TECHNICAL NOTE High-performance Regulator IC Series for PCs Switching Regulators for DDR-SDRAM Cores BD9535MUV Description BD9535MUV is a 2ch switching regulator controller with high output current which can achieve low output voltage (0.7V～ 2.0V) from a wide input voltage range (4.5V～25V). High efficiency for the switching regulator can be realized by utilizing an 3 TM external N-MOSFET power transistor. A new technology called H Reg is a Rohm proprietary control method to realize TM ultra high transient response against load change. SLLM (Simple Light Load Mode) technology is also integrated to improve efficiency in light load mode, providing high efficiency over a wide load range. For the soft start/stop function, variable frequency function, short circuit protection function with timer latch, and tracking function are all built in. This 2ch switching regulator is specially designed for Chipset and Front Side Bus. Features 3 TM 1) 2ch H REG Switching Regulator Controller 2) Light Load Mode and Continuous Mode Changeable 3) Thermal Shut Down (TSD), Under Voltage LockOut (UVLO), Over Current (detect the peak current) Protection (OCP), Over Voltage Protection (OVP), Short circuit protection with built-in timer-latch 4) Soft start function to minimize rush current during startup 5) Switching Frequency Variable (f=200KHz～600kHz) 6) VQFN032V5050 package 7) Built-in Power good circuit 8) Adjustable to chip set spec by tracking function Applications Laptop PC, Desktop PC, LCD-TV, Digital Components Sep. 2008 ●Maximum Absolute Ratings (Ta=25℃) Parameter Symbol Rating V V Input Voltage 1 VCC 7 Input Voltage 2 VDD 7 *1 Input Voltage 3 BOOT Voltage BOOT-SW Voltage HG-SW Voltage VIN VBOOT1/2 VBOOT1-VSW1, VBOOT2-VSW2 VHG1-VSW1, VHG2-VSW2 Unit *1 30 *1 V 35 *1 V 7 *1 V *1 V 7 LG Voltage VLG1/2 VDD V Setting for Output Voltage VREF1/2 VCC V Output voltage VIs+1/2, VIs-1/2 VCC V SS Voltage VSS1/2 VCC V FS Voltage VFS VCC V VREG VCC V VILIM1/2 VCC V *1 V 7 *1 V *1 V VREG voltage Current Limit setting Voltage Logic Input Voltage PGOOD Voltage CE Voltage Power dissipation Operating Temperature Range Storage Temperature Range VEN1/2 7 VPGOOD1/2 VCE1/2 7 Pd T.B.D W Topr -10～+100 ℃ Tstg -55～+150 ℃ Tjmax +150 ℃ Symbol Min. Max. Unit Input Voltage 1 VCC 4.5 5.5 V Input Voltage 2 VDD 4.5 5.5 V Input Voltage 3 VIN 3.0 28 V BOOT Voltage VBOOT1/2 4.5 30 V VSW1/2 -2 33 V BOOT-SW Voltage VHG1-VSW1, VHG2-VSW2 4.5 5.5 V Logic Input Voltage VEN1/2 0 5.5 V Setting Voltage for Output Voltage VREF1/2 0.7 2.0 V VIs+1/2, VIs-1/2 0.7 2.0 V tonmin - 100 nsec Junction Temperature *1 Not to exceed Pd. ●Operating Conditions (Ta=25℃) Parameter SW Voltage Is Input Voltage MIN ON time ★ This product should not be used in a radioactive environment. 2/18 ●ELECTRICAL CHARACTERISTICS (unless otherwise noted, Ta=25℃ VCC=5V,VDD=5V,VEN=3V,VIN=12V,VREF=1.8V,RFS=68kΩ) Standard Value Parameter Symbol MIN. TYP. MAX. [Whole Device] VCC bias current VIN bias current VCC standby current VIN standby current EN Low voltage 1,2 EN High voltage 1,2 (forced continuous mode) EN High voltage 1,2 (SLLM mode) EN bias current 1,2 VREG voltage [Under voltage lock out block] VCC threshold voltage VCC hysteresis voltage VIN threshold voltage VIN hysteresis voltage VREG threshold voltage VREG hysteresis voltage [Over Voltage Protection block] VOUT threshold voltage 1,2 [Power Good block] VOUT Power Good Low voltage 1,2 VOUT Power Good High voltage 1,2 Discharge ON resistance 1,2 Delay time 1,2 [H3REGTM Control block] ON Time1 MAX ON Time 1 MIN OFF Time 1 ON Time 2 MAX ON Time 2 MIN OFF Time 2 [FET Driver block] HG upper side ON resistance 1,2 HG lower side ON resistance 1,2 LG upper side ON resistance 1,2 LG lower side ON resistance 1,2 [Soft Start block] Charge current Discharge current Discharge threshold voltage Standby voltage [Current Limit block] Current limit threshold voltage 1_1,2 Current limit