Datasheet 0.95V to VCC-1V, 2A 1ch Ultra Low Drop Linear Regulator BD3523HFN Key Specifications General Description The BD3523HFN is an ultra low-dropout linear chipset regulator that operates from a very low input supply. It offers ideal performance in low input voltage to low output voltage applications. The input-to-output voltage difference is minimized by using a built-in N-Channel power MOSFET with a maximum ON-Resistance of RON=150m(Max). By lowering the dropout voltage, the regulator achieves high output current of up to (IOUTMAX=2.0A), thereby, reducing conversion loss, making it comparable to switching regulator and its power transistor, choke coil, and rectifier diode constituents. BD3523HFN is a low-cost design and is available in significantly downsized package profiles. Its external resistor allows the entire range of output voltage configurations between 0.65V and 2.7V, while the NRCS (soft start) function enables a controlled output voltage ramp-up, which can be programmed to whatever power supply sequence is required. IN Input Voltage Range: 0.95V to VCC-1V VCC Input Voltage Range: 4.3V to 5.5V Output Voltage Range: 0.65V to 2.7V Output Current: 2.0A (Max) ON-Resistance: 100m(Typ) 0A (Typ) Standby Current: Operating Temperature Range: -10C to +100C Package W(Typ) x D(Typ) x H(Max) Features HSON8 2.90mm x 3.00mm x 0.60mm Internal High-Precision Reference Voltage Circuit (0.65V1%) Built-in VCC Undervoltage Lockout Circuit (VCC=3.80V) NRCS (Soft start) Function Reduces the Magnitude of In-rush Current Internal N-Channel MOSFET Built-in Short Circuit Protection (SCP) Built-in Current Limit Circuit (2.0A min) Built-in Thermal Shutdown (TSD) Circuit Tracking Function Applications Notebook computers, Desktop computers, LCD-TV, DVD, Digital appliances Typical Application Circuit and Block Diagram VCC C1 VCC 1 UVLO2 VIN UVLOLATCH VCC EN 2 VCC EN UVLO1 Reference Block CL UVLO1 VREF2 IN Current Limit IN 4 C2 VCC VREF1 NRCS NRCS0.3. VREF1 x 0.4 FB TSD SCP/TSD LATCH LATCH EN UVLO1 CL UVLO1 UVLO2 TSD SCP OUT OUT 5 6 R2 EN CFB C3 7 FB R1 NRCS 3 CNRCS NRCS EN/UVLO 8 GND Product structureSilicon monolithic integrated circuit .www.rohm.com (c) 2015 ROHM Co., Ltd. All rights reserved. TSZ2211114001 This product has no designed protection against radioactive rays 1/22 TSZ02201-0J2J0A601010-1-2 02.Nov.2015 Rev.001 BD3523HFN Pin Descriptions Pin Configuration TOP VIEW VCC GND EN FB FIN NRCS OUT IN OUT Pin No. 1 2 Pin Name VCC EN 3 NRCS 4 5 6 7 8 - IN OUT OUT FB GND FIN Pin Function Power supply pin Enable input pin In-rush current protection (NRCS) capacitor connection pin Input voltage pin Output voltage pin Output voltage pin Reference voltage feedback pin Ground pin Connected to heatsink and GND Description of Blocks 1. AMP This is an error amp that compares the reference voltage (0.65V) with FB voltage to drive the output N-Channel FET. Frequency optimization aids in attaining rapid transient response, and to support the use of ceramic capacitors on the output. AMP output voltage ranges from GND to VCC. When EN is OFF, or when UVLO is active, output goes LOW and the output of the N-Channel FET switches to OFF state. 2. EN The EN block controls the ON and OFF state of the regulator via the EN logic input pin. During OFF state, circuit voltage stabilizes at 0A, which minimizes the current consumption during standby mode. The FET is switched ON to enable discharge of the NRCS and OUT, thereby draining the excess charge and preventing the load side of an IC from malfunctioning. Since there is no electrical connection required (e.g. between the VCC pin and the ESD prevention diode), module operation is independent of the input sequence. 3. VCCUVLO To prevent malfunctions that can occur during a sudden decrease in VCC, the UVLO circuit switches the output OFF state, and (like the EN block) discharges NRCS and OUT. Once the UVLO threshold voltage (TYP3.80V) is reached, the power-ON reset is triggered and the output is restored. 