Data eet Datasheet Co ontroller typ pe switching g regulator with w high fre equency, hig gh accuracy y external FE ET Autom A matica ally Contr C rolled d BuckB -Boos st Sw witching Re egula ator BD9035AE B FV-C Ge eneral Descrip ption The BD9035 5AEFV-C is a buck-boost sw witching contrroller with a high withstand vo oltage and a wide input ra ange (VIN=3.8~30 0V) capable of o generating buck-boost ou utput with one in nductor. The IC has a ±7% high accu uracy switching fre equency for th he entire operrating tempera ature range (Ta=-4 40°C~+125°C C). Because off the automati cally controlled b buck-boost sysstem the BD9 9035AEFV-C also has a highe er efficiency compared c to regular switcching regulators e employing Sep pic or H-Bridge e systems. Key y Specificatio ons Input voltage e range: atures Fea Power su upply voltage: 40V (maximum m rating) Automaticcally controlled buck-boost system. ±7% High h accuracy sw witching freque ency (Ta=-40°C C~+125°C). PLL circuit for external synchronization: 600kHz 100kHz~6 Two-stage overcurrent protection through one exte ernal resistor Various p protection funcctions Undervolttage, overvoltage output de etection circuit & constant output monito or pin (PGOOD D) 00 Qualified AEC-Q10 ckage Pac HTSSOP-B2 24 3.8V to 30V V (Initial startup is over 4.5V V) 100kHz to 600kHz Oscillation frequency: Reference voltage v accuraacy: 0.8V±1.5% % Circuit curre ent at shutdow wn: 0μA (Typ..) Operating te emperature raange: -4 40℃ to +125℃ ℃ Ap pplications Automotivve micro contrroller, car audio and navigattion system, L LCD TV, PDP TV, DVD, PC, etc. W(Typ.) x D((Typ.) x H(Maxx.) 7.80mm x 7.60mm x 1.00m mm Figure 1. HT TSSOP-B24 pical Application Circuit Typ Figure e 2. Typical ap pplication circu uit diagram ○P Product structure e:Silicon mono olithic integrated d circuit .ww ww.rohm.com © 2014 2 ROHM Co o., Ltd. All rights reserved. TSZ Z22111・14・0 001 ○Thiis product is nott designed for protection againsst radioactive ra ays 1/23 TSZ002201-0T1T T0AL00110-1-2 19.Feb.2014 Rev.00 02 Datasheet BD9035AEFV-C Pin Configuration (TOP VIEW) GND CLKOUT SYNC TEST VDD RT OUTL SS PGND OVPLVL N.C. FB VL COMP N.C. PGOOD OUTH VREG3 N.C. VREG5 VCC EN CL VCCCL Figure 3. Pin configuration Pin Description Pin No. Symbol 1 GND 2 Function Pin No. Symbol Function Ground pin 13 VCCCL Overcurrent detection setting pin 1 TEST Test pin 14 EN 3 VDD NchFET drive supply pin 15 VREG5 5V internal power supply pin 4 OUTL NchFET drive pin 16 VREG3 3.5V internal power supply pin 5 PGND Power GND pin 17 PGOOD Power good output pin 6 N.C. Not connected 18 COMP 7 VL PchFET gate clamp pin 19 FB 8 N.C. Not connected 20 OVPLVL 9 OUTH PchFET drive pin 21 SS Soft start time setting pin 10 N.C. Not connected 22 RT Frequency setting pin 11 VCC Power supply pin 23 SYNC 12 CL Overcurrent detection setting pin 2 24 www.rohm.com © 2014 ROHM Co., Ltd. All rights reserved. TSZ22111・15・001 2/23 Output ON/OFF pin Error-amp output pin Feedback pin Overvoltage detection setting pin External input pin synchronization pulse CLKOUT Clock pulse output pin TSZ02201-0T1T0AL00110-1-2 19.Feb.2014 Rev.002 Datasheet BD9035AEFV-C Block Diagram 0.2V 0.1V 0.8V 1.6V 0.72V 0.88V 1.25V Figure 4. Block diagram www.rohm.com © 2014 ROHM Co., Ltd. All rights reserved. TSZ22111・15・001 3/23 TSZ02201-0T1T0AL00110-1-2 19.Feb.2014 Rev.002 Datasheet BD9035AEFV-C Description of Blocks ■Error amplifier (Error Amp) The error amplifier compares the output feedback voltage to the 0.8V reference voltage and provides the comparison result as COMP voltage, which is used to determine the switching duty. Because at startup, the soft start is triggered based on the soft start voltage, the COMP voltage is limited by the soft start voltage. ■Oscillator (OSC) The oscillation frequency is determined by the RT resistance and the current generated by the pin voltage. The oscillation frequency can be set in the range of 100 kHz to 600 kHz. ■SLOPE The slope block uses the clock produced by the oscillator to generate a sawtooth wave and sends this wave to the PWM comparator. ■PWM_BUCK The PWM_BUCK comparator determines the switching duty by comparing the output COMP voltage of the error amp, with the triangular wave of the SLOPE block. ■PWM_BOOST The PWM_BOOST comparator determines the switching duty by comparing the output voltage of the inverting amplifier, with the triangular wave of the SLOPE block. ■PGOOD pin 1) Output overvoltage detection (OVP) The PGOOD pin monitors the OVPLVL voltage and outputs “H” if the voltage is less than 0.88V (Typ.) and outputs “L” if the voltage exceeds 0.88V (Typ.). 