threshold voltage 2_1,2 Reflux current limit threshold voltage1_1,2 Reflux current limit threshold voltage2_1,2 [Output Voltage Sense block] VIs offset voltage1,2 REF bias current1,2 Is+ input current1,2 Is- input current1,2 [SCP block] Threshold voltage 1,2 Delay time 1,2 Unit Icc IIN Istb IIN_Stb VEN_low1,2 GND 1.4 200 20 - 2.0 400 20 40 0.8 mA μA μA μA V VENth_con1,2 2.3 - 3.8 V VENth_sllm1,2 IEN1,2 4.2 - 7 5.5 10 V μA VREG1,2 2.475 2.500 2.525 V Vcc_UVLO dVcc_UVLO VIN_UVLO dVIN_UVLO VREG_UVLO dVREG_UVLO 4.1 100 2.4 100 2.0 100 4.3 160 2.6 160 2.2 160 4.5 220 2.8 220 2.4 220 V mV V mV V mV VOUT_OVP1,2 VREF×1.15 VREF×1.20 VREF×1.25 Conditions VEN1=VEN2=0V VEN1=VEN2=0V IREG=500μA Ta=-10～100℃*2 VCC:Sweep up VCC:Sweep down VIN:Sweep up VIN:Sweep down VREG:Sweep up VREG:Sweep down V VPGOOD_low1,2 VREF×0.87 VREF×0.90 VREF×0.93 V VREF× VREF× VREF× VPGOOD_high1,2 V 1.07 1.10 1.13 Ron_PGOOD1,2 1.0 2.0 kΩ TPGOOD1,2 150 250 350 μsec ton1 Tonmax1 Toffmin1 500 3.0 600 350 3.0 600 600 3.5 700 450 3.5 700 nsec μsec nsec RFS=68kΩ nsec RFS=68kΩ Tonmax2 Toffmin2 400 2.5 500 250 2.5 500 RHGhon1,2 RHGlon1,2 RLGhon1,2 RLGlon1,2 - 3.0 2.0 2.0 0.5 6.0 4.0 4.0 1.0 Ω Ω Ω Ω ISS_char1,2 ISS_dis1,2 VSS_disth1,2 VSS_STB1,2 1.5 1.5 - 2 2 0.1 - 2.5 2.5 0.2 50 μA μA V mV VIlim11,2 VIlim21,2 VReIlim11,2 VReIlim21,2 40 170 -60 -230 50 200 -50 -200 60 230 -40 -170 mV mV mV mV VILIM=0.5V VILIM =2.0V VILIM =0.5V VILIM =2.0V VIS_off1,2 IREF1,2 IIs+1,2 IIs-1,2 VREF -3m -100 -100 -100 VREF 0 0 0 VREF +3m 100 100 100 V nA nA nA Ta=-10～100℃*2 Vthscp1,2 tscp1,2 0.7 VREF×0.7 1 1.3 V msec ton2 *2 Designed guarantee 3/18 μsec nsec VIs+=1.8V VIs-=1.8V ●Block Diagram VCC EN1 VIN VREF VIN Reference Block VREG SS1 UVLO SS 2.5V BOOT1 2.5VReg SLLM1 REF×0.7 SS×0.7 Is-1 EN1 EN2 Delay 3 H Reg Controller Block FS SS IS-1 Soft Start /Stop Block HG1 SW1 SCP REF1 Thermal Protection BEN + + - TSD Q R S Driver Circuit SLLM VDD LG1 SLLM1 Current Limit PGND1 OVP1 + - ILIM UVLO ILIM SCP TSD CE1 Is-1 Is+1 ILIM1 PGOOD1 VCC Is-1 Is-2 VREF VIN Reference Block EN2 UVLO SLLM2 SS2 BOOT2 HG2 SCP Delay 3 H Reg Controller Block REF2 + + - Q R S SLLM SW2 Driver Circuit VDD SLLM2 Current Limit ILIM UVLO ILIM SCP TSD GND PGOOD2 OVP2 Soft Start /Stop Block BEN SS IS-2 OVP1 GOOD SS VIN REF×0.7 SS×0.7 Is-2 POWER LG2 + - PGND2 OVP2 CE2 ILIM2 FS ●Pin Function Table PGOOD2 EN2 SS2 ILIM2 REF2 EN1 CE2 PIN name BOOT1 CE1 PGOOD1 BOOT2 PIN No. 1 2 3 HG2 ●Pin Configuration IS+2 IS-2 4 24 23 22 21 20 19 18 17 5 SW2 25 16 VIN PGND2 26 15 Is-2 LG2 27 14 Is+2 VDD 28 13 VCC LG1 29 12 GND 1 2 3 4 5 6 7 8 19 SS2 ILIM1 REF1 VREG 9 FS SS1 HG1 32 EN1 10 Is-1 PGOOD1 SW1 31 CE1 11 Is+1 ILIM1 REF1 VREG FS Is-1 Is+1 GND VCC Is+2 Is-2 VIN REF2 ILIM2 BOOT1 PGND1 30 SS1 6 7 8 9 10 11 12 13 14 15 16 17 18 20 EN2 21 22 23 24 25 26 27 28 29 30 31 32 reverse PGOOD2 CE2 BOOT2 HG2 SW2 PGND2 LG2 VDD LG1 PGND1 SW1 HG1 FIN 4/18 PIN function HG driver power supply pin 1 Reactive pin 1 for lower ESR output capacitor Power good signal output pin 1 Enable input pin 1 (0～0.8V:OFF, TM 2.3～3.8V:continuous mode, 4.2～5.5V:SLLM ) Connective pin 1 of capacitor for soft start/soft stop Current limitsetting pin 1 Output voltage setting pin 1 Reference voltage inside IC (Output : 2.5V) Resistance connective pin for setting frequency Current sense pin- 1 Current sense pin+ 1 Sense GND Power supply input pin Current sense pin+ 2 Current sense pin- 2 Battery voltage sense pin Output voltage setting pin 2 Current limit setting pin 2 Connective pin 2 of capacitor for soft start/soft stop Enable input pin 2 (0～0.8V:OFF, TM 2.3～3.8V:continuous mode, 4.2～5.5V:SLLM ) Power good signal input pin 2 Reactive pin 2 for lower ESR output capacitor HG driver power supply pin 2 High side FET gate drive pin 2 High side FET source pin 2 Power GND2 Low side FET gate drive pin 2 Power supply input pin Low side FET gate drive pin 1 Power GND 1 High side FET source pin 1 High