC=5V VADJ=H VADJ=L VCC=4V to 0V VCC=0V to 4V VADJ=H SCP/TSD operated TSZ02201-0J3J0AJ00060-1-2 22.Jan.2015 Rev.003 Datasheet BD8966FVM [VOUT=1.8V] Ta=25°C IO=0A [VOUT=1.8V] Output Voltage: VOUT [V] Output Voltage: VOUT [V] Typical Performance Curves Input Voltage: VCC [V] EN Voltage: VEN [V] Figure 5. Output Voltage vs EN Voltage Figure 4. Output Voltage vs Input Voltage [VOUT=1.8V] Output Voltage: VOUT [V] Output Voltage: VOUT [V] [VOUT=1.8V] Output Current: IOUT [A] Temperature: Ta [°C] Figure 6. Output Voltage vs Output Current www.rohm.com © 2012 ROHM Co., Ltd. All rights reserved. TSZ22111･15･001 Figure 7. Output Voltage vs Temperature 4/21 TSZ02201-0J3J0AJ00060-1-2 22.Jan.2015 Rev.003 Datasheet BD8966FVM Typical Performance Curves – continued VCC=5V Efficiency: η [%] Frequency: fOSC [MHz] [VOUT=1.8V] Output Current: IOUT [mA] Temperature: Ta [°C] Figure 9. Frequency vs Temperature EN Voltage: VEN [V] ON-Resistance: RON [Ω] Figure 8. Efficiency vs Output Current Temperature: Ta [°C] Temperature: Ta [°C] Figure 10. ON-Resistance vs Temperature www.rohm.com © 2012 ROHM Co., Ltd. All rights reserved. TSZ22111･15･001 Figure 11. EN Voltage vs Temperature 5/21 TSZ02201-0J3J0AJ00060-1-2 22.Jan.2015 Rev.003 Datasheet BD8966FVM Frequency: fOSC [MHz] Circuit Current: ICC [µA] Typical Performance Curves – continued Input Voltage: VCC [V] Temperature: Ta [°C] Figure 12. Circuit Current vs Temperature www.rohm.com © 2012 ROHM Co., Ltd. All rights reserved. TSZ22111･15･001 Figure 13. Frequency vs Input Current 6/21 TSZ02201-0J3J0AJ00060-1-2 22.Jan.2015 Rev.003 Datasheet BD8966FVM Typical Waveforms [VOUT=1.8V] [PWM VCC=PVCC =EN [VOUT=1.8V] SW VOUT VOUT VCC=5V Ta=25°C IO=0A VCC=5V Ta=25°C Figure 14. Soft-Start Waveform Figure 15. SW Waveform [VOUT=1.8V] [VOUT=1.8V] VOUT VOUT 98mV 90mV IOUT IOUT VCC=5VT Ta=25°C VCC=5VT Ta=25°C Figure 16. Transient Response (IO=100mA to 600mA, 10µs) www.rohm.com © 2012 ROHM Co., Ltd. All rights reserved. TSZ22111･15･001 Figure 17. Transient Response (IO=600mA to100mA, 10µs) 7/21 TSZ02201-0J3J0AJ00060-1-2 22.Jan.2015 Rev.003 Datasheet BD8966FVM Application Information 1. Operation BD8966FVM is a synchronous step-down switching regulator that achieves a fast transient response by employing current mode PWM control system. (1) Synchronous Rectifier Integrated synchronous rectification using two MOSFETS reduces power dissipation and increases efficiency when compared to converters using external diodes. Internal shoot-through current limiting circuit further reduces power dissipation. (2) Current Mode PWM Control The PWM control signal of this IC depends on two feedback loops, the voltage feedback and the inductor current feedback. (a) PWM (Pulse Width Modulation) Control The clock signal coming from OSC has a frequency of 1Mhz. When OSC sets the RS latch, the P-Channel MOSFET is turned on and the N-channel MOSFET is turned OFF. The opposite happens when the current comparator (Current Comp) resets the RS latch i.e. the P-Channel MOSFET is turned OFF and the N-Channel MOSFET is turned on. Current Comp’s output is a comparison of two signals, the current feedback control signal “SENSE” which is a voltage proportional to the current IL, and the voltage feedback control signal, FB. SENSE Current Comp RESET VOUT Level Shift R Q FB SET Gm Amp RITH S IL Driver Logic VOUT SW Load OSC Figure 18. Diagram of Current Mode PWM Control PVCC Current Comp SENSE FB SET GND RESET GND SW GND IL IL(AVE) VOUT VOUT(AVE) Figure 19. PWM Switching Timing Diagram www.rohm.com © 2012 ROHM Co., Ltd. All rights reserved. TSZ22111･15･001 8/21 TSZ02201-0J3J0AJ00060-1-2 22.Jan.2015 Rev.003 Datasheet BD8966FVM 2. Description of Functions (1) Soft-Start Function During start-up, the