2) Output undervoltage detection (SCP) The PGOOD pin monitors the output voltage (FB) and outputs “H” if the output voltage exceeds 90% (Typ.) and outputs “L” if the voltage is less than 90% (Typ.). Because the PGOOD pin is an open drain output, a pull up resistor should be connected when the pin is used. ■Overcurrent protection function (OCP_L, OCP_H) The overcurrent protection has a two-stage system with a control method as shown below. 1) OCP low level operations In case the inter VCCL-CL pin voltage exceeds 100mV (Typ.) the chip goes into OCP low level operations and the OUTH and OUTL pin pulses are limited. Also, in case this pulse limitation status continues for 256clk in a situation where the FB pin voltage drops below the undervoltage detection voltage VLOW, the soft start pin capacitor is discharged and the output is turned OFF for 8192clk. During the 8192clk in which the output is turned OFF the logic of OUTH and OUTL pin changes as follows; OUTH=H and OUTL=H. After the 8192clk the chip returns to normal operations and the soft start pin is recharged. 2) OCP high level operations In case the inter VCCL-CL pin voltage exceeds 200mV (Typ.), the chip goes into OCP high level operations, the soft start pin capacitor is discharged and the output is turned OFF for 8192clk. During the 8192clk in which the output is turned OFF the logic of OUTH and OUTL pin changes as follows; OUTH=H and OUTL=H. After the 8192clk the chip returns to normal operations and the soft start pin is recharged. Figure 5. Timing chart of two-stage overcurrent protection operations www.rohm.com © 2014 ROHM Co., Ltd. All rights reserved. TSZ22111・15・001 4/23 TSZ02201-0T1T0AL00110-1-2 19.Feb.2014 Rev.002 Datasheet BD9035AEFV-C ■Overvoltage protection function (OVPH) In case the OVPLVL pin voltage exceeds 1.25V (Typ.), the soft start pin capacitor is discharged and the output is turned OFF for 8192clk. During the 8192clk in which the output is turned OFF the logic of OUTH and OUTL pin changes as follows; OUTH=H and OUTL=H. After the 8192clk the chip returns to normal operations and the soft start pin is recharged. Figure 6. Overvoltage protection timing chart ■Soft Start The soft start block provides a function to prevent the overshoot of the output voltage Vo through gradually increasing the normal rotation input of the error amplifier when power supply turns ON to gradually increase the switching duty. The soft start time is set by the charge capacity of the soft start pin capacitor. (Refer to P. 17) ■Low voltage lockout circuit (UVLO) This is a Low Voltage Error Prevention Circuit. This prevents internal circuit error during increase of Power supply Voltage and during decline of Power supply Voltage. If the VCC drops below 3.4V (typ.), the UVLO is activated and the circuit is shut down. ■Thermal protection circuit (TSD) In order to prevent thermal destruction/thermal runaway of this IC, the TSD block will turn OFF the output when the chip temperature reaches approximately 150℃ or more. When the chip temperature falls to a specified level from thermal shutdown detection, the output will reset. However, since the TSD is designed to protect the IC, the margin for thermal design must be provided to guarantee that the chip junction temperature should be less than 150°C, which is the thermal shutdown detection temperature. www.rohm.com © 2014 ROHM Co., Ltd. All rights reserved. TSZ22111・15・001 5/23 TSZ02201-0T1T0AL00110-1-2 19.Feb.2014 Rev.002 Datasheet BD9035AEFV-C Absolute Maximum Ratings Parameter Symbol Limits Unit VCC 40 *1 V EN VCC V VCCCL VCC V VCL VCCCL V VCC-VL 13 V VDD VCC or 7 (whichever is lower) V VREG3 voltage VREG3 VCC or 7 (whichever is lower) V VREG5 voltage VREG5 VCC or 7 (whichever is lower) V SS voltage SS VREG3 V FB voltage FB VREG3 V OVPLVL VREG3 V COMP voltage COMP VREG3 V SYNC voltage SYNC VREG3 V PGOOD VREG3 V Pd 4.00 W Operating temperature range Topr -40~+125 ºC Storage temperature range Tstg -55~+150 ºC Tjmax 150 ºC VCC voltage EN voltage VCCCL voltage CL voltage Inter VCC-VL voltage VDD voltage OVPLVL voltage PGOOD voltage Power dissipation *2 Junction temperature *1 *2 Pd and ASO should not be exceeded. If mounted on a standard ROHM 4 layer PCB (copper foil area: 70x70mm) (Standard ROHM PCB size: 70x70x1.6mm) Reduce by 32mW for every 1℃ increase. (Above 25℃) Recommended Operating Rating(Ta=-40℃~125℃) Maximum ratings Parameter Symbol Unit Min. Max. Voltage power supply VCC 3.8 *3 30 V Oscillation frequency FOSC 100 600 