High Performance Regulators for PCs Nch FET Ultra LDO Controllers for PC Chipsets BD3504FVM,BD3500FVM,BD3501FVM,BD3502FVM No.10030EAT29 Description The BD3500/01/02/04FVM is an ultra-low dropout linear regulator controller for chipset that can achieve ultra-low voltage input to ultra-low voltage output. By using N-MOSFET for external power transistor, the controller can be used at ultra-low I/O voltage difference up to voltage difference generated by ON resistance. In addition, because best suited power transistor can be chosen in accord with the output current, downsizing and cost reduction of the set can be achieved. Because by reducing the I/O voltage difference, large current output is achieved and conversion loss can be reduced, switching power supply can be replaced. BD3500/01/02/04FVM does not need any choke coil, diode for rectification and power transistor which are required for switching power supply, total cost of the set can be reduced and compact size can be achieved for the set. Using external resistors, optional output from 0.65V to 2.5V can be set. In addition, since voltage output start-up time can be adjusted by using the NRCS terminal, it is possible to flexibly meet the power supply sequence of the set. Features 1) Reduced rush current by NRCS 2) Built-in driver for external Nch h transistor 3) Adoption of MSOP8 package: 2.9 x 4.0 x 0.9 (mm) 4) Built-in timer latch short protection circuit 5) Built-in low input maloperation prevention circuit 6) Output voltage variable type 7) Built-in overheat protection circuit Applications Mobile PC, desktop PC, digital home appliances Line up matrix Parameter BD3500FVM BD3501FVM BD3502FVM BD3504FVM 1.8V (Fix) 1.5V (Fix) 1.2V (Fix) Variable(0.652.5V) (Independent Setting) (Independent Setting) (Independent Setting) (Independent Setting) (Independent Setting) (Independent Setting) VIN UVLO Hysterisis Hysterisis Hysterisis (Same Timer Latch) (Same NRCS) Detected at start-up only (set by external resistor) External FET GATE Drive Current +1/-3mA +1/-3mA +1/-3mA Output Voltage NRCS (Soft start) Timer latch short protection circuit www.rohm.com (c) 2010 ROHM Co., Ltd. All rights reserved. 1/16 +3/-3mA 2010.05 - Rev.A Technical Note BD3504FVM,BD3500FVM,BD3501FVM,BD3502FVM Absolute maximum ratings (Ta=25) BD3500/01/02FVM Parameter Input Voltage Symbol Ratings Unit VCC 7 *1 V Drain Voltage (VIN) VIN 7 V Enable Input Voltage Ven 7 V Power Dissipation Pd 437.5 *2 mW Operating Temperature Range Topr -10+100 Storage Temperature Range Tstg -55+150 Tjmax +150 Symbol Ratings Unit VCC 7 *3 V Maximum Junction Temperature *1 However, not exceeding Pd. *2 Pd derating at 3.5mW/ for temperature above Ta=25 BD3504FVM Parameter Supply Voltage Drain Voltage VD 7 V Enable Input Voltage Ven 7 V Power dissipation Pd 437.5 *4 mW Operating temperature range Topr -10+100 Storage temperature range Tstg -55+150 Tjmax +150 Maximum Junction Temperature *3 However, not exceeding Pd. *4 Pd derating at 3.5mW/ for temperature above Ta=25 Recommended operating conditions BD3500/01/02FVM Parameter Symbol Ratings VCC Drain Voltage(VIN) VIN Vox1.15 5.5 V Enable Input Voltage Ven -0.3 5.5 V CNRCS 0.001 1 F CSCP 0.001 1 F Supply Voltage Capacitor on NRCS Terminal Capacitor on SCP Terminal MAX 5.5 Unit MIN 4.5 V No radiation-resistant design is adopted for the present product. BD3504FVM Parameter Symbol Ratings VCC Drain Voltage VD 0.65 5.5 V Enable Input Voltage Ven -0.3 5.5 V CNRCS 0.001 1 F VOUT 0.65 2.5 V Supply Voltage Capacitor in NRCS pin Output Voltage MAX 5.5 Unit MIN 4.5 V No radiation-resistant design is adopted for the present product. www.rohm.com (c) 2010 ROHM Co., Ltd. All rights reserved. 