side FET gate drive pin 1 substrate ●Reference Data 100 100 90 VO 80 Efficiency[%] Efficiency[%] 80 60 40 VIN=7V VIN =12V VIN =19V 20 100[mV/div] 70 60 40 VIN=7V VIN =12V VIN =19V 30 20 0 HG LG 50 IO 5[A/div] 10 0.01 0.1 1 Load Current[A] 10 0.01 Fig.1 Io-efficiency （SLLM） 0.1 1 Load Current[A] 10 Fig.2 Io- efficiency （Continuous mode） VO VO VO 100[mV/div] Fig.3 Transitional response (Io=0→5A) （Continuous mode） 100[mV/div] 100[mV/div] HG LG HG LG HG LG IO 5[A/div] IO 5[A/div] IO 5[A/div] Fig.4 Transitional response (Io=5→0A) （Continuous mode） Fig.5 Transitional response (Io=0→5A) （SLLM） Fig.6 VO VO VO HG SW LG HG SW LG HG SW LG Fig.7 SLLM：Io=0A Transitional response (Io=5→0A) （SLLM） Fig.9 SLLM：Io=1A Fig.8 SLLM：Io=0.4A 500 EN Frequency [kHz] 400 EN 300 200 100 Continuous mode VIN=7V VIN =12V VIN =19V PGOOD SLLM VIN=7V VIN =12V VIN =19V 0.1 1 Load Current[A] Fig.10 Io-Frequency SS VO SS VO 0 0.01 PGOOD 10 Fig.11 starting wave 5/18 Fig.12 stopping wave ●Evaluation Board Circuit VDD VCC 5V VREG VIN R4 12V 0.5V R5 VDD VDD BOOT1 C2 HG1 VREG VREG R3 C3 VCC R7 5V R8 R6 U1 VCC BD9535MUV VQFN032V5050 C1 VDD R2 SW1 C6 VREG R1 EN1 VIN R31 HG1 C14 SW1 R32 LG1 C4 Is+1 R12 R18 C8 BOOT2 HG2 EN1 C9 HG2 R45 SW2 C24 M2 SS2 C12 PGOOD1 C26 C25 1.2V/5A R50 C28 C29 R51 R61 C31 Is-2 FS GND C30 D4 R62 PGOOD2 TRACK2 R26 R41 L2 M2 R46 Is+2 REF2 C11 R44 PGND2 R23 R24 VCC LG2 LG2 C10 1.2V R39 SW2 ILIM2 R21 C20 C23 VIN D2 R20 VREG C19 VDD R17 0.5V R38 R60 R16 VREG SW2 5V R19 C18 D3 PGOOD1 SS1 EN2 C7 1.8V/5A R37 L1 C21 Is-1 VCC C16 R59 REF1 TRACK1 C15 M1 M1 R33 R14 R11 VIN PGND1 C5 R10 GND PGND1 PGND2 LG1 VREG(2.5V) ILIM1 1.8V C13 PGND SW1 EN1 R9 D1 GND R52 VCC R54 PGOOD2 FS R57 R25 R58 ●Evaluation Board Parts List Designation R1 R2 R3 R4 R5 R6 R7 R8 R9 R10 R11 R12 R14 R16 R17 R18 R19 R20 R21 R23 R24 R25 R26 R31 R32 R33 R37 R38 R39 R41 R44 R45 R46 R50 R51 R52 Value 10Ω 0Ω 1kΩ 200kΩ 51kΩ 0Ω 51kΩ 91kΩ 0Ω 22kΩ 56kΩ 0Ω 10kΩ 51kΩ 91kΩ 0Ω 200kΩ 51kΩ 0Ω 39kΩ 36kΩ 0Ω 10kΩ 0Ω 0Ω 0Ω 7mΩ 0Ω 0Ω 100kΩ 0Ω 0Ω 0Ω 7mΩ 0Ω 0Ω Part No. MCR03EZPF10R0 MCR03EZHJ000 MCR03EZPF1001 MCR03EZPF2003 MCR03EZPF5102 MCR03EZHJ000 MCR03EZPF5102 MCR03EZPF9102 MCR03EZHJ000 MCR03EZPF2202 MCR03EZPF5602 MCR03EZHJ000 MCR03EZPF1002 MCR03EZPF5102 MCR03EZPF9102 MCR03EZHJ000 MCR03EZPF2003 MCR03EZPF5102 MCR03EZHJ000 MCR03EZPF3902 MCR03EZPF3602 MCR03EZHJ000 MCR03EZPF1002 MCR03EZHJ000 MCR03EZHJ000 MCR03EZHJ000 PMR100HZPFU7L00 MCR03EZHJ000 MCR03EZHJ000 MCR03EZPF1003 MCR03EZHJ000 MCR03EZHJ000 MCR03EZHJ000 PMR100HZPFU7L00 MCR03EZHJ000 MCR03EZHJ000 Company ROHM ROHM ROHM ROHM ROHM ROHM ROHM ROHM ROHM ROHM ROHM ROHM ROHM ROHM ROHM ROHM ROHM ROHM ROHM ROHM ROHM ROHM ROHM ROHM ROHM ROHM ROHM ROHM ROHM ROHM ROHM ROHM ROHM ROHM ROHM ROHM 6/18 Designation R54 R57 R58 R59 R60 R61 R62 C1 C2 C3 C4 C6 C7 C8 C10 C11 C12 C13 C14 C15 C18 C21 C23 C24 C26 C28 C31 D1 D2 D3 D4 L1 L2 M1 M2 U1 Value 100kΩ 75kΩ 0Ω 100Ω 100Ω 100Ω 100Ω 10uF 10uF 0.01uF 1uF 0.1uF 0.1uF 0.047uF 0.1uF 0.1uF 0.047uF 10uF 0.1uF 10uF(25V) 200uF 100pF 10uF 0.1uF 10uF(25V) 200uF 100pF 2.5uH 2.5uH - Part No. MCR03EZPF1003 MCR03EZPF7502 MCR03EZHJ000 MCR03EZPF1000 MCR03EZPF1000 MCR03EZPF1000 MCR03EZPF1000 CM21B106M06A CM21B106M06A MCH185CN103KB CM105B105K06A MCH185CN104K MCH185CN104K MCH185CN473K MCH185CN104K MCH185CN104K MCH185CN473K CM21B106M06A MCH185CN104K CT32X5R106K25A 2R5TPE220MF MCH185A101J CM21B106M06A MCH185CN104K CT32X5R106K25A 2R5TPE220MF MCH185A101J PB521S-30 PB521S-30 RSX501L-20 RSX501L-20 CDEP105-2R5MC-32 CDEP105-2R5MC-32 SP8K4(2in1) SP8K4(2in1) BD9535MUV Company ROHM ROHM ROHM ROHM ROHM ROHM ROHM ROHM ROHM ROHM ROHM ROHM ROHM ROHM ROHM ROHM ROHM ROHM ROHM KYOCERA SANYO ROHM ROHM ROHM KYOCERA SANYO ROHM ROHM ROHM ROHM ROHM Sumida Sumida ROHM ROHM ROHM ●Pin Descriptions ・VCC (13pin) This is the power supply pin for IC internal circuits, except the FET driver. The maximum circuit current is 2.0mA. The input supply voltage range is 4.5V to 5.5V. It is