kHz FSYNC 100 600 kHz External synchronization frequency *3 Initial startup is over 4.5V www.rohm.com © 2014 ROHM Co., Ltd. All rights reserved. TSZ22111・15・001 6/23 TSZ02201-0T1T0AL00110-1-2 19.Feb.2014 Rev.002 Datasheet BD9035AEFV-C Electrical Characteristic (unless otherwise specified: Ta=-40~125°C, VCC=12V, EN=5V) Limits Parameter Symbol Unit MIN. TYP. MAX. Condition 【Circuit Current】 Circuit current IVCC - 7 15 mA IST - 0 10 μA EN pin ON threshold voltage VENON 2.5 - - V EN pin OFF threshold voltage VENOFF - - 0.5 V REN 188 375 750 kΩ VVREG3 3.3 3.5 3.7 V VVREG5 4.5 5.0 5.4 V VUVLO 3.1 3.4 3.7 V VUVLOHYS 0.4 0.6 0.8 V FB input bias current IFB - 0 - μA FB=VFB2 Reference voltage 1 VFB1 0.792 0.800 0.808 V Ta=25 ºC Reference voltage 2 VFB2 0.788 0.800 0.812 V Ta=-40 ºC~+105 ºC ISS 5 10 15 μA SS=0.1V Oscillation frequency FOSC 326 350 375 kHz RT=33kΩ External synchronization frequency FSYNC - 350 - kHz SYNC=350kHz SYNC threshold voltage VSYNC 0.5 1.8 2.5 V SYNC pull down resistance RSYNC 125 250 500 kΩ SYNC input maximum ON duty DONMAX 80 - - % SYNC input minimum ON duty DONMIN - - 20 % Circuit current at shutdown EN=0V 【EN】 EN pull down resistance 【VREG3】 VREG3 output voltage 【VREG5】 VREG5 output voltage 【UVLO】 UVLO_VCC detection voltage UVLO hysteresis voltage 【Error amp】 【Soft start】 Soft start charge current 【Oscillator】 www.rohm.com © 2014 ROHM Co., Ltd. All rights reserved. TSZ22111・15・001 7/23 SYNC=3V TSZ02201-0T1T0AL00110-1-2 19.Feb.2014 Rev.002 Datasheet BD9035AEFV-C Parameter Symbol OUTH pin upper ON resistance Limits Unit Condition MIN. TYP. MAX. RONHH - 1.7 - Ω OUTH pin lower ON resistance RONHL - 3 - Ω OUTL pin upper ON resistance RONLH - 24 - Ω OUTL pin lower ON resistance RONLL - 22 - Ω Boost max duty 1 DBSTMAX1 - 92 - % f=600kHz Boost max duty 2 DBSTMAX2 60 - - % VCC=3.8V VCL1 86 100 114 mV Inter VCC-VL voltage VCL2 172 200 228 mV Inter VCC-VL voltage PGOOD pin ON resistance RPG - 0.1 0.4 kΩ PGOOD=0.15V,FB=0V PGOOD pin leak current IPG - 0 1 μA PGOOD=3.3V,FB=0.8V, Ta=-40~+105 ºC VOVER 0.85 0.88 0.91 V OVPLVL voltage VLOW 0.70 0.72 0.74 V FB voltage 【Driver】 【OCP】 Overcurrent detection CL pin voltage 1 Overcurrent detection CL pin voltage 2 【PGOOD】 Output overvoltage detection voltage Output undervoltage detection voltage www.rohm.com © 2014 ROHM Co., Ltd. All rights reserved. TSZ22111・15・001 8/23 TSZ02201-0T1T0AL00110-1-2 19.Feb.2014 Rev.002 Datasheet BD9035AEFV-C 95 10 90 9 85 8 80 75 f=350kHz Vo=6V 70 65 VCC=3.8V 60 CIRCUIT CURRENT AT SHUTDOWN : Istv [μA] EFFICIENCY [%] Typical Performance Curves (unless otherwise specified: Ta=25°C) VCC=6V 55 7 6 5 4 3 2 1 VCC=12V 50 0 0.0 0.5 1.0 1.5 2.0 -40 LOAD CURRENT [A] -20 0 20 40 60 80 100 120 AMBIENT TEMPERATURE : Ta[℃] Figure 7. Efficiency (Vo=6V, fosc=350 kHz) Figure 8. Circuit current at shutdown vs. temperature characteristics 9.0 1.0 7.0 0.9 REFERENCE VOLTAGE [V] CIRCUIT CURRENT [mA] 8.0 6.0 5.0 4.0 3.0 2.0 1.0 0.0 0.8 0.7 0.6 -40 -20 0 20 40 60 80 -40 100 0 20 40 60 80 100 AMBIENT TEMPERATURE : Ta[℃] AMBIENT TEMPERATURE : Ta[℃] Figure 9. Circuit current vs. temperature characteristics www.rohm.com © 2014 ROHM Co., Ltd. All rights reserved. TSZ22111・15・001 -20 Figure 10. Reference voltage vs. temperature characteristics 9/23 TSZ02201-0T1T0AL00110-1-2 19.Feb.2014 Rev.002 Datasheet BD9035AEFV-C Typical Performance Curves (unless otherwise specified: Ta=25°C) 350 OSILATING FREQUENCY : FOSC [kHz] INTER VCCL-CL PIN VOLTAGE [mV] 250 200 150 100 50 VCL1 VCL2 0 349 348 347 346 345 344 343 342 RT=33kΩ 341 340 -40 -20 0 20 40 60 80 100 -40 AMBIENT TEMPERATURE : Ta[℃ ] 0 20 40 60 80 100 AMBIENT TEMPERATURE : Ta[℃] Figure 11. Overcurrent detection CL pin voltage vs. temperature characteristics Figure 12. Oscillating frequency vs. temperature characteristics 11.0 4.3 10.8 4.2 UVLO THRESHOLD VOLTAGE [V] CHARGE CURRENT : Iss [μA] -20 10.6 10.4 10.2 10.0 9.8 9.6 9.4 4.1 4.0 3.9 3.8 3.7 Detection voltage(VUVLO) 3.6 Return voltage 3.5 9.2 9.0 3.4 -40 -20 0 20 40 60 80 100 -40 AMBIENT TEMPERATURE : Ta[℃] 0 20 40 60 80 100 120 AMBIENT TEMPERATURE : Ta[℃] Figure 13. Soft start charge current vs. temperature characteristics www.rohm.com © 2014 ROHM Co., Ltd. All rights reserved. TSZ22111・15・001 -20 Figure 14. UVLO detection/return voltage vs. temperature characteristics 10/23 TSZ02201-0T1T0AL00110-1-2 19.Feb.2014 Rev.002 Datasheet BD9035AEFV-C 1.2 2.05 FB PIN BIAS CURRENT : IFB [μA] EN THRESHOLD VOLTAGE : VEN [V] 2.10 2.00 1.95 1.90 1.85 1.80 1.75 1.70 1.0 0.8 0.6 0.4 0.2 FB=0V 0.0 -40 -20 0 20 40 60 80 100 -40 -20 AMBIENT