2/16 2010.05 - Rev.A Technical Note BD3504FVM,BD3500FVM,BD3501FVM,BD3502FVM Electrical characteristics (unless otherwise noted, Ta=25 VCC=5V Vin=3.3V Ven=3V) BD3500FVM/BD3501FVM/BD3502FVM Standard Value Parameter Symbol Unit MIN TYP MAX Bias Current ICC - 0.8 1.6 mA Shut Down Mode Current IST - 0 10 A Ven=0V Output Voltage 1 (BD3500FVM) Vo1 1.782 1.800 1.818 V Io=50mA Output Voltage 1 (BD3501FVM) Vo1 1.485 1.500 1.515 V Io=50mA Output Voltage 1 (BD3502FVM) Vo1 1.188 1.200 1.212 V Io=50mA Output Voltage 2 (BD3500FVM) Vo2 1.746 1.800 1.854 V Output Voltage 2 (BD3501FVM) Vo2 1.455 1.500 1.545 V Output Voltage 2 (BD3502FVM) Vo2 1.164 1.200 1.236 V Condition Vcc=4.5V to 5.5V ,Io=0 to 3A Ta=-10 to 100() Vcc=4.5V to 5.5V ,Io=0 to 3A Ta=-10 to 100() Vcc=4.5V to 5.5V ,Io=0 to 3A Ta=-10 to 100() Line Regulation Reg.l - 0.1 0.5 %/V VCC=4.5V to 5.5V Load Regulation Reg.L - 0.5 10 mV Io=0 to 3A High Level Enable Input Voltage Enhi 2 - Vcc V Low Level Enable Input Voltage Enlow -0.3 - 0.8 V Ien - 7 10 A Ven=3V NRCS Charge Current Inrcs 14 20 26 A Vnrcs=0.5V,VCC=4.5V to 5.5V Ta=-10 to 100 () NRCS Standby Voltage Vnrcs - 0 50 mV Ven=0V IFB - 0.7 1.2 mA Ven=3V FBSTB 150 - - mA Ven=0V,VFB=1V MOSFET Driver Source Current IGSO 0.5 1 1.5 mA VFB=Vo-0.1V,G=Vo+1V MOSFET Driver Sink Current IGSI 2 3 4 mA VFB=Vo+0.1V,G=Vo+1V VccUVLO 4.2 4.35 4.5 V Vcchys 100 160 220 mV VINUVLO Vox1.05 Vox1.1 Vox1.15 V VINhys 100 160 220 mV VIN:Sweep down SCP Charge Current Iscpch 14 20 26 A VSCP=0.5V,VCC=4.5V to 5.5V Ta=-10 to 100 () SCP Discharge Current IscpDi 0.5 - - mA VSCP=0.5V SCP Threshold Voltage Vscpth 1.2 1.3 1.4 V Short Detect Voltage Vscp Vox0.6 Vox0.7 Vox0.8 V SCP Stand-by Voltage VSTB - 0 50 mV [Enable] Enable Pin Input Current [NRCS] [Voltage Feed Back] VFB Input Bias Current VFB Standby Current [Output MOSFET Driver] [UVLO] VCC UVLO VCC UVLO Hysteresis VIN UVLO VIN UVLO Hysteresis Vcc:Sweep up Vcc:Sweep down VIN:Sweep up [SCP] () Design Guarantee www.rohm.com (c) 2010 ROHM Co., Ltd. All rights reserved. 3/16 2010.05 - Rev.A Technical Note BD3504FVM,BD3500FVM,BD3501FVM,BD3502FVM Electrical characteristics (unless otherwise noted, Ta=25 VCC=5V VIN=3.3V Ven=3V. R1=R1'=, R2=R2'=0) BD3504FVM Standard Value Parameter Symbol Unit Condition MIN TYP MAX Bias Current ICC - 0.85 1.7 mA Shut Down Mode Current IST - 0 10 A Ven=0V Feed Back Voltage 1 VFB1 0.643 0.650 0.657 V Io=50mA Feed Back Voltage 2 VFB2 0.630 0.650 0.670 V Vo - 1.20 - V Output Voltage Vcc=4.5V to 5.5V , Ta=-10 to 100() R1=R1'=3.9k, R2=R2'=3.3K Line Regulation Reg.l - 0.1 0.5 %/V VCC=4.5V to 5.5V Load Regulation Reg.L - 0.5 10 mV Io=0 to 3A [Enable] High Level Enable Input Voltage Enhi 2 - Vcc V Low Level Enable Input Voltage Enlow -0.3 - 0.8 V Ien - 7 10 A IFB - 80 - nA VS Input Bias Current ISBIAS - 1.2 2.4 mA VS Standby Current ISSTB 150 - - mA VS=1V Ven=0V MOSFET Driver Source Current IGSO 2 3 4 mA VFB=0.6V,VGATE=2.5V MOSFET Driver Sink Current IGSI 2 3 4 mA VFB=0.7V,VGATE=2.5V VccUVLO 4.20 4.35 4.50 V Vcchys 100 160 220 mV VDUVLO Vox0.6 Vox0.7 Vox0.8 V Ivd - 0 - nA Enable pin Input Current Ven=3V [Voltage Feed Back] VFB Input Bias Current [Source Voltage] [Output MOSFET Driver] [UVLO] VCC UVLO VCC UVLO Hysterisis VD UVLO Vcc:Sweep up Vcc:Sweep down VD:Sweep up [Drain Voltage Sensing] VD Input bias Current [NRCS/SCP] NRCS Charge Current Inrcs 14 20 26 A VNRCS=0.5V SCP Charge Current Iscpch 14 20 26 A VNRCS=0.5V SCP Discharge Current IscpDi 0.3 - - mA VNRCS=0.5V SCP Threshold Voltage Vscp 1.2 1.3 1.4 V Short Detect Voltage Voscp Vox0.3 Vox0.35 Vox0.4 V NRCS Stand-by Voltage VSTB - - 50 mV () Design Guarantee www.rohm.com (c) 2010 ROHM Co., Ltd. All rights reserved. 4/16 2010.05 - Rev.A Technical Note BD3504FVM,BD3500FVM,BD3501FVM,BD3502FVM Reference Data 1.40 1.00 1.800 0.80 1.795 1.20 0.60 1.790 0.60 Vo(V) 0.80 ICC(mA) I(uA) 1.00 0.40 1.780 0.40 0.20 0.20 0.00 -60 -10 40 Ta( ) 90 140 1.775 0.00 4.5 4.7 4.9 5.1 VCC(V) 5.3 1.770 5.5 -10 21.5 11 250 21 10 200 20.5 ISCP(uA) 300 9 150 100 19.5 7 50 19 0 50 75 100 Ta( ) 125 0 150 Fig.4 Ta-IEN 0.2 0.4 0.6 0.8 Vout(mV) 65 90 20 8 6 40 Ta() Fig.3 Ta-Vo 12 25 15 Fig.2 ICC-VCC IS(mA) IEN(uA) Fig.1 Ta-ISTB Vo(V) 1.785 1 1.2 18.5 -60 Fig.5 VS Discharge Current -10 40 Ta( ) 90 140 Fig.6 Ta-ISCP 1.26 1.255 VBG(V) 1.25 VCC VCC VIN VIN EN EN 1.245 1.24 VOUT 1.235 1.23 -60 VOUT (1.075V ) -10 40 Ta( ) 90 (1.075V ) 140 VCC VIN VIN Fig 9. Input Sequence 2 VIN Fig.8 Input Sequence 1 EN Fig.7 Ta-Vo VOUT (1.075V ) EN EN IOUT (1A/div) VOUT VOUT (1.075V ) Fig.10 Input Sequence 3 Vcc www.rohm.com (c) 2010 ROHM