soft-start circuit gradually establishes the output voltage to limit the input current. This prevents the overshoot in the output voltage and inrush current. (2) Shutdown Function When EN terminal is “Low”, the device operates in Standby Mode, and all functional blocks such as the reference voltage circuit, internal oscillator, and drivers, are turned OFF. Circuit current during standby is 0μA (Typ). (3) UVLO Function The UVLO circuit detects whether the supplied input voltage is sufficient to obtain the output voltage of this IC. The UVLO threshold has a hysteresis of 100mV (Typ) to prevent the output from chattering. Hysteresis 100mV VCC EN VOUT tss tss tss Soft start Standby mode Standby mode Operating mode Operating mode UVLO UVLO Standby mode Operating mode EN Standby mode UVLO Figure 20. Soft Start, Shutdown, UVLO Timing Diagram (4) Short-Circuit Current Protection with Time Delay Function To protect the IC from breakdown, the short-circuit protection turns the output OFF when the internal current limiter is activated continuously for at least 1 ms. The output that is held OFF may be turned ON again by restarting EN or by resetting UVLO. EN Output OFF Latch SCP Voltage VOUT IL Limit IL t1<tLATCH t2=tLATCH Operating mode Output OFF Operating mode Output OFF EN Timer Latch EN Figure 21. Short-Circuit Protection with Time Delay Diagram www.rohm.com © 2012 ROHM Co., Ltd. All rights reserved. TSZ22111･15･001 9/21 TSZ02201-0J3J0AJ00060-1-2 22.Jan.2015 Rev.003 Datasheet BD8966FVM 3. Information on Advantages Advantage 1: Offers fast transient response by using current mode control system. Conventional product (Load response IO=0.1A to 0.6A) VOUT BD8966FVM (Load response IO=0.1A to 0.6A) VOUT 110mV IOUT 90mV IOUT Voltage drop due to sudden change in load was reduced. Figure 22. Comparison of Transient Response Advantage 2: Offers high efficiency with synchronous rectifier For heavier load: This IC utilizes the synchronous rectifying mode and uses low ON-Resistance power MOSFET. 【VOUT=1.8V】 Efficiency: η [%] EFFICIENCY: η[%] 100 90 ON-Resistance of P-Channel MOSFET: 350mΩ(Typ) ON-Resistance of N-Channel MOSFET: 250mΩ(Typ) 80 70 60 50 40 30 VCC=5V Ta=25°C 20 10 0 1 10 100 1000 OUTPUT CURRENT:IOUT[mA] Output Current: IOUT [mA] Figure 23 Advantage 3:・Supplied in smaller package due to small-sized power MOSFETs. ・Required Output capacitor CO for current mode control:10μF ceramic capacitor ・Required Inductance L for the operating frequency of 1 MHz: 4.7μH inductor Reduces the mounting area requirement VCC 15mm CIN CIN RITH DC/DC Convertor Controller L RITH L VOUT 10mm CITH CO CO CITH Figure 24. Example Application www.rohm.com © 2012 ROHM Co., Ltd. All rights reserved. TSZ22111･15･001 10/21 TSZ02201-0J3J0AJ00060-1-2 22.Jan.2015 Rev.003 Datasheet BD8966FVM 4. Switching Regulator Efficiency Efficiency η may be expressed by the equation shown below: VOUT I OUT P POUT 100 OUT 100 100 VIN I IN PIN POUT Pd % Efficiency may be improved by reducing the switching regulator power dissipation factors Pdα as follows: Dissipation factors: (1) ON-Resistance Dissipation of Inductor and FET : Pd(I2R) Pd I 2 R I OUT 2 RCOIL RON Where: RCOIL is the DC resistance of inductor RON is the ON-Resistance of FET IOUT is the OUTPUT current. (2) Gate Charge/Discharge Dissipation: Pd(Gate) Pd Gate C gs f V 2 Where: Cgs is the gate capacitance of FET f is the switching frequency V is the gate driving voltage of FET (3) Switching Dissipation : Pd(SW) Pd SW V IN 2 C RSS I OUT f I DRIVE Where: CRSS is the reverse transfer capacitance of FET IDRIVE is the peak current of gate. (4) ESR Dissipation of Capacitor: Pd(ESR) Pd ESR I RMS 2 ESR Where: IRMS is the ripple current of capacitor ESR is the