TEMPERATURE : Ta[℃] 0.18 0.16 0.14 0.12 0.10 0.08 0.06 0.04 0.02 0.00 0 20 40 60 80 60 80 100 0.90 0.85 VOVER 0.80 VLOW 0.75 0.70 -40 100 -20 0 20 40 60 80 100 120 AMBIENT TEMPERATURE : Ta[℃] AMBIENT TEMPERATURE : Ta[℃] Figure 17. PGOOD pin ON resistance vs. temperature characteristics www.rohm.com © 2014 ROHM Co., Ltd. All rights reserved. TSZ22111・15・001 40 Figure 16. FB pin bias current vs. temperature characteristics OUTPUT OVER / LOW SENSE VOLTAGE [V] PGOOD ON RESISTANCE : PRG [kΩ] 0.20 -20 20 AMBIENT TEMPERATURE : Ta[℃] Figure 15. EN threshold voltage vs. temperature characteristics -40 0 Figure 18. Output overvoltage / undervoltage detection voltage vs. temperature characteristics 11/23 TSZ02201-0T1T0AL00110-1-2 19.Feb.2014 Rev.002 Datasheet BD9035AEFV-C Application Example N.B. There are many factors (PCB, output current, etc.) that can affect the DCDC characteristics. Please verify and confirm using practical applications. N.B. No connection (N.C) pin should not be connected to any other lines. N.B. Be sure to connect the TEST pin to ground. N.B. In case the external synchronization function is not used, be sure to connect SYNC pin to ground. N.B. This IC is not designed to operate as BOOST or BUCK application with single MOSFET. Be sure to use both M1 & M2. N.B. If EN pin is connected to VCC pin, please insert REN 150kΩ between the pins. REN EN VREG3 CVCCA CVCCB VCC BAT CVREG3 VCCCL power gnd VREG5 RCL CVREG5 power gnd CL power gnd CLKOUT CVL M1 OUTH DB SYNC Vo RT L1 VL RRT Vo COMP RCO CFB CCOA Vo power gnd power gnd VREG5 CCOB RFBB RFBC DA CVO VDD FB M2 OUTL RFBA PGND ROVB OVPLVL VREG3 ROVA SS TEST CVDD GND PGOOD power gnd RPGD CSS An example of parts values: In case of VCC=3.8~30V, Vo=5V, Io=0~3A, 350kHz Parts No. Value Parts No. Value DA RB225NS-40 L1 DB RB225NS-40 CVO 10μ (TDK SLF series) M1 RSJ250P10 RCO 2.2k M2 RSJ450N04 RFBA 15.6k 100μ(16V) RCL 13.33m RFBB 82k REN 150k RFBC 330 RRT 33k ROVA 15.6k RPGD 47k ROVB 82k CVDD 1μ (10V) CCOA 0.015μ (10V) 0.1μ (50V) CCOB 100p (10V) CVCCA 2.2μ (50V) CFB 680p (10V) CVCCB 220μ (50V) CVREG3 0.47μ (10V) CVREG5 0.47μ (10V) CSS 0.047μ (10V) CVL Directions for pattern layout of PCB 1) Design the wirings shown by heavy lines as short as possible. 2) Place the input ceramic capacitor CVCCA, CVCCB as close to the M1 as possible. 3) Place the RRT as close to the GND pin as possible. 4) Place the RFBA and RFBB as close to the FB pin as possible and provide the shortest wiring from the FB pin. 5) Place the ROVA and ROVB as close to the OVPLVL pin as possible and provide the shortest wiring from the OVPLVL pin. 6) Place the RFBA, RFBB, ROVA, and ROVB as far away from the L as possible. 7) Separate power GND and signal GND so that SW noise doesn’t affect the signal GND. www.rohm.com © 2014 ROHM Co., Ltd. All rights reserved. TSZ22111・15・001 12/23 TSZ02201-0T1T0AL00110-1-2 19.Feb.2014 Rev.002 Datasheet BD9035AEFV-C The control of automatic buck-boost system The following shows the switching state of three control modes. (1) Buck mode (VCC>>Vo) In case the input voltage is high compared to the output voltage, the chip will go into buck mode, resulting OUTH to repeatedly switch between H and L and that the OUTL will go to L (=OFF). This operation is the same as that of standard step-down switching regulators. Below, the OUTH and OUTL waveforms are shown. VCC × Dpon = Vo (eq.1) OUTH switching OUTL L IL Figure 19. (2) Buck-Boost mode (VCC≒Vo) In case the input voltage is close to the output voltage, the chip will go into buck-boost mode, resulting both the OUTH and OUTL to repeatedly switch between H and L. Concerning the OUTH, OUTL timing, the chip internally controls where the following sequence is upheld; when OUTH: H Æ L, OUTL: H Æ L. Shown below are the OUTH and OUTL waveforms. ① ② VCC > Vo VCC < Vo OUTH switching OUTH switching OUTL switching OUTL switching IL IL Figure 20. Figure 21. ※The timing excludes the SW delay The relationship between ON duty of PMOS (Dpon), ON duty of NMOS (Dnon), VCC and Vo is shown in the following equation. VCC × Dpon / (1-Dnon) = Vo (eq.2) The formula for calculation of Dpon and Dnon are shown in P.15. (3) Boost mode (VCC<<Vo) In case the input voltage is low compared to the output voltage, the chip will go into boost mode, resulting OUTH to go to L (=ON) and OUTL will repeatedly switch between H and L. This operation is the same as that of standard step-up switching regulators. Below, the OUTH and OUTL waveforms are shown Vo × (1-Dnon) = VCC (eq.3) Figure 22. www.rohm.com © 2014 ROHM Co., Ltd. All rights