Co., Ltd. All rights reserved. Fig.11 Input Sequence 4 (Only BD3504FVM) 5/16 Fig.12 Transient Response 03A(0.6A/s)V=30mV 2010.05 - Rev.A Technical Note BD3504FVM,BD3500FVM,BD3501FVM,BD3502FVM VOUT (1.075V ) VOUT (BD3502FVM) VOUT (BD3502FVM) IOUT (1A/div) IOUT (1A/div) IOUT (1A/div) Fig.13 Transient Response 30A(0.6A/s)V=20mV Fig.14 Transient Response 03A(0.6A/s)V=21mV Fig.15 Transient Response 30A(0.6A/s) V=17mV VOUT (BD3501FVM) VOUT (BD3501FVM) VOUT (BD3500FVM) IOUT (1A/div) IOUT (1A/div) IOUT (1A/div) Fig.16 Transient Response 03A(0.6A/s) V=42mV Fig.17 Transient Response 30A(0.6A/s) V=27mV Fig.18 Transient Response 03A(0.6A/s) V=44mV VOUT (BD3500FVM) VOUT (1.05V ) VOUT (1.05V ) IOUT (1A/div) IOUT (1A/div) IOUT Fig.19 Transient Response 30A(0.6A/s) V=26mV www.rohm.com (c) 2010 ROHM Co., Ltd. All rights reserved. Fig.20 Transient Response 03A(0.6A/s) V=44mV 6/16 Fig.21 Transient Response 30A(0.6A/s) V=23mV 2010.05 - Rev.A Technical Note BD3504FVM,BD3500FVM,BD3501FVM,BD3502FVM Block Diagram BD3500FVM/BD3501FVM/BD3502FVM VCC VCC 4 1 NRCS NRCS Enabe EN 8 UVLO2 5 VREF G VREF 7 VREF Vo VFB 6 TSD SCP UVLO1 UVLO2 Thermal Protection VREF TSD VIN VIN UVLO1 Reference Block SCP 3 2 SCP GND BD3504FVM VCC VCC 4 VD UVLO2 Enable UVLO1 EN 3 Reference Block VD UVLO LATCH Thermal Protection UVLO1 NRCS EN G 7 6 R2 5 VFB R1 SCP 0.65V NRCS 2 NRCS www.rohm.com Vo VS TSD SCP UVLO1 UVLO2 EN 1 (c) 2010 ROHM Co., Ltd. All rights reserved. R1' VREF SCP TSD VIN 8 NRCS 0.65V 0.65V R2' 7/16 GND 2010.05 - Rev.A Technical Note BD3504FVM,BD3500FVM,BD3501FVM,BD3502FVM Pin Configration and Pin Function BD3500FVM/BD3501FVM/BD3502FVM Pin Configration NRCS 1 8 EN GND 2 7 G 3 6 SCP VCC 4 5 VFB VIN Pin Function Pin Pin No. Name PIN FUNCTION 1 NRCS 2 GND Ground pin 3 SCP Timer latch setup for Short Circuit Protection 4 VCC Power Source 5 VIN Drain Voltage Sense 6 VFB Output Voltage Feedback 7 G 8 EN (Non Rush Current on Start up) time setup MOSFET Driver Output Enable BD3504FVM Pin Configration Pin Function Pin Pin No. Name NRCS 1 8 VD GND 2 7 G EN 3 VCC 4 www.rohm.com (c) 2010 ROHM Co., Ltd. All rights reserved. 6 5 VS VFB PIN FUNCTION NRCS (Non Rush Current on Start up) time setup. Timer latch setup for Short Circuit Protection operating time set up Pin. Ground Pin 1 NRCS 2 GND 3 EN 4 VCC Power Source 5 VFB Output Voltage Feedback 6 VS Source Voltage Pin 7 G MOSFET Driver Output 8 VD 8/16 Enable Pin Drain Voltage Sense 2010.05 - Rev.A BD3504FVM,BD3500FVM,BD3501FVM,BD3502FVM Technical Note Pin Function Descriptions VCC BD3500/01/02/04FVM has an independent power input pin for an internal circuit operation of IC. This is used for bias of IC internal circuit and external N-MOSFET. The voltage used of VCC terminal is 5.0V and maximum current is 1.7 mA. It is recommended to connect a bypass capacitor of 0.1 F or so to VCC pin. EN With an input of 2.0 volts or higher, the EN terminal turns to "High" level and VOUT is outputted. At 0.8V or lower, it detects "Low" level and VOUT is turned OFF and simultaneously, the discharge circuit inside the VS terminal is activated and lowers output voltage (150 mA (Min) when VFB//VS=1V and VEN=0V). VIN(BD3500/01/02FVM) The VIN terminal is a drain voltage detection terminal of external N-MOSFET. In the event that the VIN terminal is lower than 1.1 times the output set voltage, output is turned OFF to prevent low-input maloperation. VD(BD3504FVM only) The VD terminal is a drain voltage detection terminal of external N-MOSFET. In the event that drain voltage (VIN) is low, output voltage is turned OFF to prevent low-input maloperation. The reset voltage (VDUVLO) of drain voltage low-input maloperation prevention circuit is determined by the following equation: VDUVLO=VFBx0.7 x R1'+R2 R1 ' In the event that the maloperation prevention set resistance at the time of low-input drain voltage is set to a resistance value same as output voltage set resistor (R1 = R1', R2 = R2'), low-input maloperation prevention (UVLO) is reset when drain voltage (VIN) reaches 70% of the output voltage. UVLO detects only at the startup of the EN terminal. VFB(BD3504FVM only) The VFB