recommended that a 0.1uF bypass capacitor be put in this pin. ・EN1/EN2 (4pin/20pin) When EN pin voltage is at least 2.3V, the status of this switching regulator become active. Conversely, the status switches off when EN pin voltage goes lower than 0.8V and circuit current becomes 20uA or less. This pin is also switch pin of SLLMTM. The voltage is 2.3V to 3.8V : forced continuous mode, 4.2V to 5.5V : SLLMTM. These operating modes are changeable to control by power supply system 3.3V or 5V. ・VDD (28pin) This is the power supply pin to drive the LOW side FET. It is recommended that a 1uF bypass capacitor be established to compensate for rush current during the FET ON/OFF transition. ・VREG (8pin) This is the reference voltage output pin. The voltage is 2.5V, with 100uA current ability. It is recommended that a 1uF capacitor be established between VREF and GND. It is available to set VREF by the resistance division value from VREG in case VREF is not set from an external power supply. ・REF1/REF2 (7pin/17pin) This is the setting pin for output voltage of switching regulator. It is so convenient to be synchronized to outside power supply. This IC controls the voltage in the status of VREF1≒Vis-1 or VREF2≒Vis-2. ・ILIM1/ILIM2 (6pin/18pin) BD9535MUV detects the voltage between Is+ pin and Is- pin and limits the output current (OCP). Voltage equivalent to 1/10 of the ILIM voltage is the voltage drop of external current sense resistor. A very low current sense resistor or inductor DCR can also be used for this platform. ・SS1/SS2 (5pin/19pin) This is the adjustment pin to set the soft start/stop time. SS voltage is low during standby status. When EN is ON, the soft start time can be determined by the SS charge current and capacitor between SS-GND. Until SS reaches REF voltage, the output voltage is equivalent to SS voltage. ・VIN (16pin) The duty cycle is determined by input voltage and controls output voltage. In other words, the output voltage is affected by input voltage. Therefore, when VIN voltage fluctuates, the output voltage becomes also unstable. Since the VIN line is also the input voltage of the switching regulator, stability depends on the impedance of the voltage supply. It is recommended to establish a bypass capacitor or CR filter suitable for the actual application. ・FS (9pin) This is the pin to adjust the switching frequency with the resistor. The frequency range is from 200kHz to 600kHz. ・Is+1/Is+2,Is-1/Is-2 (11pin/14pin/10pin/15pin) These pins are connected to both sides of the current sense resistor to detect output current. The voltage drop between Is+ and Is- is compared with the voltage equivalent to 1/10 of ILIM voltage. When this voltage drop hits the specified voltage level, the output voltage is OFF. ・BOOT1/BOOT2 (1pin/23pin) This is the voltage supply to drive the high side FET. The maximum absolute ratings are 35V (from GND) and 7V (from SW). BOOT voltage swings between (VIN+Vcc) and Vcc during active operation. ・HG1/HG2 (29pin/27pin) This is the voltage supply to drive the Gate of the high side FET. This voltage swings between BOOT and SW. High-speed Gate driving for the high side FET is achieved due to the low on-resistance (3 ohm when HG is high, 2 ohm when HG is low) driver. ・SW1/SW2 (31pin/25pin) This is the source pin for the high side FET. The maximum absolute ratings are 30V (from GND). SW voltage swings between VIN and GND. ・LG1/LG2 (29pin/27pin) This is the voltage supply to drive the Gate of the low side FET. This voltage swings between VDD and PGND. High-speed Gate driving for the low side FET is achieved due to the low on-resistance (3 ohm when LG is high, 0.5 ohm when LG is low) driver. ・PGND1/PGND2 (30pin/26pin) This is the power ground pin connected to the source of the low side FET. This is the source pin for low-side FET. It is prepared for each channel to reduce the interference among channels. ・PGOOD1/PGOOD2 (3pin/21pin) This is the monitor pin for output voltage (Is-1/Is-2). When the output voltage is within 10% of setting voltage (REF1/2), High is output. It is open drain pin and connects to other power supply through the pull-up resistance. ・CE1/PCE2 (2pin/22pin) This pin is helpful for using ceramic capacitor as output capacitor. It is stable to use low ESR capacitor (small ripple voltage). ・GND (12pin) This is GND pin for Analog and Digital series. Set the reverse side of IC equivalent to the voltage of this pin. 7/18 ● Explanation of Operation The BD9535MUV is a 2ch synchronous buck regulator controller incorporating ROHM’s proprietary H3REG CONTROLLA control system. When VOUT drops due to a rapid load change, the system quickly restores VOUT by extending the TON time interval. Thus, it serves to improve the regulator’s transient response. Activating the Light Load Mode will also exercise Simple Light Load Mode (SLLM) control when the load is light, to further increase efficiency. 3 TM H Reg control (Normal operation) When VOUT falls to a threshold voltage (REF), the drop is detected, activating the H3REG CONTROLLA system. Is-(VOUT) REF tON= REF 1 × VIN f [sec]・・・(1) HG HG output is determined by the formula above. LG (VOUT drops due to a rapid load change) When VOUT drops due to a rapid load change, and the voltage remains below REF after the programmed tON time interval has elapsed, the system quickly restores VOUT by extending the tON time, improving the transient response. Is-(VOUT) REF Io tON+α HG LG Is-(VOUT) REF In SLLM (SLLM=0V), SLLM function is operated when LG pin is OFF and the coil current is lower than 0A (the current goes from VOUT to SW). And it stops to output next HG. When VOUT goes lower than REF voltage again, the status of HG is ON. HG LG 0A VIN VIN REF H3RegTM R CONTROLLA S SLLMTM Q Driver VOUT Circuit Is-(VOUT) VCC EN EN 0～2.3V 2.3～3.8V 4.2～5.5V 4V 8/18 Output OFF ON ON Operating mode Forced continuous mode SLLMTM ● Timing Chart • Soft Start Function Soft start is exercised with the EN pin set high. Current control takes effect at startup, enabling a moderate output voltage “ramping start.” Soft start timing and incoming current are calculated with formulas (2) and (3) below. EN TSS(ON) SS Soft start time TSS(ON)= REF×Css [sec] ・・・(2) 2μA(typ) VOUT rush current IIN IIN= Co×VOUT Tss [A] ・・・(3) (Css: Soft start capacitor; Co: Output capacitor) • Soft Stop Function Soft stop is exercised with the EN pin set low. Current control takes effect at startup, enabling a moderate output voltage. Soft start timing and incoming current are calculated with formulas (4) below. EN TSS(OFF) 2VBE SS 0.1V Soft stop time Is(VOUT) Spontaneous discharge (It is determined by load and output capacitor.) TSS(OFF)= (REF+2VBE-0.1)×Css 2μA(typ) Tdelay [sec] ・・・(4) VBE = 0.6[V] (typ) Tdelay = 2VBE×CSS 2μA(typ) [sec] ・・・(5) ・Synchronous operation with other power supply 3.3V(other power supply) These power supply sequences are realized to connect SS pin to other power supply output through the resistance (10kΩ). 1.8V (BD9535 output 1) 1.2V (BD9535 output 2) 9/18 ●Timing chart ・Over current protection circuit tON tON tMAX During the normal operation, when VOUT becomes less than REF Voltage, HG becomes High during the time TON. However, when inductor current exceeds ILIMIT threshold, HG becomes OFF. After MAX ON TIME, HG becomes ON again if the output voltage is lower than the specific voltage level and IL is lower than ILIMIT level. tON HG LG ILIMIT IL ・Timer Latch Type Short Circuit Protection Is(VOUT) When output voltage (Is-) falls to REF×0.7 or less, SCP comparator inside IC is exercised. If the status of High is continued 1ms or more (programmed time inside IC), the IC goes OFF. It can be restored either by reconnecting the EN pin or disabling UVLO. REF×0.7 Spontaneous discharge 1msec SCP EN /UVLO ・Output Over Voltage