reserved. TSZ22111・15・001 13/23 TSZ02201-0T1T0AL00110-1-2 19.Feb.2014 Rev.002 Datasheet BD9035AEFV-C (4) Mode transfer voltage and duty control Vo, the gain of the inverting amplifier and the cross duty determines the transfer voltage at buck to buck-boost mode and buck-boost to boost mode. The general description is shown below. The duty of OUTH is controlled by output of error amp (COMP) and SLOPE voltage. Also, OUTL duty is controlled by the output voltage of the inverting amplifier in chip (BOOSTCOMP) and SLOPE voltage. In case VCC = Vo, because COMP voltage becomes equal to BOOSTCOMP voltage, OUTH and OUTL switch simultaneously. VCC=Vo (Typ.) COMP 100% Cross duty 85%(Typ.) SLOPE 0% BOOSTCOMP Buck Buck-Boost Boost Figure 23. Buck-Boost operation controlled by COMP, BOOSTCOMP and SLOPE voltage ON duty of PMOS in this condition is called the cross duty (Dx = 0.85, Typ.). Dpon and Dnon can be calculated by the following equation, assuming the gain of the inverting amplifier as A (1.5, Typ.). Dnon = 1 – Dx + A (Dpon – Dx) Dnon = 1.5Dpon – 1.125 (※) (eq.4) From eq.3, eq.4 and Dpon=1, the input voltage at transition between buck-boost and boost mode is calculated by following; VCC = {Dx – A (1 – Dx)} Vo VCC = 0.625×Vo (※) Also, from eq.1, eq.4 and Dnon=1, the input voltage at transition between buck-boost and buck mode is calculated by following; VCC = Vo×A / {(1 + A)Dx – 1} VCC = 1.333×Vo (※) ※in case of A=1.5(Typ.) and Dx=0.85(Typ.) 88 87 ク ロス duty [%] 86 Cross duty [%] Be sure to confirm Dx and A values under the actual application because these parameters vary depending on conditions of use and parts. Dx varies with oscillating frequency shown in Fig.24. In addition, ‘A’ value can be calculated by Δdnon/Δdpon. 85 84 83 PMOS: RSD080P05 NMOS: RSD150N06 82 81 0 100 200 300 400 500 600 700 800 発振周波数 Frequency[kHz] [kHz] Figure 24. Cross duty vs. frequency characteristics www.rohm.com © 2014 ROHM Co., Ltd. All rights reserved. TSZ22111・15・001 14/23 TSZ02201-0T1T0AL00110-1-2 19.Feb.2014 Rev.002 Datasheet BD9035AEFV-C Selection of Components Externally Connected (1)Setting the output L value The coil value significantly influences the output ripple current. Thus, as seen in bellow, the larger the coil, and the higher the switching frequency, the lower the drop in ripple current. The optimal output ripple current setting is 30% of maximum current. Buck mode Buck-Boost mode VCC > Vo Boost mode VCC < Vo _ ΔIL:ripple current, I L:average coil current, f:oscillating frequency Dpon:PMOS ON duty = Vo×Dx (1+A) / (VCC+A×Vo) =2.13×Vo / (Vcc+1.5×Vo) (Typ.) Dnoff:NMOS ON duty = (1+A)×Dx – A×Dpon =2.13 – 1.5×Dpon (Typ.) An output current in excess of the coil current rating will cause magnetic saturation to the coil and decrease efficiency. The following equation shows the peak current ILMAX assuming the efficiency as η. It is recommended to provide a sufficient margin to ensure that the peak current does not exceed the coil current rating. Ι LMAX = ΔΙ ⎞ 1⎛ ⎜ ΙL + L ⎟ η⎝ 2 ⎠ Use low resistance (DCR, ACR) coils to minimize coil loss and increase efficiency. (2)Setting the output Co value Select output capacitor with consideration to the ripple voltage (ΔVp-p) tolerance. The following equation is used to determine the output ripple voltage. Buck mode Boost mode The output Co setting needs to be kept within the allowable ripple voltage range. Allow for a sufficient voltage output margin in establishing the capacitor rating. Low ESR capacitors provide a lower output ripple voltage. Because the output startup time needs to be set within the soft start time, please take the conditions described in the flowing equation also in consideration when selecting the value of the output capacitor. TSS × (Ilimit – Io) TSS:Soft start time Co ≦ Vo Ilimit:Over current detection value N.B. Non-optimal capacitance values may cause startup problems. Especially in cases of extremely large capacitance values, the possibility exists that the inrush current at startup will activate the overcurrent protection, thus not starting the output. Therefore, verification and conformation with the actual application is recommended. www.rohm.com © 2014 ROHM Co., Ltd. All rights reserved. TSZ22111・15・001 15/23 TSZ02201-0T1T0AL00110-1-2 19.Feb.2014 Rev.002 Datasheet BD9035AEFV-C (3)Setting the input capacitor (Cin) The input capacitor serves to lower the output impedance of the power source connected to the input pin (VCC, VCCCL). Increased power supply output impedance can cause input voltage (VCC) instability and may negatively