terminal is a terminal to decide output voltage and is determined by the following equation: R1'+R2 VOUT=VFBx R1' VFB is controlled to achieve 0.65 V (typ.). NRCS terminal he NRCS terminal is a constant current output terminal, and operates as Soft-Start ... during start-up SCP-Delay ... after start-up (BD3504FVM only). How to set Soft-Start of NRCS terminal The output voltage startup time (TNRCS) is determined by the time when the NRCS terminal reaches VFB (0.65V). During start-up, the NRCS terminal serves as a constant current source (INRCS) of 20 A (Typ.) output, and charges capacitor (CNRCS) externally connected. By changing over to internal reference voltage (0.65V) when the NRCS terminal reaches 0.65V, output voltage (VOUT) is fixed. How to set NRCS terminal short protection Delay (BD3504FVM only) BD3504FVM has short protection (SCP) activated when output voltage becomes VOUT x 0.35 (typ.) or lower. The time when short protection is activated until latching takes place (TSCP) is determined by the following equation: Tscp = CNRCS x Voscp / Iscp When short protection is activated, the NRCS terminal provides 20 A (typ.) constant current output (lscp), and charges the capacitor (CNRCS) externally connected. When the NRCS terminal reaches 1.3V (Voscp), latch operation is carried out and output voltage is turned OFF. SCP(BD3500/01/02FVM) BD3500/01/02FVM has short protection (SCP) activated when output becomes 70% or lower than the set voltage. The time when short protection is activated until latching takes place (TSCP) is determined by the following equation: Tscp = CNRCS x Voscp / Iscp When short protection is activated, the NRCS terminal provides 20 A (typ.) constant current output (lscp), and charges the capacitor (CNRCS) externally connected. When the NRCS terminal reaches 1.3V (Voscp), latch operation is carried out and output voltage is turned OFF. VFB//VS (BD3500FVM/BD3501FVM/BD3502FVM//BD3504FVM) VFB//VS terminal is a source voltage detection terminal of external N-MOSFET. VFB//VS terminal has the internal discharge circuit activated to lower output voltage when EN becomes a Low level or various protection circuits (TSD, SCP, UVLO) are activated. G G terminal is a gate drive terminal of external N-MOSFET. Because the output voltage range of G terminal is up to 5V (VCC), it is necessary to use N-MOSFET whose threshold is lower than "5V-VOUT." In addition, by incorporating a RC snubber circuit to the G terminal, phase allowance of loop gain can be increased and the terminal can accommodate ceramic capacitors. www.rohm.com (c) 2010 ROHM Co., Ltd. All rights reserved. 9/16 2010.05 - Rev.A Technical Note BD3504FVM,BD3500FVM,BD3501FVM,BD3502FVM Application circuit Ven 1 8 2 7 3 6 C4 VIN C3 C2 C5 4 Vcc + 5 C1 R2' 1 VIN 8 R1' C3 2 7 3 6 R2 Ven 4 Vcc C2 C4 + 5 R1 C1 Directions for pattern layout of PCB Because a VIN input capacitor causes impedance to drop, mount it as close to the VIN terminal as possible and use thick wiring patterns. In the event that it causes the wire to come in contact with the inner-layer ground plane, use a plurality of through holes. Because the NRCS terminal is analog I/O, take care to noise. In particular, high-frequency noise of GND may cause IC maloperation through capacitors. It is recommended to connect GND of NRCS capacitor to IC GND terminal at one point. The VFB terminal is an output voltage sense line. Effects of wiring impedance can be ignored by sensing the output voltage from the load side, but increased sense wiring causes VFB to be susceptible to noise, to which care must be taken. Because the GND terminal is GND to be used in analog circuit inside BD3501/02/04FVM, connect it at one point to inner-layer GND of substrate by as short pattern as possible. Arrange a bypass capacitor across VCC and GND as close as possible so that a loop can be minimized. The G terminal is a terminal for gate drive. If long wiring is inevitable, increase the pattern width and lower impedance. Heat generated in the output transistor can be calculated by: (VIN - VOUT) x Io(Max) Design heat generation not to exceed the guarantee temperature of transistor. Connect the output capacitor with thick short wiring so that the impedance is lowered. Connect capacitor GND to inner-layer GND plane by a plurality of through holes. www.rohm.com (c) 2010 ROHM Co., Ltd. All rights reserved. 