4. INUVLO When IN voltage exceeds the threshold voltage, INUVLO becomes active. Once active, the status of output voltage remains ON even if IN voltage drops. (When IN voltage drops, SCP engages and output switches OFF.) Unlike EN and VCC, it is active at output startup. INUVLO can be restored either by reconnecting the EN pin or VCC pin. 5. CURRENT LIMIT During ON state, the current limit function monitors the output current of the IC against the limit value. When the output current exceeds this value, this block lowers the output current to protect the load of the IC. When it overcomes the overcurrent state, output voltage is restored to the normal value. However, when output voltage falls to or below the SCP startup voltage, the SCP function becomes active and the output switches OFF. 6. NRCS (Non Rush Current on Start-up) The soft start function enabled by connecting an external capacitor between the NRCS pin and GND. Output ramp-up can be set for any period up to the time the NRCS pin reaches VFB (0.65V). During startup, the NRCS pin serves as a 20A (TYP) constant current source to charge the external capacitor. Output start time is calculated by the formula below. TNRCS typ www.rohm.com (c) 2015 ROHM Co., Ltd. All rights reserved. TSZ2211115001 CNRCSP VFB INRCS 2/22 TSZ02201-0J2J0A601010-1-2 02.Nov.2015 Rev.001 BD3523HFN Description of Blocks -continued 7. TSD (Thermal Shut down) The shutdown (TSD) circuit is automatically latched OFF when the chip temperature exceeds the threshold temperature after the programmed time period elapses, thus protecting the IC against "thermal runaway" and heat damage. Since the TSD circuit is designed only to shut down the IC in the occurrence of extreme heat, it is important that the Tj (max) parameter should not be exceeded in the thermal design, in order to avoid potential problems with the TSD. 8. IN The IN line acts as the major current supply line, and is connected to the output N-Channel FET drain. Since there is no electrical connection (such as between the VCC pin and the ESD protection diode) required, IN operates independent of the input sequence. However, since an output N-Channel FET body diode exists between IN and OUT, a IN-OUT electric (diode) connection is present. Therefore, when output is switched ON or OFF, reverse current may flow from IN to OUT. 9. SCP When output voltage (OUT) drops, the IC assumes that OUT pin is shorted to GND and switches the output voltage OFF. After the GND short has been detected and the programmed delay time has elapsed, output is latched OFF. SCP is also effective during output startup. SCP condition can be cleared either by reconnecting the EN pin or VCC pin. Delay time is calculated by the formula below. Absolute Maximum Ratings (Ta=25C) Parameter Symbol Limit Unit VCC +6.0 (Note 1) V VIN (Note 1) V Input Voltage 1 Input Voltage 2 +6.0 IOUT Maximum Output Current 2 (Note 1) A Enable Input Voltage VEN -0.3 to +6.0 V Power Dissipation 1 Pd1 0.63 (Note 2) W Power Dissipation 2 Pd2 1.35 (Note 3) W Power Dissipation 3 Pd3 1.75 (Note 4) W Operating Temperature Range Topr -10 to +100 C Tstg -55 to +125 C Tjmax +150 C Storage Temperature Range Maximum Junction Temperature (Note 1) Should not exceed Pd. (Note 2)Derate by 5.04mW/C Ta above 25C (when mounted on a 70mm x 70mm x 1.6mm glass-epoxy board, 1-layer, copper foil area : less than 0.2%) (Note 3)Derate by 10.8mW/C Ta above 25C (when mounted on a 70mm x 70mm x 1.6mm glass-epoxy board, 1-layer, copper foil area : less than 7.0%) (Note 4)Derate by 14.0mW/C Ta above 25C (when mounted on a 70mm x 70mm x 1.6mm glass-epoxy board, 1-layer, copper foil area : less than 65.0%) Caution: Operating the IC over the absolute maximum ratings may damage the IC. The damage can either be a short circuit between pins or an open circuit between pins and the internal circuitry. Therefore, it is important to consider circuit protection measures, such as adding a fuse, in case the IC is operated over the absolute maximum ratings. Recommended Operating Conditions (Ta=25C) Parameter Symbol Rating Min Max Unit Input Voltage 1 VCC 4.3 5.5 V Input Voltage 2 VIN 0.95 VCC-1 (Note 5) V VOUT VFB 2.7 V Output Voltage Setting Range Enable Input Voltage VEN -0.3 +5.5 V NRCS Capacitance CNRCS 0.001 1 F (Note 5) VCC and IN do not have to be implemented in the order listed. www.rohm.com (c) 2015 ROHM Co., Ltd. All rights reserved. TSZ2211115001 3/22 TSZ02201-0J2J0A601010-1-2 02.Nov.2015 Rev.001 BD3523HFN Electrical Characteristics (Unless otherwise specified, Ta=25C, VCC=5V, VEN=3V, VIN=1.7V, R1=3.9k, R2=3.3k) Limit Parameter Symbol Unit Min Typ Max Bias Current Conditions ICC - 0.7 1.2 mA VCC Shutdown Mode Current IST - 0 10 A Output Current IOUT 2.0 - - A Feedback Voltage 1 VFB1 0.643 0.650 0.657 V Feedback Voltage 2 VFB2 0.637 0.650 0.663 V Line Regulation 1 Reg.l1 - 0.1 0.5 %/V VCC=4.3V to 5.5V Line Regulation 2 Reg.l2 - 0.1 0.5 %/V VIN=1.2V to 3.3V Load Regulation Reg.L - 0.5 10 mV Output ON-Resistance RON - 100 150 m Standby Discharge Current IDEN 1 - - mA IOUT=0A to 2A IOUT=2A,VIN=1.2V, Tj=-10C