impact oscillation and ripple rejection characteristics. Therefore, it is necessary to place the input capacitor in close proximity to the MOSFET and PGND pin. Select a low-ESR capacitor with little change in capacitance due to temperature change and with a sufficiently large ripple current. The ripple current IRMS is determined by the following equation: VCC Cin L Vo Co Vo(VCC - Vo) VCC IRMS = Io × [A] Figure 25. Also, be certain to ascertain the operating temperature, load range and MOSFET conditions for the application in which the capacitor will be used, since capacitor performance is heavily dependent on the application’s input power characteristics, substrate wiring and MOSFET gate drain capacity. (4)Setting the output voltage The output voltage is determined by the equation below. Select a combination of R1 and R2 to obtain the required voltage. Note that a small resistance value leads to a drop in power efficiency and that a large resistance value leads, due to the error amp output drain current to an increase of the offset voltage. Vo Vo = 0.8× 0.8V RFBA + RFBB RFBB RFBA FB RFBA Figure 26. (5)Setting the oscillation frequency The internal oscillation frequency setting is possible with the corresponding value of resistor connected to RT pin. The setting range is 100kHz to 600kHz. The correlation between the resistance value and the oscillation frequency is shown in the table below. Settings outside of this range can lead to a switching stop and consequentially operations cannot be guaranteed. 700 600 RT resistance 18.7kΩ 20kΩ 22.5 kΩ 24kΩ 27kΩ 28.5kΩ 30kΩ 33kΩ 47kΩ 62kΩ 91kΩ 120kΩ FREQUENCY:f[kHz] 500 400 300 200 100 Oscillation frequency 600kHz 550kHz 500kHz 470kHz 424kHz 400kHz 384kHz 350kHz 250kHz 192kHz 133kHz 100kHz 0 0 20 40 60 80 100 120 140 RT RESITANCE :RRT[kΩ] Figure 27. RT resistance vs. oscillation frequency www.rohm.com © 2014 ROHM Co., Ltd. All rights reserved. TSZ22111・15・001 16/23 TSZ02201-0T1T0AL00110-1-2 19.Feb.2014 Rev.002 Datashe Datasheet eet BD D9035AEF FV-C (6)Setting the so oft start time The soft start function is necessary n to prevent p inrush of coil currentt and output vo oltage overshooot at startup. The figure be elow elation betwee en soft start de elay time and capacitance, which can be calculated byy using the equ uation to the right shows the re of the figure e. Figure 29. Soft start tim me TSS TSS = 8 [V] (Typ.) × C CSS [μF] 0.8 [sec] S [μA] (Typ.:110μA) ISS F Figure 28. Sofft Start capacitance vs. dela ay time Capacitance e values betw ween 0.01μF and a 0.1μF are recommende ed. There is a possibility thaat an overshoo ot is generated in the output d due to the ph hase constantt, output capa acitance, etc. Therefore, verification andd confirmation n with the acctual application iis recommend ded. Use high h accuracy co omponents (e.g. x5R) when n implementingg sequential startups s involvving other powerr sources. (7)MOSFET sele ection • PchMOS used for step-down s FET T ating > VCC o VDSS maximum ra o VGSS maximum ra ating > Lower value of 13V o or VCC N.B. T The voltage be etween VCC-V VL is kept at 10 0.3V(Typ.), 13 3V(Max.). o Allo owable curren nt > Coil peak current ILMAX N.B. A value above the overcurre ent protection ssetting is recom mmended. N.B S Selecting a low w ON resistanc ce is conducivve to achieving g a high h efficiency. • NchM MOS used for step-up s FET o VDSS maximum ra ating > VO o VGSS maximum ra ating > VDD o Allo owable curren nt > Coil peak current ILMAX N.B. A value above the overcurre ent protection ssetting is recom mmended. N.B S Selecting a low w ON resistanc ce is conducivve to achieving g a high h efficiency. (8)Schottky barriier diode selecction • Reverrse voltage VR > VCC • Allowa able current > Coil peak currrent ILMAX N.B. A value above the overcurre ent protection ssetting is recom mmended. N.B. S Selecting a dio ode with a low w forward volta age and fast recove ery is conduciive to achievin ng a high efficiiency. Figure 30 0 VC CC Vo VR Figure 31 ww ww.rohm.com © 2014 2 ROHM Co o., Ltd. All rights reserved. TSZ Z22111・15・0 001 17/23 TSZ002201-0T1T T0AL00110-1-2 19.Feb.2014 Rev.00 02 Datasheet BD9035AEFV-C (9) Setting the phase compensation The phase compensation is set by the capacitors and resistors connected in parallel to COMP and FB pin, and RFBB. At first, it is easier to achieve stability at any power supply and load condition by adjusting values at the lowest voltage power supply and maximum load. Non-optimum values can cause unstable output, like oscillation. Assuming RFBB>>RFBC and