10/16 2010.05 - Rev.A Technical Note BD3504FVM,BD3500FVM,BD3501FVM,BD3502FVM Evaluation Board (BD3500/01/02FVM) BD350XFVM Evaluation Board Circuit BD350XFVM Evaluation Board Application Components U1 VCC BD350XFVM 8 S1 3 1 C2 EN VIN C4 SCP G VFB 4 7 U2 NRCS C3 VCC VIN 5 Value Company Parts Name U1 - ROHM BD3500/01/02FVM U2 NMOS ROHM RTW060N03 C1 1F MURATA GRM18 series C2 0.01F MURATA GRM18 series Part No Value Company Parts Name C3 0.01F MURATA GRM18 series C4 10F MURATA GRM21 series C5 220F SANYO,etc 2R5TPE220MF VOUT 6 C5 VCC C1 2 Part No GND BD350XFVM Evaluation Board Layout Evaluation Board (BD3504FVM) BD3504FVM Evaluation Board Circuit BD3504FVM Evaluation Board Application Components GND U1 Part No VTTS BD3504FVM VCC VD 3 S1 1 C2 VCC R1' G VS 4 VCC VFB C1 2 R2' 8 EN NRCS Bottom Layer TOP Layer Silk Screen VIN C3 7 U2 6 5 GND R2 VOUT C4 R1 Value Company Parts Name U1 - ROHM BD35304FVM U2 NMOS ROHM RTW060N03 R1 3.9K ROHM MCR03EZPF3901 R1' 3.3K ROHM MCR03EZPF3301 R2 3.9K ROHM MCR03EZPF3901 Part No Value Company Parts Name R2' 3.3K ROHM MCR03EZPF3301 C1 1F MURATA GRM18 series C2 0.01F MURATA GRM18 series C3 10F MURATA GRM21 series C4 220F SANYO,etc 2R5TPE220MF BD3504FVM Evaluation Board Layout Silk Screen www.rohm.com (c) 2010 ROHM Co., Ltd. All rights reserved. TOP Layer 11/16 Bottom Layer 2010.05 - Rev.A Technical Note BD3504FVM,BD3500FVM,BD3501FVM,BD3502FVM I/O EQUIVALENCE CIRCUIT BD3500FVM/BD3501FVM/BD3502FVM Vcc Vcc Vcc Vcc Vcc Vcc VI NRCS SCP Vcc Vcc Vcc Vcc EN GATE VFB BD3504FVM Vcc Vcc Vcc Vs VD NRCS Vcc Vcc Vcc EN GATE VFB www.rohm.com (c) 2010 ROHM Co., Ltd. All rights reserved. 12/16 2010.05 - Rev.A Technical Note BD3504FVM,BD3500FVM,BD3501FVM,BD3502FVM Notes for use 1. Absolute maximum ratings For the present product, thoroughgoing quality control is carried out, but in the event that applied voltage, working temperature range, and other absolute maximum rating are exceeded, the present product may be destroyed. Because it is unable to identify the short mode, open mode, etc., if any special mode is assumed, which exceeds the absolute maximum rating, physical safety measures are requested to be taken, such as fuses, etc. 2. GND potential Bring the GND terminal potential to the minimum potential in any operating condition. 3. Thermal design Consider allowable loss (Pd) under actual working condition and carry out thermal design with sufficient margin provided. 4. Terminal-to-terminal short-circuit and erroneous mounting When the present IC is mounted to a printed circuit board, take utmost care to direction of IC and displacement. In the event that the IC is mounted erroneously, IC may be destroyed. In the event of short-circuit caused by foreign matter that enters in a clearance between outputs or output and power-GND, the IC may be destroyed. 5. Operation in strong electromagnetic field The use of the present IC in the strong electromagnetic field may result in maloperation, to which care must be taken. 6. Built-in thermal shutdown protection circuit The present IC incorporates a thermal shutdown protection circuit (TSD circuit). The working temperature is 175C (standard value) and has a -15 (standard value) hysteresis width. When the IC chip temperature rises and the TSD circuit operates, the output terminal is brought to the OFF state. The built-in thermal shutdown protection circuit (TSD circuit) is first and foremost intended for interrupt IC from thermal runaway, and is not intended to protect and warrant the IC. Consequently, never attempt to continuously use the IC after this circuit is activated or to use the circuit with the activation of the circuit premised. 