equivalent series resistance. (5) Operating Current Dissipation of IC: Pd(IC) Pd IC V IN I CC Where: ICC is the circuit current. www.rohm.com © 2012 ROHM Co., Ltd. All rights reserved. TSZ22111･15･001 11/21 TSZ02201-0J3J0AJ00060-1-2 22.Jan.2015 Rev.003 Datasheet BD8966FVM 5. Consideration on Permissible Dissipation and Heat Generation Since 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. This is because the conduction losses are most significant among other dissipation factors mentioned above such as gate charge/discharge dissipation and switching dissipation. Power Dissipation: Pd [mW] 1000 ①mounted on glass epoxy PCB θj-a=212.8°C/W ②using an IC alone θj-a=322.6°C/W 800 P I OUT 2 RCOIL RON RON D RONP 1 D RONN ①587.4mW 600 ②387.5mW 400 Where: D is the ON duty (=VOUT/VCC) RCOIL is the DC resistance of coil RONP is the ON-Resistance of P-Channel MOS FET RONN is the ON-Resistance of N-Channel MOS FET IOUT is the Output current 200 0 75 85 100 25 50 125 Ambient Temperature :Ta[°C] 0 150 Figure 25 Thermal Derating Curve (MSOP8) If VCC=5V, VOUT=1.5V, RCOIL=0.15Ω, RONP=0.35Ω, RONN=0.25Ω IOUT=0.8A, for example, D=VOUT/VCC=1.5/5=0.3 RON=0.3x0.35+(1-0.3)x0.25 =0.105+0.175 =0.28[Ω] P=0.82x(0.15+0.28) ≈ 275.2[mW] Since RONP is greater than RONN in this IC, the dissipation increases as the ON duty becomes greater. Taking into consideration the dissipation shown above, thermal design must be carried out with allowable sufficient margin. 6. Selection of Components Externally Connected (1) Selection of Inductor (L) IL ∆IL The inductance significantly depends on output ripple current. As shown in equation (1), the ripple current decreases as the inductor and/or switching frequency increases. IL VOUT L CO Figure 26. Output Ripple Current VCC VOUT VOUT ・・・(1) A L VCC f Appropriate ripple current at output should be ±30% of the maximum output current. A IL 0.3 I OUTMax ・・・(2) IL VCC L VCC VOUT VOUT I L VCC f H ・・・(3) Where: ΔIL is the Output ripple current, and f is the Switching frequency Note: Current exceeding the current rating of the inductor results in magnetic saturation of the inductor, which decreases efficiency. The inductor must be selected by allowing sufficient margin with which the peak current may not exceed its current rating. If VCC=5V, VOUT=1.5V, f=1MHz, ΔIL=0.3x0.8A=0.24A, for example, 5 1.5 1.5 4.375 4.7 H L 0.24 5 1M Note: Select an inductor with low resistance component (such as DCR and ACR) to minimize dissipation in the inductor for better efficiency. www.rohm.com © 2012 ROHM Co., Ltd. All rights reserved. TSZ22111･15･001 12/21 TSZ02201-0J3J0AJ00060-1-2 22.Jan.2015 Rev.003 Datasheet BD8966FVM (2) Selection of Output Capacitor (CO) Output capacitor should be selected with the consideration on the stability region and the equivalent series resistance required to minimize ripple voltage. Output ripple voltage is determined by the equation (4): VCC L V ・・・(4) V OUT I L ESR VOUT Where: ΔIL is the Output Ripple Current, and ESR is the Equivalent series resistance of output capacitor ESR CO Note: Rating of the capacitor should be determined by allowing sufficient margin against output voltage. Less ESR allows reduction in output ripple voltage. Figure 27. Output Capacitor Since the output rise time is designed to fall within the soft-start time, the capacitance of output capacitor should be determined by the requirements of equation (5): CO t SS I LIMIT I OUT VOUT ・・・(5) Where: tSS: Soft-Start time ILIMIT: Over current detection level, 2A(Typ) In case of BD8966FVM, for instance, and if VOUT=1.5V, IOUT=0.8A, and tSS=1ms, CO 1m (2 0.8) 800 1.5 F Rating of the capacitor should be determined to allow sufficient margin against output voltage. A 10μF to 100μF ceramic