to +100C VEN=0V, VOUT=1V Enable Pin Input Voltage High VENHIGH 2 - - V Enable Pin Input Voltage Low VENLOW 0 - 0.8 V IEN - 7 10 A IFB -100 0 +100 nA NRCS Charge Current INRCS 12 20 28 A NRCS Standby Voltage VSTB - 0 50 mV VCCUVLO 3.5 3.8 4.1 V VCCHYS 100 160 220 mV VINUVLO 0.55 0.65 0.75 V VEN=0V Tj=-10C to +100C [ENABLE] Enable Input Bias Current VEN=3V [FEEDBACK] Feedback Pin Bias Current [NRCS] [UVLO] VCC Undervoltage Lockout Threshold Voltage VCC Undervoltage Lockout Hysteresis Voltage IN Undervoltage Lockout Threshold Voltage [SCP] SCP Start up Voltage SCP Threshold Voltage www.rohm.com (c) 2015 ROHM Co., Ltd. All rights reserved. TSZ2211115001 VOUTSCP tSCP VOUT x 0.3 VOUT x 0.4 VOUT x 0.5 45 90 4/22 200 VEN=0V VCC: Sweep-up VCC: Sweep-down IN: Sweep-up V sec TSZ02201-0J2J0A601010-1-2 02.Nov.2015 Rev.001 BD3523HFN Typical Waveforms VOUT VOUT 50mV/div 50mV/div 66mV 91mV IOUT 2A IOUT 2A 2A/div 2A/div t(10sec/div) t(10sec/div) Figure 1. Transient Response (0A to 2A) COUT=100F CFB=1000pF Figure 2. Transient Response (0A to 2A) COUT=47F CFB=1000pF VOUT VOUT 51mV 50mV/div 50mV/div 108mV IOUT IOUT 2A 2A 2A/div 2A/div t(10sec/div) t(10sec/div) Figure 3. Transient Response (0A to 2A) COUT=22F CFB=1000pF www.rohm.com (c) 2015 ROHM Co., Ltd. All rights reserved. TSZ2211115001 Figure 4. Transient Response (2A to 0A) COUT=100F CFB=1000pF 5/22 TSZ02201-0J2J0A601010-1-2 02.Nov.2015 Rev.001 BD3523HFN Typical Waveforms - continued VOUT VOUT 80mV 98mV 50mV/div 50mV/div IOUT IOUT 2A/div 2A/div 2A 2A t(10sec/div) t(10sec/div) Figure 5. Transient Response (2A to 0A) COUT=47F CFB=1000pF Figure 6. Transient Response (2A to 0A) COUT=22F CFB=1000pF VEN VEN VNRCS VNRCS VOUT VOUT t(200sec/div) t(200sec/div) Figure 7. Waveform at Output Start www.rohm.com (c) 2015 ROHM Co., Ltd. All rights reserved. TSZ2211115001 Figure 8. Waveform at Output OFF 6/22 TSZ02201-0J2J0A601010-1-2 02.Nov.2015 Rev.001 BD3523HFN Typical Waveforms - continued VCC VCC VEN VEN VIN VIN VOUT VOUT VIN to VCC to VEN VCC to VIN to VEN Figure 9. Input Sequence Figure 10. Input Sequence VCC VCC VEN VEN VIN VIN VOUT VOUT VCC to VEN to VIN VEN to VCC to VIN Figure 11. Input Sequence www.rohm.com (c) 2015 ROHM Co., Ltd. All rights reserved. TSZ2211115001 Figure 12. Input Sequence 7/22 TSZ02201-0J2J0A601010-1-2 02.Nov.2015 Rev.001 BD3523HFN Typical Waveforms - continued VCC VCC VEN VEN VIN VIN VOUT VOUT VIN to VEN to VCC VEN to VIN t o VCC Figure 13. Input Sequence www.rohm.com (c) 2015 ROHM Co., Ltd. All rights reserved. TSZ2211115001 Figure 14. Input Sequence 8/22 TSZ02201-0J2J0A601010-1-2 02.Nov.2015 Rev.001 BD3523HFN Typical Performance Curve 0.9 Icc [mA] : ICC [mA] Circuit Current Vo [V]: VOUT [V] Output Voltage 1.25 1.23 1.21 1.19 1.17 0.8 0.7 0.6 0.5 0.4 1.15 -50 -25 0 25 50 75 100 125 -50 150 -25 0 25 50 75 100 125 150 Tj [] Junction Temperature : Tj [C] Junction Temperature : Tj [C] Tj [] Figure 16. Circuit Current vs Junction Temperature Figure 15. Output Voltage vs Junction Temperature (IOUT=0mA) 3.0 2.0 2.5 1.8 IST [A] ISTB [ A] 2.0 IIN IIN [mA] [mA] 1.6 1.4 1.5 1.0 1.2 0.5 0.0 1.0 -50 -25 0 25 50 75 100 125 -50 150 0 Junction Tj [] Junction Temperature : Tj [C] Figure 17. IIN vs Junction Temperature www.rohm.com (c) 2015 ROHM Co., Ltd. All rights reserved. TSZ2211115001 -25 25 50 75 Tj [] Temperature 100 125 150 : Tj [C] Figure 18. IST vs Junction Temperature 9/22 TSZ02201-0J2J0A601010-1-2 02.Nov.2015 Rev.001 BD3523HFN Typical Performance Curve - continued 20 INRCS [ A] : INRCS [A] NRCS Charge Current 30 25 IINSTB [A] [ A] IINSTB 20 15 10 5 19 18 17 16 15 14 13 12 11 10 0 -50 -25 0 25 50 75 100 125 -50 150 0 25 50 75 100 125 150 Tj [] Junction Temperature : Tj [C] Tj [] Junction Temperature : Tj [C] Figure 20. NRCS Charge Current vs Junction Temperature Figure 19. IINSTB vs Junction Temperature 150 Output ON-Resistance : RON [m] 10 9 8 7 6 RON [m ] Enable Pin Bias : IEN [A] IENCurrent [ A] -25 5 4 3 2 1 0 -50 -25 0 25 50 75 100 125 150 110 90 70 50 -50 Tj [] Junction Temperature : Tj [C] -25 0 25 50 75 100 125 150 Tj [] Junction Temperature : Tj [C] Figure 21. Enable Pin Bias Current vs Junction Temperature www.rohm.com (c) 2015 ROHM Co., Ltd. All rights reserved. TSZ2211115001 130 Figure 22. Output ON-Resistance vs Junction Temperature (VCC=5V/VOUT=1.2V) 10/22 TSZ02201-0J2J0A601010-1-2 02.Nov.2015 Rev.001 BD3523HFN Typical Performance Curve - continued Output ON-Resistance : RON [m] RON [m ] 135 125 VOUT=2.5V 115 VOUT=1.8V 105 VOUT=1.5V VOUT=1.2V 95 VOUT=1.0V 85 75 3 4 5 6 7 8 Supply