7. Capacitor across output and GND In the event a large capacitor is connected across output and GND, when Vcc and VIN are short-circuited with 0V or GND for some kind of reasons, current charged in the capacitor flows into the output and may destroy the IC. Use a capacitor smaller than 1000 F between output and GND. 8. Inspection by set substrate In the event a capacitor is connected to a pin with low impedance at the time of inspection with a set substrate, there is a fear of applying stress to the IC. Therefore, be sure to discharge electricity for every process. As electrostatic measures, provide grounding in the assembly process, and take utmost care in transportation and storage. Furthermore, when the set substrate is connected to a jig in the inspection process, be sure to turn OFF power supply to connect the jig and be sure to turn OFF power supply to remove the jig. 9. IC terminal input The present IC is a monolithic IC and has a P substrate and P+ isolation between elements. With this P layer and N layer of each element, PN junction is formed, and when the potential relation is GND>terminal A>terminal B, PN junction works as a diode, and terminal B>GND terminal A, PN junction operates as a parasitic transistor. The parasitic element is inevitably formed because of the IC construction. The operation of the parasitic element gives rise to mutual interference between circuits and results in malfunction, and eventually, breakdown. Consequently, take utmost care not to use the IC to operate the parasitic element such as applying voltage lower than GND (P substrate) to the input terminal. Resistor NPN Transistor Structure (NPN) (PIN B) (PIN A) E C Parasitic diode GND N P+ P+ P P P+ N GND (PIN B) P+ N N N P substrate (PIN A) B N Parasitic diode GND C N B E P substrate GND GND Parasitic diode Nearby other device Parasitic diode www.rohm.com (c) 2010 ROHM Co., Ltd. All rights reserved. 13/16 2010.05 - Rev.A Technical Note BD3504FVM,BD3500FVM,BD3501FVM,BD3502FVM 10. Output capacitor (C5) Connect the output capacitor between Vo1, Vo2 terminals and GND terminal without fail in order to stabilize output voltage. The output capacitor has a role to compensate for the phase of loop gain and to reduce output voltage fluctuation when load is rapidly changed. When there is an insufficient capacity value, there is a possibility to cause oscillation, and when the equivalent serial resistance (ESR) of the capacitors is large, output voltage fluctuation is increased when load is rapidly changed. About 220 F high-performance electrolytic capacitors are recommended, but this greatly depends on the gate capacity of external MOSFET and mutual conductance (gm), temperature and load conditions. In addition, when only ceramic capacitors with low ESR are used, or various capacitors are connected in series, the total phase allowance of loop gain becomes not sufficient, and oscillation may result. Thoroughgoing confirmation at application temperature and under load range conditions is requested. 11. Input capacitor setting method (C1, C4) The input capacitor plays a part to lower output impedance of a power supply connected to input terminals (Vcc, VIN). When output impedance of this power supply increases, the input voltages (Vcc, VIN) become unstable and there is a possibility of giving rise to oscillation and degraded ripple rejection characteristics. The use of capacitors of about 10 F with low ESR, which provide less capacity value changes caused by temperature changes, is recommended, but since input capacitor greatly depends on characteristics of the power supply used for input, substrate wiring pattern, and MOSFET gate-drain capacity, thoroughgoing confirmation under the application temperature, load range, and M-MOSFET conditions is requested. 12. NRCS terminal capacitor setting method (C3) To the present IC, there mounted is a function (Non Rush Current on Start-up: NRCS) to prevent rush current from VIN to load and output capacitor via Vo at the output voltage start-up. When the EN terminal is reset from Hi or UVLO, constant current is allowed to flow from the NRCS terminal. By this current, voltage generated at the NRCS terminal becomes the reference voltage and output voltage is started. In order to stabilize the NRCS set time, it is recommended to use a capacitor (B special) with less capacity value change caused by temperature change. 