capacitor is recommended. (3) Selection of input capacitor (CIN) VCC Input capacitor must have a low ESR capacitor with capacitance sufficient to cope with high ripple current to prevent high transient voltage. The ripple current IRMS is given by the equation (6): CIN VOUT L Co I RMS I OUT VOUT VCC VOUT VCC A・・・(6) < Worst case > IRMSMax When VCC is twice the VOUT , IRMS Figure 28. Input Capacitor IOUT 2 If VCC=5.0V, VOUT=1.5V, and IOUTMax = 0.8A I RMS 0.8 1.55 1.5 0.37 5 ARMS A low ESR 10µF/10V ceramic capacitor is recommended to reduce ESR dissipation of input capacitor for better efficiency. www.rohm.com © 2012 ROHM Co., Ltd. All rights reserved. TSZ22111･15･001 13/21 TSZ02201-0J3J0AJ00060-1-2 22.Jan.2015 Rev.003 Datasheet BD8966FVM (4) Calculating RITH, CITH for phase compensation Since the Current Mode Control is designed to limit the inductor current, a pole (phase lag) appears in the low frequency area due to a CR filter consisting of an 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. Therefore, 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) fp A Gain [dB] fp(Max) f Z ESR 0 fZ(ESR) IOUTMin Phase [deg] IOUTMax Figure 29. Open Loop Gain Characteristics A 1 2 ESR CO Pole at power amplifier When the output current decreases, the load resistance RO increases and the pole frequency decreases. 0 -90 fpMin 1 2 ROMax CO Hz with lighter load fpMax 1 Hz with heavier load 2 ROMin CO fZ(Amp) Gain [dB] Zero at power amplifier Increasing capacitance of the output capacitor lowers the pole frequency while the zero frequency does not change. (This is because when the capacitance is doubled, the capacitor ESR is reduced to half.) 0 0 Phase [deg] 1 2 RO C O -90 f Z Amp Figure 30. Error Amp Phase Compensation Characteristics VCC CIN VOUT EN VCC,PVCC SW ESR VOUT ITH L GND,PGND 1 2 RITH C ITH VOUT RO CO RITH CITH Figure 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. f Z Amp f P Min 1 1 2 RITH C ITH 2 ROMax CO (5) Setting the output voltage The output voltage VOUT is determined by the equation (7): L VOUT R2 / R1 1 V ADJ ・・・(7) Output SW Where: VADJ is the Voltage at ADJ terminal (0.8V Typ) The required output voltage may be determined by adjusting R1 and R2. ADJ Co R2 R1 Adjustable output voltage range: 1.0V to 2.5V Figure 32. Determination of Output Voltage Use 1kΩ to 100kΩ resistor for R1. If a resistor higher than 100kΩ is used, check the assembled set carefully for ripple voltage etc. www.rohm.com © 2012 ROHM Co., Ltd. All rights reserved. TSZ22111･15･001 14/21 TSZ02201-0J3J0AJ00060-1-2 22.Jan.2015 Rev.003 Datasheet BD8966FVM 7. BD8966FVM Cautions on PC Board Layout RFB1 1 ADJ VCC 8 2 ITH PVCC 7 3 EN SW 6 4 GND PGND 5 RFB2 RITH VCC CIN EN ① L VOUT CITH ③ CO ② GND Figure 33. Layout Diagram ① For the sections drawn with heavy line, use thick conductor pattern as short as possible. ② Layout the input ceramic capacitor CIN closer to the pins PVCC and PGND, and the output capacitor CO closer to the pin PGND. ③ Layout CITH and RITH between the pins ITH and GND as near as possible with least necessary wiring. 8. Recommended Components Lists on Above Application Symbol Part Value L CIN CO CITH RITH Coil Ceramic capacitor Ceramic capacitor Ceramic capacitor Resistance 4.7µH 10µF 10µF 750pF VOUT=1.0V VOUT=1.2V VOUT=1.5V VOUT=1.8V VOUT=2.5V 18kΩ 22kΩ 22kΩ 27kΩ 36kΩ Manufacturer Sumida TDK Kyocera Kyocera murata ROHM ROHM ROHM ROHM ROHM Series CMD6D11B VLF5014AT-4R7M1R1 CM316X5R106K10A CM316X5R106K10A GRM18series MCR10 1802 MCR10 2202 MCR10 2202 MCR10 2702 MCR10 3602 Note: The parts list presented above is an example of recommended parts. Although the parts are standard, 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 significant and may affect the system, a