Voltage Tj [] : VCC [V] Figure 23. Output ON-Resistance vs VCC www.rohm.com (c) 2015 ROHM Co., Ltd. All rights reserved. TSZ2211115001 11/22 TSZ02201-0J2J0A601010-1-2 02.Nov.2015 Rev.001 BD3523HFN Timing Chart EN ON/OFF IN VCC EN 0.65V(typ) NRCS Startup OUT t VCC ON/OFF IN UVLO Hysteresis VCC EN 0.65V(typ) NRCS Startup OUT t www.rohm.com (c) 2015 ROHM Co., Ltd. All rights reserved. TSZ2211115001 12/22 TSZ02201-0J2J0A601010-1-2 02.Nov.2015 Rev.001 BD3523HFN Timing Chart - continued IN ON VINUVLO IN VCC EN NRCS OUT SCP OFF IN VCC EN NRCS OUT www.rohm.com (c) 2015 ROHM Co., Ltd. All rights reserved. TSZ2211115001 SCP startup voltage 13/22 SCP delay time TSZ02201-0J2J0A601010-1-2 02.Nov.2015 Rev.001 BD3523HFN Application Information 1. Evaluation Board BD3523HFN Evaluation Board Schematic GND_S VCC 1 VCC VCC GND 8 C1 SW1 GND R8 GND 2 EN C12 U1 BD3523HFN R1 FB 7 GND 3 R4 C11 C13 R2 GND OUT 6 NRCS OUT_S IN_S GND 4 IN C4 GND C7 GND C3 GND 5 OUT C5 C2 GND GND GND C6 GND C8 GND R3 R5 C9 7568 R6 4 TP1 GND U2 TP2 321 VCC R7 JPF1 GND GND U3 5 GND GND GND JPF2 2 4 3 R9 C14 BD3523HFN Evaluation Board List Component Rating Manufacturer Product Name Component Rating Manufacturer Product Name U1 - ROHM BD3523HFN C13 1000pF MURATA GRM188B11H102KD C1 1F MURATA GRM188B11A105KD R1 3.9k ROHM MCR03EZPF3901 C3 10F KYOCERA CM32X5R106M10A R2 3.3k ROHM MCR03EAPF3301 C5 22F KYOCERA CM32X5R226M10A R4 0 - Jumper C11 0.01F MURATA GRM188B11H103KD R8 0 - Jumper BD3523HFN Evaluation Board Layout (2nd layer and 3rd layer are GND line.) Silk Screen www.rohm.com (c) 2015 ROHM Co., Ltd. All rights reserved. TSZ2211115001 TOP Layer 14/22 Bottom Layer TSZ02201-0J2J0A601010-1-2 02.Nov.2015 Rev.001 BD3523HFN 2. Recommended Circuit Example GND 1 VCC VCC 6 8 GND C1 R1 2 VEN FB EN R2 3 OUT NRCS R1/R2 OUT IN 5 C2 Recommended Value 3.9k/3.3k OUT C3 4 Component C5 6 C4 VIN FB 7 R4 Programming Notes and Precautions IC output voltage can be set by internal reference voltage (VFB) and a value of the output voltage setting resistance (R1, R2). Select resistance values that will avoid the impact of the FB bias current (100nA). The recommended total resistance value is 10k. 22F To ensure output voltage stability, make sure that the output capacitors are connected between OUT pin and GND. Output capacitors play a role in loop gain phase compensation and in mitigating output fluctuation during rapid changes in load level. Insufficient capacitance may cause oscillation, while high equivalent series reisistance (ESR) will exacerbate output voltage fluctuation under rapid load change conditions. While a 22F ceramic capacitor is recomended, actual stability is highly dependent on temperature and load conditions. Also, note that connecting different types of capacitors in series may result in insufficient total phase compensation, thus causing oscillation. Please confirm operation across a variety of temperature and load conditions. 1F/10F Input capacitors reduce the output impedance of the voltage supply source connected to the input pin (VCC, IN). If the impedance of this power supply were to increase, input voltage (VCC, VIN) could become unstable, leading to oscillation or lowered ripple rejection function. While a low-ESR 1F/10F capacitor with minimal susceptibility to temperature is recommended, stability is highly dependent on the input power supply characteristics and the substrate wiring pattern. In light of this information, please confirm operation across a variety of temperature and load conditions. C4 0.01F The Non Rush Current on Startup (NRCS) function is built into the IC to prevent rush current from going through the load (IN to OUT) and affects output capacitors at power supply start-up. Constant current comes from the NRCS pin when EN is HIGH or when the UVLO function is deactivated. The temporary reference voltage is proportional to time, due to the current charge of the NRCS pin capacitor, and output voltage start-up is proportional to this reference voltage. Capacitors with low susceptibility to temperature are recommended, to ensure a stable soft-start time. C5 - This component is employed when the C3 capacitor causes, or may cause, oscillation. It provides more precise internal phase correction. R4 Several k to several 10k It is recommended that a resistance (several k to several 10k) be put in R4, in case negative voltage is applied in EN pin. C3 C1/ C2 www.rohm.com (c) 2015 ROHM Co., Ltd. All rights reserved. TSZ2211115001 15/22 TSZ02201-0J2J0A601010-1-2 02.Nov.2015 Rev.001 BD3523HFN 3. Power