Protection Is(VOUT) REF×1.2 160mV When output rise to or above REF×1.2, output over voltage protection is exercised, and low side FET goes up maximum for reducing output. （ LG=High, HG=Low）. When output falls, it returns to the standard mode. HG LG Switching 10/18 ● External Component Selection 1. Inductor (L) selection The inductor value is a major influence on the output ripple current. As formula (5) below indicates, the greater the inductor or the switching frequency, the lower the ripple current. (VIN-VOUT)×VOUT ΔIL= [A]・・・(6) L×VIN×f The proper output ripple current setting is about 30% of maximum output current. ΔIL=0.3×IOUTmax. [A]・・・(7) ΔIL VIN IL VOUT L L= Co (VIN-VOUT)×VOUT L×VIN×f [H]・・・(8) (ΔIL: output ripple current; f: switch frequency) Output ripple current ※Passing a current larger than the inductor’s rated current will cause magnetic saturation in the inductor and decrease system efficiency. In selecting the inductor, be sure to allow enough margin to assure that peak current does not exceed the inductor rated current value. ※To minimize possible inductor damage and maximize efficiency, choose a inductor with a low (DCR, ACR) resistance. 2.Output Capacitor (CO) Selection When determining the proper output capacitor, be sure to factor in the equivalent series resistance required to smooth out ripple volume and maintain a stable output voltage range. Output ripple voltage is determined as in formula (9) below. VIN VOUT L ΔVOUT=ΔIL×ESR+ESL×ΔIL/TON・・・(9) ESR (ΔIL: Output ripple current; ESR: CO equivalent series resistance, ESL: CO equivalent series inductance) ESL Co ※ In selecting a capacitor, make sure the capacitor rating allows sufficient margin relative to output voltage. Note that a lower ESR can minimize output ripple voltage. Output capacitor Please give due consideration to the conditions in formula (10) below for output capacity, bear in mind that output rise time must be established within the soft start time frame. Co≦ TSS×(Limit-IOUT) VOUT ・・・(10) Tss: Soft start time Limit: Over current detection IOUT: Output current Note: Improper capacitor may cause startup malfunctions. 3. Input Capacitor (Cin) Selection The input capacitor selected must have low enough ESR resistance to fully support large ripple output, in order to prevent extreme over current. The formula for ripple current IRMS is given in (11) below. VIN Cin VOUT L Co IRMS=IOUT× √VOUT (VIN-VOUT) VIN Where VIN=2×VOUT, IRMS= IOUT 2 Input Capacitor A low ESR capacitor is recommended to reduce ESR loss and maximize efficiency. 11/18 [A]・・・(11) 4. MOSFET Selection Loss on the main MOSFET VIN Pmain=PRON+PGATE+PTRAN main switch = VOUT VOUT ×RON×IOUT2+Qg×f×VDD+ VIN 2 VIN ×Crss×IOUT×f IDRIVE ・・・(12) L (Ron: On-resistance of FET; Qg: GATE total charge f: Switching frequency, Crss: FET inverse transfer function; IDRIVE: Gate peak current) Co synchronous switch Loss on the synchronous MOSFET Psyn=PRON+PGATE = VIN-VOUT VIN ×RON×IOUT2+ Qg×f×VDD ・・・(13) 5. Setting Detection Resistance VIN L The over current protection function detects the output ripple current peak value. This parameter (setting value) is determined as in formula (14) below. R IL VOUT ILMIT= Co VILIM×0.1 R [A]・・・(14) (VILIM: ILIM voltage; R: Detection resistance) Is+ Is+ Current limit VIN When the over current protection is detected by DCR of coil L, this parameter (setting value) is determined as in formula (14) below. IL L r RL C VOUT ILMIT=VILIM×0.1× Co (RL= L r×C r×C L [A]・・・(15) ) (VILIM:ILIM voltage RL: the DCR value of coil) Is+ Is+ Current limit IL detect point As soon as the voltage drop between Is+ and Is- generated by the inductor current becomes specific threshold, the gate voltage of the high side MOSFET becomes low. Since the peak voltage of the inductor ripple current is detected, this operation can sense high current ripple operation caused by inductance saturated rated current and lead to high reliable systems. ILIMIT 0 t 12/18 6. Setting frequency 【1ch】 The On Time (TON) at steady state is determined by resistance value connected to FS pin. But actually SW rising time and falling time come up due to influence of the external MOSFET gate capacity or switching speed and TON is increased. The frequency is determined by the following formula after TON, input current and the REF voltage are fixed. 