CCOA>>CCOB, each phase compensation elements make phase delay fp1and fp2, phase lead fz1 and fz2, which can be determined by the formulas below. fp1 = 1 2π×CFB×RFBC fp2 = 1 2π×CCOB×RCO fz1 = 1 2π×CFB×RFBB fz2 = 1 2π×CCOA×RCO This setting is obtained by using a simplified calculation; therefore, adjustment on the actual application may be required. Also as these characteristics are influenced by the substrate layout, load conditions, etc., verification and confirmation with the actual application at time of mass production design is recommended. (10)Switching pulse jitter and split Depending on the type of external FET and diode there may be jitter and split in the switching pulse. In case this jitter and split becomes a problem please use the following countermeasures. • Add a resistor to the OUTH gate of the step-down FET. • Add a resistor to the OUTL gate of the step-up FET. However, as these characteristics are influenced by the substrate pattern, used FET, etc., verification and confirmation with the actual application is recommended. VCC VcccL CL OUTH Vo OUTL Figure 32. (11)Measurement of the open loop of the DC/DC converter To measure the open loop of the DC/DC converter, use the gain phase analyzer or FRA to measure the frequency characteristics. VO DC/DC converter controller ++ ① ② ① <Procedure> 1. Check to ensure output causes no oscillation at the maximum load in closed loop. 2. Isolate ① and ② and insert Vm (with amplitude of approximately. 100mVpp). 3. Measure (probe) the oscillation of ① to that of ②. RL ② Vm Figure 33. Thermal derating characteristics 70mm×70mm×1.6mm, occupied copper foil is less than 3%, glass epoxy substrate, the board and the back exposure heat radiation board part of package are connected with solder. HTSSOP-B24 POWER DISSIPATION: Pd [W] 4.5 ④4.00W 4.0 3.5 ①1 layer board (copper foil 0mm × 0mm) θja=113.6℃/W ②2 layer board (copper foil 15mm × 15mm) θja=73.5℃/W ③2 layer board (copper foil 70mm × 70mm) θja=44.6℃/W ④4 layer board (copper foil 70mm × 70mm) θja=31.3℃/W ③2.80W 3.0 2.5 2.0 ②1.70W 1.5 ①1.10W 1.0 0.5 0.0 0 25 50 75 100 125 150 A MBIENT TEMPERA TURE : Ta[℃ ] 175 CAUTION: Pd depends on number of the PCB layer and area. This value is measurement value, but not guaranteed value. Figure 34. Thermal derating characteristics www.rohm.com © 2014 ROHM Co., Ltd. All rights reserved. TSZ22111・15・001 18/23 TSZ02201-0T1T0AL00110-1-2 19.Feb.2014 Rev.002 Datasheet BD9035AEFV-C I/O equivalence circuits VDD VCC OUTL EN PGND GND GND VREG3 VREG3 COMP FB 10k 1.5p VCC VREG3 VCCCL RT CL www.rohm.com © 2014 ROHM Co., Ltd. All rights reserved. TSZ22111・15・001 19/23 TSZ02201-0T1T0AL00110-1-2 19.Feb.2014 Rev.002 Datasheet BD9035AEFV-C Operational Notes 1) Absolute maximum ratings Exceeding the absolute maximum rating for supply voltage, operating temperature or other parameters can result in damages to or destruction of the chip. In this event it also becomes impossible to determine the cause of the damage (e.g. short circuit, open circuit, etc.). Therefore, if any special mode is being considered with values expected to exceed the absolute maximum ratings, implementing physical safety measures, such as adding fuses, should be considered. 2) GND electric potential Keep the GND terminal potential at the lowest (minimum) potential under any operating condition. 3) Thermal design Use a thermal design that allows for a sufficient margin with regard to the power dissipation of the actual operating situation. 4) Inter-pin shorting and mounting errors Ensure that when mounting the IC on the PCB the direction and position are correct. Incorrect mounting may result in damaging the IC. Also, shorts caused by dust entering between the output, input and GND pin may result in damaging the IC. 5) Operation in strong electromagnetic fields Use caution when operating in the presence of strong electromagnetic fields, as this may cause the IC to malfunction. 6) Common impedance With regard to the wiring of the power supply and of the ground, take sufficient care to decrease the common impedance and to make the ripple as small as possible (by making the wiring as wide and short as possible, reducing ripple by L, C, etc.). 7) Thermal shutdown (TSD) Temperature Protect Circuit (TSD Circuit) is built-in in this IC. As for the Temperature Protect Circuit (TSD Circuit), because it a circuit that aims to block the IC from insistent careless runs, it is not aimed for protection and guarantee of IC. Therefore, please do not assume the continuing use after operation of this circuit and the Temperature Protect Circuit operation. 