Dissipation In the thermal design, consider the temperature ranges wherein the IC is guaranteed to operate and apply appropriate margins. The temperature conditions that need to be considered are listed below: (1) Ambient temperature Ta can be no higher than 100C. (2) Chip junction temperature (Tj) can be no higher than 150C. Chip junction temperature can be determined as follows: Calculation based on ambient temperature (Ta) Tj Ta j a W <Reference values> j-a: HSON8 198.4C/W 1-layer substrate (copper foil area : below 0.2%) 92.4C/W 1-layer substrate (copper foil area : 7%) 71.4C/W 2-layer substrate (copper foil area : 65%) Substrate size: 70 x 70 x 1.6mm3 (substrate with thermal via) It is recommended to layout the VIA for heat radiation in the GND pattern of reverse (of IC) when there is the GND pattern in the inner layer (in using multiplayer substrate). This package is so small (size: 2.9mm x 3.0mm) that it is not available to layout the VIA in the bottom of IC. Spreading the pattern and increasing the number of VIA, as shown in the figure below, enable to achieve superior heat radiation characteristic. (This figure is an image only. It is recommended that the VIA size and number is designed suitable for the actual situation.). Most of the heat loss in BD3523HFN occurs at the output N-Channel FET. Power loss is determined by the total VIN-VOUT voltage and output current. Be sure to confirm the system input and output voltage and the output current conditions in relation to the heat dissipation characteristics of the IN and OUT in the design. Bearing in mind that heat dissipation may vary substantially depending on the substrate employed (due to the power package incorporated in the BD3523HFN) make sure to factor in conditions such as substrate size into the thermal design. Power consumption (W) = Input voltage (VIN)- Output voltage (VOUT) x IOUT(Ave) Example) Where VIN=1.7V, VOUT=1.2V, IOUT(Ave) = 2A, Power consumption W 1.7 V 1.2 V 2.0 A 1.0 W [W] 2.0 Power Dissipation [Pd] HSON8 (3) 1.75W (1) 1 layer substrate (substrate surface copper foil area: below 0.2%) j-a=198.4C/W (2) 1 layer substrate (substrate surface copper foil area:7%) j-a=92.4C/W (3) 1 layer substrate (substrate surface copper foil area:65%) j-a=71.4C/W 1.5 (2) 1.35W 1.0 (1) 0.63W 0.5 0 0 25 50 75 100 Ambient Temperature [Ta] www.rohm.com (c) 2015 ROHM Co., Ltd. All rights reserved. TSZ2211115001 125 150 [C] 16/22 TSZ02201-0J2J0A601010-1-2 02.Nov.2015 Rev.001 BD3523HFN I/O Equivalent Circuits VCC VCC EN 1k 1k NRCS 1k 1k 1k IN 400k 1k 210k 1k 90k VCC VCC FB 1k 10k OUT 50k 1k 1k www.rohm.com (c) 2015 ROHM Co., Ltd. All rights reserved. TSZ2211115001 17/22 TSZ02201-0J2J0A601010-1-2 02.Nov.2015 Rev.001 BD3523HFN Operational Notes 1. Reverse Connection of Power Supply Connecting the power supply in reverse polarity can damage the IC. Take precautions against reverse polarity when connecting the power supply, such as mounting an external diode between the power supply and the IC's power supply pins. 2. Power Supply Lines Design the PCB layout pattern to provide low impedance supply lines. Separate the ground and supply lines of the digital and analog blocks to prevent noise in the ground and supply lines of the digital block from affecting the analog block. Furthermore, connect a capacitor to ground at all power supply pins. Consider the effect of temperature and aging on the capacitance value when using electrolytic capacitors. 3. Ground Voltage Ensure that no pins are at a voltage below that of the ground pin at any time, even during transient condition. 4. Ground Wiring Pattern When using both small-signal and large-current ground traces, the two ground traces should be routed separately but connected to a single ground at the reference point of the application board to avoid fluctuations in the small-signal ground caused by large currents. Also ensure that the ground traces of external components do not cause variations on the ground voltage. The ground lines must be as short and thick as possible to reduce line impedance. 5. Thermal Consideration Should by any chance the power dissipation rating be exceeded the rise in temperature of the chip may result in deterioration of the properties of the chip. In case of exceeding this absolute maximum rating, increase the board size and copper area to prevent exceeding the Pd rating. 6. Recommended Operating Conditions These conditions represent a range within which the expected characteristics of the IC can be approximately obtained. The electrical characteristics are guaranteed under the conditions of each parameter. 