13. SCP terminal capacitor setting method (C2) The present IC incorporates a timer-latch type short-circuit protection circuit in order to prevent MOSFET from being destroyed by abnormal current when output terminal is short-circuited (operates at the time of NRCS, too). When the output terminal voltage drops 30% from output setting voltage, IC judges that the output is short-circuited. In such event, constant current begins to flow. When the voltage generated in the SCP terminal reaches 1.3V (Typ) by this current, the gate terminal is brought to the Low level. In order to stabilize the SCP setting time, a capacitor (B special) with less capacity value change caused by temperature changes is recommended. When the SCP function is not used, short-circuit the SCP terminal to the GND terminal. In addition, when the output terminal is short-circuited, the MOSFET gate voltage reaches the Vcc voltage and the large current that meets MOSFET characteristics flows to the output while the timer latch type protection circuit operates. When the current capacity of VIN terminal power supply lacks, the Vin terminal voltage lowers and the UVLO circuit operates, and the latch operation may not be finished. In such event, connect a limiting resistor across drain terminal and VIN terminal of MOSFET. 14. Input terminals (VCC, VIN, EN) In the present IC, N terminal, VIN terminal, and VCC terminal have an independent construction. In addition, in order to prevent malfunction at the time of low input, the UVLO function is equipped with the VIN terminal and the VCC terminal. They begin to start output voltage when all the terminals reach threshold voltage without depending on the input order of input terminals. 15. Maximum output current (maximum load) The maximum output current capacity of the power supply which is composed by the use of the present IC depends on the external FET. Consequently, confirm the characteristics of the power required for the set to be used, choose the external FET. 16. Operating ranges If it is within the operating ranges, certain circuit functions and operations are warranted in the working ambient temperature range. With respect to characteristic values, it is unable to warrant standard values of electric characteristics but there are no sudden variations in characteristic values within these ranges. 17. Allowable loss Pd With respect to the allowable loss, the thermal derating characteristics are shown in the Exhibit, which we hope would be used as a good-rule-of-thumb. Should the IC be used in such a manner to exceed the allowable loss, reduction of current capacity due to chip temperature rise, and other degraded properties inherent to the IC would result. You are strongly urged to use the IC within the allowable loss. 18. The use in the strong electromagnetic field may sometimes cause malfunction, to which care must be taken. 19.In the event that load containing a large inductance component is connected to the output terminal, and generation of back-EMF at the start-up and when output is turned OFF is assumed, it is requested to insert a protection diode. 20. We are certain that examples of applied circuit diagrams are recommendable, but you are requested to thoroughly confirm the characteristics before using the IC. In addition, when the IC is used with the external circuit changed, decide the IC with sufficient margin provided while consideration is being given not only to static characteristics but also variations of external parts and our IC including transient characteristics. www.rohm.com (c) 2010 ROHM Co., Ltd. All rights reserved. 14/16 (Example) OUTPUT PIN 2010.05 - Rev.A Technical Note BD3504FVM,BD3500FVM,BD3501FVM,BD3502FVM Power Dissipation 500 437.5mW Power Dissipation : Pd mW) 400 Without heat sink. j-a=286/W 300 200 100 100 0 0 25 50 75 100 125 150 Temperature Atmosphere : Ta() www.rohm.com (c) 2010 ROHM Co., Ltd. All rights reserved. 