low pass filter should be inserted between the VCC and PVCC pins, and a schottky barrier diode established between the SW and PGND pins. www.rohm.com © 2012 ROHM Co., Ltd. All rights reserved. TSZ22111･15･001 15/21 TSZ02201-0J3J0AJ00060-1-2 22.Jan.2015 Rev.003 Datasheet BD8966FVM I/O Equivalent Circuit ・EN Pin PVCC ・SW Pin PVCC PVCC EN SW ・ADJ Pin ・ITH Pin VCC VCC 10kΩ ITH ADJ Figure 34. I/O Equivalent Circuit www.rohm.com © 2012 ROHM Co., Ltd. All rights reserved. TSZ22111･15･001 16/21 TSZ02201-0J3J0AJ00060-1-2 22.Jan.2015 Rev.003 Datasheet BD8966FVM Operational Notes 1. Reverse Connection of Power Supply Connecting the power supply in reverse polarity can damage the IC. Take precautions against reverse polarity when connecting the power supply, such as mounting an external diode between the power supply and the IC’s power supply pins. 2. Power Supply Lines Design the PCB layout pattern to provide low impedance supply lines. Separate the ground and supply lines of the digital and analog blocks to prevent noise in the ground and supply lines of the digital block from affecting the analog block. Furthermore, connect a capacitor to ground at all power supply pins. Consider the effect of temperature and aging on the capacitance value when using electrolytic capacitors. 3. Ground Voltage Ensure that no pins are at a voltage below that of the ground pin at any time, even during transient condition. 4. Ground Wiring Pattern When using both small-signal and large-current ground traces, the two ground traces should be routed separately but connected to a single ground at the reference point of the application board to avoid fluctuations in the small-signal ground caused by large currents. Also ensure that the ground traces of external components do not cause variations on the ground voltage. The ground lines must be as short and thick as possible to reduce line impedance. 5. Thermal Consideration Should by any chance the power dissipation rating be exceeded the rise in temperature of the chip may result in deterioration of the properties of the chip. In case of exceeding this absolute maximum rating, increase the board size and copper area to prevent exceeding the Pd rating. 6. Recommended Operating Conditions These conditions represent a range within which the expected characteristics of the IC can be approximately obtained. The electrical characteristics are guaranteed under the conditions of each parameter. 7. Inrush Current When power is first supplied to the IC, it is possible that the internal logic may be unstable and inrush current may flow instantaneously due to the internal powering sequence and delays, especially if the IC has more than one power supply. Therefore, give special consideration to power coupling capacitance, power wiring, width of ground wiring, and routing of connections. 8. Operation Under Strong Electromagnetic Field Operating the IC in the presence of a strong electromagnetic field may cause the IC to malfunction. 9. Testing on Application Boards When testing the IC on an application board, connecting a capacitor directly to a low-impedance output pin may subject the IC to stress. Always discharge capacitors completely after each process or step. The IC’s power supply should always be turned off completely before connecting or removing it from the test setup during the inspection process. To prevent damage from static discharge, ground the IC during assembly and use similar precautions during transport and storage. 