7. Inrush Current When power is first supplied to the IC, it is possible that the internal logic may be unstable and inrush current may flow instantaneously due to the internal powering sequence and delays, especially if the IC has more than one power supply. Therefore, give special consideration to power coupling capacitance, power wiring, width of ground wiring, and routing of connections. 8. Operation Under Strong Electromagnetic Field Operating the IC in the presence of a strong electromagnetic field may cause the IC to malfunction. 9. Testing on Application Boards When testing the IC on an application board, connecting a capacitor directly to a low-impedance output pin may subject the IC to stress. Always discharge capacitors completely after each process or step. The IC's power supply should always be turned off completely before connecting or removing it from the test setup during the inspection process. To prevent damage from static discharge, ground the IC during assembly and use similar precautions during transport and storage. 10. Inter-pin Short and Mounting Errors Ensure that the direction and position are correct when mounting the IC on the PCB. Incorrect mounting may result in damaging the IC. Avoid nearby pins being shorted to each other especially to ground, power supply and output pin. Inter-pin shorts could be due to many reasons such as metal particles, water droplets (in very humid environment) and unintentional solder bridge deposited in between pins during assembly to name a few. 11. Unused Input Pins Input pins of an IC are often connected to the gate of a MOS transistor. The gate has extremely high impedance and extremely low capacitance. If left unconnected, the electric field from the outside can easily charge it. The small charge acquired in this way is enough to produce a significant effect on the conduction through the transistor and cause unexpected operation of the IC. So unless otherwise specified, unused input pins should be connected to the power supply or ground line. www.rohm.com (c) 2015 ROHM Co., Ltd. All rights reserved. TSZ2211115001 18/22 TSZ02201-0J2J0A601010-1-2 02.Nov.2015 Rev.001 BD3523HFN Operational Notes - continued 12. Regarding the Input Pin of the IC This monolithic IC contains P+ isolation and P substrate layers between adjacent elements in order to keep them isolated. P-N junctions are formed at the intersection of the P layers with the N layers of other elements, creating a parasitic diode or transistor. For example (refer to figure below): When GND > Pin A and GND > Pin B, the P-N junction operates as a parasitic diode. When GND > Pin B, the P-N junction operates as a parasitic transistor. Parasitic diodes inevitably occur in the structure of the IC. The operation of parasitic diodes can result in mutual interference among circuits, operational faults, or physical damage. Therefore, conditions that cause these diodes to operate, such as applying a voltage lower than the GND voltage to an input pin (and thus to the P substrate) should be avoided. Resistor Transistor (NPN) Pin A Pin B C E Pin A N P+ P N N P+ N Pin B B Parasitic Elements N P+ N P N P+ B N C E Parasitic Elements P Substrate P Substrate GND GND Parasitic Elements GND Parasitic Elements GND N Region close-by Figure 24. Example of monolithic IC structure 13. Area of Safe Operation (ASO) Operate the IC such that the output voltage, output current, and power dissipation are all within the Area of Safe Operation (ASO). 14. Thermal Shutdown Circuit(TSD) This IC has a built-in thermal shutdown circuit that prevents heat damage to the IC. Normal operation should always be within the IC's power dissipation rating. If however the rating is exceeded for a continued period, the junction temperature (Tj) will rise which will activate the TSD circuit that will turn OFF all output pins. The IC should be powered down and turned ON again to resume normal operation because the TSD circuit keeps the outputs at the OFF state even if the TJ falls below the TSD threshold. Note that the TSD circuit operates in a situation that exceeds the absolute maximum ratings and therefore, under no circumstances, should the TSD circuit be used in a set design or for any purpose other than protecting the IC from heat damage. TSD on temperature [C] (typ) BD3523HFN 175 15. Output Pin 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. (Example) OUTPUT PIN www.rohm.com (c) 2015 ROHM Co., Ltd. All