700 VIN=3V 5V 7V 12V 19V Frequency [kHz] 600 500 400 300 F= VIN×TON 200 100 0 50 100 150 200 RFS[kΩ] 【2ch】 900 800 VIN=3V 5V 7V 12V 19V 700 600 500 400 300 200 100 VREF=1.8V 0 0 50 100 150 ・・・(15) Consequently, total frequency becomes lower than the formula above. TON is also influenced by Dead Time around the output current 0A area in continuous mode. This frequency becomes lower than setting frequency. It is recommended to check the steady frequency in large current area (at the point where the coil current doesn’t back up). VREF=1.8V 0 Frequency [kHz] REF 200 RFS[kΩ] 13/18 7. Setting standard voltage (REF) VIN REF 3 R TM H Reg CONTROLLA It is available to synchronize setting the reference voltage (REF) with outside supply voltage [V] by using outside power supply voltage. Q S Outside voltage VOUT VREG It is available to set the reference voltage (REF) by the resistance division value from VREG in case it is not set REF from an external power supply. VIN R1 REF R H3RegTM CONTROLLA Q S R2 REF= R2 R1+R2 ×VREG [V]・・・(17) VOUT 8. Setting output voltage This IC is operated that output voltage is REF≒Is-(VOUT). And it is operated that output voltage is feed back to FB pin in case the output voltage is 0.7V to 2.0V. Actually, the average value of ripple voltage is added to output voltage. Output voltage = REF + VIN REF R H3RegTM 1 2 ×ΔIL×ESR・・・(18) VIN SLLMTM Q Output voltage CONTROLLA Driver S SLLM Circuit ESR Is-(VOUT) In case the output voltage range is 0.7V to 2.0V. It is operated that the resistance division value of the output voltage is feed back to Is-pin in case the output voltage is more than 2.0V. output voltage = R1+R2 R2 × REF + 1 2 ×ΔIL×ESR・・・(19) In this time, the frequency is also amplified by power of the resistance division. It is determined as in formula (20) below. Frequency= R1+R2 R2 ×(frequency determined by REF) [Hz]・・・(20) VIN REF VIN H3RegTM R CONTROLLA S Q SLLM TM Output Driver SLLM ESR Circuit Is-(VOUT) R1 In case the output voltage range is more than 2.0V. 14/18 R2 ●I/O Equivalent Circuit 1pin, 23pin (BOOT1/2) 2pin, 22pin (CE1/2) 3pin, 21pin (PGOOD1/2) 300Ω HG SW 4pin, 20pin (EN1/2) 5pin, 19pin (SS1/2) 6pin, 18pin (ILIM1/2) 8pin (VREG) 9pin (FS) 430KΩ 7pin, 17pin (REF1/2) 1.2MΩ 10pin, 15pin (Is-1/2) 24pin, 32pin (HG1/2) BOOT 400KΩ 11pin, 14pin (Is+1/2) 16pin (VIN) 25pin, 31pin (SW1/2) 27pin, 29pin (LG1/2) BOOT VDD BOOT HG 300KΩ 100KΩ 300KΩ 300KΩ SW 300KΩ 15/18 ●Operation Notes 1. Absolute maximum ratings An excess in the absolute maximum ratings, such as supply voltage, temperature range of operating conditions, etc., can break down the devices, thus making impossible to identify breaking mode, such as a short circuit or an open circuit. If any over rated values will expect to exceed the absolute maximum ratings, consider adding circuit protection devices, such as fuses. 2. Connecting the power supply connector backward Connecting of the power supply in reverse polarity can damage IC. Take precautions when connecting the power supply lines. An external direction diode can be added. 3. Power supply lines Design PCB layout pattern to provide low impedance GND and supply lines. To obtain a low noise ground and supply line, separate the ground section and supply lines of the digital and analog blocks. Furthermore, for all power supply terminals to ICs, connect a capacitor between the power supply and the GND terminal. When applying electrolytic capacitors in the circuit, not that capacitance characteristic values are reduced at low temperatures. 