10. Inter-pin Short and Mounting Errors Ensure that the direction and position are correct when mounting the IC on the PCB. Incorrect mounting may result in damaging the IC. Avoid nearby pins being shorted to each other especially to ground, power supply and output pin. Inter-pin shorts could be due to many reasons such as metal particles, water droplets (in very humid environment) and unintentional solder bridge deposited in between pins during assembly to name a few. www.rohm.com © 2012 ROHM Co., Ltd. All rights reserved. TSZ22111･15･001 17/21 TSZ02201-0J3J0AJ00060-1-2 22.Jan.2015 Rev.003 Datasheet BD8966FVM Operational Notes – continued 11. Unused Input Pins Input pins of an IC are often connected to the gate of a MOS transistor. The gate has extremely high impedance and extremely low capacitance. If left unconnected, the electric field from the outside can easily charge it. The small charge acquired in this way is enough to produce a significant effect on the conduction through the transistor and cause unexpected operation of the IC. So unless otherwise specified, unused input pins should be connected to the power supply or ground line. 12. Regarding the 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 the P layers with the N layers of other elements, creating a parasitic diode or transistor. For example (refer to figure below): When GND > Pin A and GND > Pin B, the P-N junction operates as a parasitic diode. When GND > Pin B, the P-N junction operates as a parasitic transistor. Parasitic diodes inevitably occur in the structure of the IC. The operation of parasitic diodes can result in mutual interference among circuits, operational faults, or physical damage. Therefore, conditions that cause these diodes to operate, such as applying a voltage lower than the GND voltage to an input pin (and thus to the P substrate) should be avoided. Figure 35. Example of monolithic IC structure 13. Thermal Shutdown Circuit(TSD) This IC has a built-in thermal shutdown circuit that prevents heat damage to the IC. Normal operation should always be within the IC’s power dissipation rating. If however the rating is exceeded for a continued period, the junction temperature (Tj) will rise which will activate the TSD circuit that will turn OFF all output pins. When the Tj falls below the TSD threshold, the circuits are automatically restored to normal operation. Note that the TSD circuit operates in a situation that exceeds the absolute maximum ratings and therefore, under no circumstances, should the TSD circuit be used in a set design or for any purpose other than protecting the IC from heat damage. 14. Selection of Inductor It is recommended to use an inductor with a series resistance element (DCR) 0.1Ω or less. Especially, 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. www.rohm.com © 2012 ROHM Co., Ltd. All rights reserved. TSZ22111･15･001 18/21 TSZ02201-0J3J0AJ00060-1-2 22.Jan.2015 Rev.003 Datasheet BD8966FVM Ordering Information B D 8 9 6 Part Number 6 F V M Package FVM: MSOP8 TR Packaging and forming specification TR: Embossed tape and reel Marking Diagram MSOP8 (TOP VIEW) Part Number Marking D 6 8 9 6 LOT Number 1PIN MARK www.rohm.com © 2012 ROHM Co., Ltd. All rights reserved. TSZ22111･15･001 19/21 TSZ02201-0J3J0AJ00060-1-2 22.Jan.2015 Rev.003 Datasheet BD8966FVM Physical Dimension Tape and Reel information Package Name MSOP8 <Tape and Reel information> 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 ) 1pin Direction of feed Reel www.rohm.com © 2012 ROHM Co., Ltd. All rights reserved. TSZ22111･15･001 ∗ Order quantity needs to be multiple of the minimum quantity. 