15/16 2010.05 - Rev.A Technical Note BD3504FVM,BD3500FVM,BD3501FVM,BD3502FVM Ordering part number B D 3 Part No. 5 0 4 Part No. 3504 3500 3501 3502 F V M - Package FVM: MSOP8 T R Packaging and forming specification TR: Embossed tape and reel (MSOP8) MSOP8 <Tape and Reel information> 2.80.1 4.00.2 8 7 6 5 0.60.2 +6 4 -4 0.290.15 2.90.1 (MAX 3.25 include BURR) Tape Embossed carrier tape Quantity 3000pcs Direction of feed TR The direction is the 1pin of product is at the upper right when you hold ( reel on the left hand and you pull out the tape on the right hand ) 1 2 3 4 1PIN MARK 1pin +0.05 0.145 -0.03 0.475 0.080.05 0.750.05 0.9MAX S +0.05 0.22 -0.04 0.08 S Direction of feed 0.65 (Unit : mm) www.rohm.com (c) 2010 ROHM Co., Ltd. All rights reserved. Reel 16/16 Order quantity needs to be multiple of the minimum quantity. 2010.05 - Rev.A Notice Notes No copying or reproduction of this document, in part or in whole, is permitted without the consent of ROHM Co.,Ltd. The content specified herein is subject to change for improvement without notice. The content specified herein is for the purpose of introducing ROHM's products (hereinafter "Products"). If you wish to use any such Product, please be sure to refer to the specifications, which can be obtained from ROHM upon request. Examples of application circuits, circuit constants and any other information contained herein illustrate the standard usage and operations of the Products. The peripheral conditions must be taken into account when designing circuits for mass production. Great care was taken in ensuring the accuracy of the information specified in this document. However, should you incur any damage arising from any inaccuracy or misprint of such information, ROHM shall bear no responsibility for such damage. The technical information specified herein is intended only to show the typical functions of and examples of application circuits for the Products. ROHM does not grant you, explicitly or implicitly, any license to use or exercise intellectual property or other rights held by ROHM and other parties. ROHM shall bear no responsibility whatsoever for any dispute arising from the use of such technical information. The Products specified in this document are intended to be used with general-use electronic equipment or devices (such as audio visual equipment, office-automation equipment, communication devices, electronic appliances and amusement devices). The Products specified in this document are not designed to be radiation tolerant. While ROHM always makes efforts to enhance the quality and reliability of its Products, a Product may fail or malfunction for a variety of reasons. Please be sure to implement in your equipment using the Products safety measures to guard against the possibility of physical injury, fire or any other damage caused in the event of the failure of any Product, such as derating, redundancy, fire control and fail-safe designs. ROHM shall bear no responsibility whatsoever for your use of any Product outside of the prescribed scope or not in accordance with the instruction manual. The Products are not designed or manufactured to be used with any equipment, device or system which requires an extremely high level of reliability the failure or malfunction of which may result in a direct threat to human life or create a risk of human injury (such as a medical instrument, transportation equipment, aerospace machinery, nuclear-reactor controller, fuelcontroller or other safety device). ROHM shall bear no responsibility in any way for use of any of the Products for the above special purposes. If a Product is intended to be used for any such special purpose, please contact a ROHM sales representative before purchasing. If you intend to export or ship overseas any Product or technology specified herein that may be controlled under the Foreign Exchange and the Foreign Trade Law, you will be required to obtain a license or permit under the Law. Thank you for your accessing to ROHM product informations. More detail product informations and catalogs are available, please contact us. ROHM Customer Support System http://www.rohm.com/contact/ www.rohm.com (c) 2010 ROHM Co., Ltd. All rights reserved. R1010A