4. GND voltage The potential of GND pin must be minimum potential in all operating conditions. 5. Thermal design Use a thermal design that allows for a sufficient margin in light of the power dissipation (Pd) in actual operating conditions. 6. Inter-pin shorts and mounting errors Use caution when positioning the IC for mounting on printed circuit boards. The IC may be damaged if there is any connection error or if pins are shorted together. 7. Actions in strong electromagnetic field Use caution when using the IC in the presence of a strong electromagnetic field as doing so may cause the IC to malfunction. 8. ASO When using the IC, set the output transistor so that it does not exceed absolute maximum ratings or ASO. 9. Thermal shutdown circuit The IC incorporates a built-in thermal shutdown circuit (TSD circuit). The thermal shutdown circuit (TSD circuit) is designed only to shut the IC off to prevent thermal runaway. It is not designed to protect the IC or guarantee its operation. Do not continue to use the IC after operating this circuit or use the IC in an environment where the operation of this circuit is assumed. TSD on temperature [°C] (typ.) Hysteresis temperature [°C] (typ.) BD9535MUV 175 15 10. 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. Always turn the IC's power supply off before connecting it to or removing it from a jig or fixture during the inspection process. Ground the IC during assembly steps as an antistatic measure. Use similar precaution when transporting or storing the IC. 16/18 11. 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, creating a parasitic diode or transistor. For example, the relation between each potential is as follows: 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 can occur inevitable in the structure of the IC. The operation of parasitic diodes can result in mutual interference among circuits, operational faults, or physical damage. Accordingly, methods by which parasitic diodes operate, such as applying a voltage that is lower than the GND (P substrate) voltage to an input pin, should not be used. Resistor Transistor (NPN) Pin A Pin B Pin B B C E Pin A N P + N P P + N Parasitic element N P P substrate P C + N E Parasitic element P substrate GND Parasitic element B N P+ Parasitic element GND GND GND Other adjacent elements Fig. 13 Example of IC structure 12. Ground Wiring Pattern 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 ground potential of application 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 pattern of any external components, either. ● Power Dissipation [mW] 1000 980mW mounted on glass epoxy PCB 70ｍｍ×70mm×1.6mm θj-a=127.0℃/W Power Dissipation (Pd) 800 600 IC unit time θj-a=403.2℃/W 400 310mW 200 0 25 50 75 100 125 150 Ambient temperature (Ta) 17/18 [℃] ● Type Designations (Selections) for Ordering B D Product name ・BD9535 9 5 3 5 M U Package type ・MUV = V ― E 2 Taping type name E2= Embossed carrier tape VQFN032V5050 VQFN032V5050 <Tape and Reel information> <Dimension> Tape Embossed carrier tape(with dry pack) Quantity 2500pcs E2 Direction of feed (The direction is the 1pin of product is at the upper left when you hold reel on the left hand and you pull out the tape on the right hand) 1234 1234 1pin 1234 Reel 1234 1234 1234 (Unit:mm) Direction of feed ※When you order , please order in times the amount of package quantity. Catalog No.08T453A '08.9 ROHM © Appendix 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. 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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 your nearest sales office. ROHM Customer Support System www.rohm.com Copyright © 2008 ROHM CO.,LTD. THE AMERICAS / EUROPE / ASIA / JAPAN Contact us : webmaster@ rohm.co. jp 21 Saiin Mizosaki-cho, Ukyo-ku, Kyoto 615-8585, Japan TEL : +81-75-311-2121 FAX : +81-75-315-0172 Appendix1-Rev3.0