rights reserved. TSZ2211115001 19/22 TSZ02201-0J2J0A601010-1-2 02.Nov.2015 Rev.001 BD3523HFN Ordering Information B D 3 5 2 Part Number 3 H F N Package HFN : HSON8 - TR Packaging and forming specification TR: Embossed tape and reel Marking Diagram HSON8 (TOP VIEW) Part Number Marking B D 3 LOT Number 5 2 3 1PIN MARK www.rohm.com (c) 2015 ROHM Co., Ltd. All rights reserved. TSZ2211115001 20/22 TSZ02201-0J2J0A601010-1-2 02.Nov.2015 Rev.001 BD3523HFN Physical Dimension, Tape and Reel Information Package Name www.rohm.com (c) 2015 ROHM Co., Ltd. All rights reserved. TSZ2211115001 HSON8 21/22 TSZ02201-0J2J0A601010-1-2 02.Nov.2015 Rev.001 BD3523HFN Revision History Date Revision 02.Nov.2015 001 Changes New Release www.rohm.com (c) 2015 ROHM Co., Ltd. All rights reserved. TSZ2211115001 22/22 TSZ02201-0J2J0A601010-1-2 02.Nov.2015 Rev.001 Datasheet Notice Precaution on using ROHM Products 1. Our Products are designed and manufactured for application in ordinary electronic equipments (such as AV equipment, OA equipment, telecommunication equipment, home electronic appliances, amusement equipment, etc.). If you (Note 1) , transport intend to use our Products in devices requiring extremely high reliability (such as medical equipment equipment, traffic equipment, aircraft/spacecraft, nuclear power controllers, fuel controllers, car equipment including car accessories, safety devices, etc.) and whose malfunction or failure may cause loss of human life, bodily injury or serious damage to property ("Specific Applications"), please consult with the ROHM sales representative in advance. Unless otherwise agreed in writing by ROHM in advance, ROHM shall not be in any way responsible or liable for any damages, expenses or losses incurred by you or third parties arising from the use of any ROHM's Products for Specific Applications. (Note1) Medical Equipment Classification of the Specific Applications JAPAN USA EU CHINA CLASS CLASSb CLASS CLASS CLASS CLASS 2. ROHM designs and manufactures its Products subject to strict quality control system. However, semiconductor products can fail or malfunction at a certain rate. Please be sure to implement, at your own responsibilities, adequate safety measures including but not limited to fail-safe design against the physical injury, damage to any property, which a failure or malfunction of our Products may cause. The following are examples of safety measures: [a] Installation of protection circuits or other protective devices to improve system safety [b] Installation of redundant circuits to reduce the impact of single or multiple circuit failure 3. Our Products are designed and manufactured for use under standard conditions and not under any special or extraordinary environments or conditions, as exemplified below. Accordingly, ROHM shall not be in any way responsible or liable for any damages, expenses or losses arising from the use of any ROHM's Products under any special or extraordinary environments or conditions. If you intend to use our Products under any special or extraordinary environments or conditions (as exemplified below), your independent verification and confirmation of product performance, reliability, etc, prior to use, must be necessary: [a] Use of our Products in any types of liquid, including water, oils, chemicals, and organic solvents [b] Use of our Products outdoors or in places where the Products are exposed to direct sunlight or dust [c] Use of our Products in places where the Products are exposed to sea wind or corrosive gases, including Cl2, H2S, NH3, SO2, and NO2 [d] Use of our Products in places where the Products are exposed to static electricity or electromagnetic waves [e] Use of our Products in proximity to heat-producing components, plastic cords, or other flammable items [f] Sealing or coating our Products with resin or other coating materials [g] Use of our Products without cleaning residue of flux (even if you use no-clean type fluxes, cleaning residue of flux is recommended); or Washing our Products by using water or water-soluble cleaning agents for cleaning residue after soldering [h] Use of the Products in places subject to dew condensation 4. The Products are not subject to radiation-proof design. 5. Please verify and confirm characteristics of the final or mounted products in using the Products. 