8) Rush current at power ON With CMOS Ics and Ics featuring multiple power supplies the possibility exists of an instantaneous current rush when the power is turned ON. Therefore, attention should be given to the power coupling capacitance and power and ground wiring width and route. 9) Power input at shutdown If VCC starts up rapidly at shutdown (EN=OFF), VREG3 voltage may be output and this may cause the IC to malfunction. Therefore, set the rise time of VCC to under 40V/ms. 10) About IC Pin Input 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, creating a parasitic diode or transistor. Relations between each potential may form as shown in the example below, where a resistor and transistor are connected to a pin: z With the resistor, when GND> Pin A, and with the transistor (NPN), when GND>Pin B: The P-N junction operates as a parasitic diode. z With the transistor (NPN), when GND> Pin B: The P-N junction operates as a parasitic transistor by interacting with the N layers of elements in proximity to the parasitic diode described above. Parasitic diodes inevitably occur in the structure of the IC. Their operation can result in mutual interference between circuits and can cause malfunctions and, in turn, physical damage to or destruction of the chip. Therefore do not employ any method in which parasitic diodes can operate such as applying a voltage to an input pin that is lower than the (P substrate) GND Resistor Transistor (NPN) (Pin A) (Pin B) B C E (Pin B) (Pin A) P N P P + P + N P N Parasitic element P + P N B + N P-Substrate GND C Parasitic element E GND Parasitic element GND Parasitic element Figure 35. www.rohm.com © 2014 ROHM Co., Ltd. All rights reserved. TSZ22111・15・001 20/23 TSZ02201-0T1T0AL00110-1-2 19.Feb.2014 Rev.002 Datasheet BD9035AEFV-C 11) About TEST pin Note that the TEST pin will go into test mode that masks protection functions when supplied with voltage. Be sure to connect TEST pin to ground. 12) About VREG3, VREG5 pin VREG3 and VREG5 output pins are designed to supply power only into this IC. Thus, it is not recommended to use them for other purposes. Ordering Information B D 9 0 3 5 A Parts Number E F V Package EFV: HTSSOP-B24 - C E2 Product Rank C: for Automotive Packaging specification E2: Embossed tape and reel Marking Diagram HTSSOP-B24 (TOP VIEW) Part Number Marking BD9035A LOT Number 1PIN MARK www.rohm.com © 2014 ROHM Co., Ltd. All rights reserved. TSZ22111・15・001 21/23 TSZ02201-0T1T0AL00110-1-2 19.Feb.2014 Rev.002 Datashe Datasheet eet BD D9035AEF FV-C Physical Dimen nsion, Tape an nd Reel Inforrmation Package P Na ame HT TSSOP-B24 4 <Ta Tape and Reell information> in T Tape Emb bossed carrier tape pe (with dry pack)) Q Quantity 2000 00pcs Direction D of o feed E2 The he direction is the 1pin 1p of product is att the t upper left when en you hold ( ree a you pull out the hand eel on the left hand and he tape on the rightt h Direction n of o feed 1pin Ree eel ww ww.rohm.com © 2014 2 ROHM Co o., Ltd. All rights reserved. TSZ Z22111・15・0 001 ) rder quantity needs to be b multiple of the minimum min quantity. ∗ Orde 22/23 TSZ002201-0T1T T0AL00110-1-2 19.Feb.2014 Rev.00 02 Datasheet BD9035AEFV-C Revision History Date Revision Change log 2013.7.30 001 New version created. 2014.2.19 002 Added the term about AEC-Q100. (P.1) Replaced “Physical Dimension, Tape and Reel Information” with new format. (P.22) www.rohm.com © 2014 ROHM Co., Ltd. All rights reserved. TSZ22111・15・001 23/23 TSZ02201-0T1T0AL00110-1-2 19.Feb.2014 Rev.002 Datasheet Notice Precaution on using ROHM Products 1. If you intend to use our Products in devices requiring extremely high reliability (such as medical equipment (Note 1), aircraft/spacecraft, nuclear power controllers, 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 not designed 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-PAA-E © 2015 ROHM Co., Ltd. All rights reserved. Rev.001 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. 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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 concerned goods might be fallen under listed items of export control prescribed by Foreign exchange and Foreign trade act, please consult with ROHM in case of export. Precaution Regarding Intellectual Property Rights 1. 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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-PAA-E © 2015 ROHM Co., Ltd. All rights reserved. Rev.001 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