20/21 TSZ02201-0J3J0AJ00060-1-2 22.Jan.2015 Rev.003 Datasheet BD8966FVM Revision History Date 02.Mar.2012 02.Oct.2014 22.Jan.2015 Revision 001 002 003 Changes New Release Applied the ROHM Standard Style and improved understandability. Modify Page15 Figure 33. Layout Diagram www.rohm.com © 2012 ROHM Co., Ltd. All rights reserved. TSZ22111･15･001 21/21 TSZ02201-0J3J0AJ00060-1-2 22.Jan.2015 Rev.003 Datasheet 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) , transport intend to use our Products in devices requiring extremely high reliability (such as medical equipment 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. If you intend to use our Products under any special or extraordinary environments or conditions (as exemplified below), your independent verification and confirmation of product performance, reliability, etc, prior to use, must be necessary: [a] Use of our Products in any types of liquid, including water, oils, chemicals, and organic solvents [b] Use of our Products outdoors or in places where the Products are exposed to direct sunlight or dust [c] Use of our Products in places where the Products are exposed to sea wind or corrosive gases, including Cl2, H2S, NH3, SO2, and NO2 [d] Use of our Products in places where the Products are exposed to static electricity or electromagnetic waves [e] Use of our Products in proximity to heat-producing components, plastic cords, or other flammable items [f] Sealing or coating our Products with resin or other coating materials [g] Use of our Products without cleaning residue of flux (even if you use no-clean type fluxes, cleaning residue of flux is recommended); or Washing our Products by using water or water-soluble cleaning agents for cleaning residue after soldering [h] Use of the Products in places subject to dew condensation 4. 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 (Pd) depending on Ambient temperature (Ta). When used in sealed area, confirm the actual ambient 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-GE © 2013 ROHM Co., Ltd. All rights reserved. Rev.004 Datasheet 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. 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 places where: [a] the Products are exposed to sea winds or corrosive gases, including Cl2, H2S, NH3, SO2, and NO2 [b] the temperature or humidity exceeds those recommended by ROHM [c] the Products are exposed to direct sunshine or condensation [d] the Products are exposed to 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 the recommended storage time period. 3. Store / transport cartons in the correct direction, which is indicated on a carton with 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 humidity barrier bag. Baking is required before using Products of which storage time is exceeding the recommended storage time period. Precaution for Product Label QR code printed on ROHM Products label is for ROHM’s internal use only. Precaution for Disposition When disposing Products please dispose them properly using an authorized industry waste company. Precaution for Foreign Exchange and Foreign Trade act Since our Products might fall under controlled goods prescribed by the applicable foreign exchange and foreign trade act, please consult with ROHM representative in case of export. Precaution Regarding Intellectual Property Rights 1. 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. ROHM shall not be in any way responsible or liable for infringement of any intellectual property rights or other damages arising from use of such information or data.: 2. 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 information contained in this document. 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-GE © 2013 ROHM Co., Ltd. All rights reserved. Rev.004 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 Datasheet BD8966FVM - Web Page Buy Distribution Inventory Part Number Package Unit Quantity Minimum Package Quantity Packing Type Constitution Materials List RoHS BD8966FVM MSOP8 3000 3000 Taping inquiry Yes