6. In particular, if a transient load (a large amount of load applied in a short period of time, such as pulse. is applied, confirmation of performance characteristics after on-board mounting is strongly recommended. Avoid applying power exceeding normal rated power; exceeding the power rating under steady-state loading condition may negatively affect product performance and reliability. 7. De-rate Power Dissipation depending on ambient temperature. When used in sealed area, confirm that it is the use in the range that does not exceed the maximum junction 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-PGA-E (c) 2015 ROHM Co., Ltd. All rights reserved. Rev.002 Datasheet Precautions Regarding Application Examples and External Circuits 1. If change is made to the constant of an external circuit, please allow a sufficient margin considering variations of the characteristics of the Products and external components, including transient characteristics, as well as static characteristics. 2. You agree that application notes, reference designs, and associated data and information contained in this document are presented only as guidance for Products use. Therefore, in case you use such information, you are solely responsible for it and you must exercise your own independent verification and judgment in the use of such information contained in this document. ROHM shall not be in any way responsible or liable for any damages, expenses or losses incurred by you or third parties arising from the use of such information. Precaution for Electrostatic This Product is electrostatic sensitive product, which may be damaged due to electrostatic discharge. Please take proper caution in your manufacturing process and storage so that voltage exceeding the Products maximum rating will not be applied to Products. Please take special care under dry condition (e.g. Grounding of human body / equipment / solder iron, isolation from charged objects, setting of Ionizer, friction prevention and temperature / humidity control). Precaution for Storage / Transportation 1. Product performance and soldered connections may deteriorate if the Products are stored in the places where: [a] the Products are exposed to sea winds or corrosive gases, including Cl2, H2S, NH3, SO2, and NO2 [b] the temperature or humidity exceeds those recommended by ROHM [c] the Products are exposed to direct sunshine or condensation [d] the Products are exposed to high Electrostatic 2. Even under ROHM recommended storage condition, solderability of products out of recommended storage time period may be degraded. It is strongly recommended to confirm solderability before using Products of which storage time is exceeding the recommended storage time period. 3. Store / transport cartons in the correct direction, which is indicated on a carton with a symbol. Otherwise bent leads may occur due to excessive stress applied when dropping of a carton. 4. Use Products within the specified time after opening a humidity barrier bag. Baking is required before using Products of which storage time is exceeding the recommended storage time period. Precaution for Product Label QR code printed on ROHM Products label is for ROHM's internal use only. Precaution for Disposition When disposing Products please dispose them properly using an authorized industry waste company. Precaution for Foreign Exchange and Foreign Trade act Since 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. All information and data including but not limited to application example contained in this document is for reference only. ROHM does not warrant that foregoing information or data will not infringe any intellectual property rights or any other rights of any third party regarding such information or data. 2. ROHM shall not have any obligations where the claims, actions or demands arising from the combination of the Products with other articles such as components, circuits, systems or external equipment (including software). 3. No license, expressly or implied, is granted hereby under any intellectual property rights or other rights of ROHM or any third parties with respect to the Products or the information contained in this document. Provided, however, that ROHM will not assert its intellectual property rights or other rights against you or your customers to the extent necessary to manufacture or sell products containing the Products, subject to the terms and conditions herein. 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-PGA-E (c) 2015 ROHM Co., Ltd. All rights reserved. Rev.002 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 (c) 2015 ROHM Co., Ltd. All rights reserved. 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