BD81A74EFV-ME2

Datasheet 4ch White LED Driver Built-in Current Driver Buck-Boost and Boost DC/DC Converter for Automotive BD81A74EFV-M BD81A74MUV-M General Description BD81A74EFV-M / BD81A74MUV-M is a white LED driver with the capability of withstanding high input voltage (maximum 35 V). This driver has 4ch constantcurrent drivers in 1-chip, where each channel can draw up to 120 mA (Max), and it is suitable for high illumination LED drive. Furthermore, a buck-boost current mode DC/DC converter is also built to achieve stable operation during power voltage fluctuation. Light modulation (10,000:1@100 Hz dimming function) is possible by PWM input. Features ◼ ◼ ◼ ◼ ◼ ◼ ◼ ◼ AEC-Q100 Qualified*1 4ch Current Driver for LED Drive Buck-Boost Current Mode DC/DC Converter Control DC/DC Converter Oscillation Frequency by External Synchronized Signal Spread Spectrum Function LSI Protection Function (UVLO, OVP, TSD, OCP, SCP) LED Abnormality Detection Function (Open/Short) VOUT Discharge Function (Buck-Boost Structure Limitation) *1 Grade 1 Key Specifications ◼ ◼ ◼ ◼ ◼ ◼ ◼ Operating Input Voltage Range 4.5 V to 35 V Output LED Current Accuracy ±3.0 %@50 mA DC/DC Oscillation Frequency 200 kHz to 2200 kHz Operating Temperature -40 °C to +125 °C LED Maximum Output Current 120 mA/ch LED Maximum Dimming Ratio 10,000:1@100 Hz PWM Minimum Pulse Width 1.0 µs Packages VQFN28SV5050 HTSSOP-B28 VQFN28SV5050 BD81A74MUV-M W (Typ) x D (Typ) x H (Max) 5.0 mm x 5.0 mm x 1.0 mm 9.7 mm x 6.4 mm x 1.0 mm HTSSOP-B28 BD81A74EFV-M Applications ◼ ◼ ◼ ◼ ◼ Automotive CID (Center Information Display) Panel Car Navigation Cluster Panel HUD (Head Up Display) Small and Medium Type LCD Panels for Automotive Use Typical Application Circuit 〇Product structure : Silicon integrated circuit 〇This product has no designed protection against radioactive rays 〇This product is protected by U.S. Patent No.7,235,954, No.7,541,785, No.7,944,189. www.rohm.com TSZ02201-0T2T0C600300-1-2 ©2017 ROHM Co., Ltd. All rights reserved. 1/41 8.Oct.2021 Rev.007 TSZ22111 • 14 • 001 BD81A74EFV-M BD81A74MUV-M Pin Configuration VQFN28SV5050 (TOP VIEW) Pin Description Pin No. Pin Name Function 1 LEDEN1 Enable pin 1 for LED output 2 LEDEN2 Enable pin 2 for LED output 3 LED1 LED output pin 1 4 LED2 LED output pin 2 5 LED3 LED output pin 3 6 LED4 LED output pin 4 7 OVP Over voltage detection pin 8 ISET LED output current setting pin 9 PGND LED output GND pin 10 OUTL Low side FET gate pin 11 DGND DC/DC converter output GND pin 12 VDISC Output voltage discharge pin 13 SW 14 OUTH High side FET source pin High side FET gate pin 15 BOOT High side FET driver power supply pin 16 VREG Internal constant voltage 17 EN Enable pin 18 CS DC/DC converter current sense pin 19 VCC 20 SS 21 COMP Input power supply pin “Soft Start” capacitor connection Error Amp output 22 RT 23 SYNC External synchronization input pin 24 SSCG Spread spectrum setting capacitor pin 25 GND Small signal GND pin 26 PWM PWM light modulation signal input pin 27 FAIL1 “Failure” signal output pin 1 28 FAIL2 “Failure” signal output pin 2 - EXP-PAD www.rohm.com © 2017 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 Oscillation frequency setting resistor connect Back side thermal PAD (Connect to GND) 2/41 TSZ02201-0T2T0C600300-1-2 8.Oct.2021 Rev.007 BD81A74EFV-M BD81A74MUV-M Pin Configuration HTSSOP-B28 (TOP VIEW) Pin Description Pin No. Pin Name 1 VCC 2 SS 3 COMP Function Input power supply pin “Soft Start” capacitor connection Error Amp output 4 RT 5 SYNC Oscillation frequency setting resistor connect External synchronization input pin 6 SSCG Spread spectrum setting capacitor pin 7 GND Small signal GND pin 8 PWM PWM light modulation signal input pin 9 FAIL1 “Failure” signal output pin 1 10 FAIL2 “Failure” signal output pin 2 11 LEDEN1 Enable pin 1 for LED output 12 LEDEN2 Enable pin 2 for LED output 13 LED1 LED output pin 1 14 LED2 LED output pin 2 15 LED3 LED output pin 3 16 LED4 LED output pin 4 17 OVP Over voltage detection pin 18 ISET LED output current setting pin 19 PGND LED output GND pin 20 OUTL Low side FET gate pin 21 DGND DC/DC converter output GND pin 22 VDISC Output voltage discharge pin 23 SW 24 OUTH High side FET gate pin 25 BOOT High side FET driver power supply pin 26 VREG Internal constant voltage 27 EN Enable pin 28 CS DC/DC converter current sense pin - EXP-PAD www.rohm.com © 2017 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 High side FET source pin Back side thermal PAD (Connect to GND) 3/41 TSZ02201-0T2T0C600300-1-2 8.Oct.2021 Rev.007 BD81A74EFV-M BD81A74MUV-M Block Diagram www.rohm.com © 2017 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 4/41 TSZ02201-0T2T0C600300-1-2 8.Oct.2021 Rev.007 BD81A74EFV-M BD81A74MUV-M Description of Blocks If there is no description, the mentioned values are typical value. 1. Reference Voltage (VREG) VREG Block generates 5 V at EN = High, and outputs to the VREG pin. This voltage (V VREG) is used as power supply for internal circuit. It is also used to fix each input pin to High voltage outside IC. It cannot supply power to other parts than this IC. The VREG pin has UVLO function, and it starts operation at VCC ≥ 4.0 V and VVREG ≥ 3.5 V and stops when at VCC ≤ 3.5 V or VVREG ≤ 2.0 V. About the condition to release/detect VREG voltage, refer to Table 2 on section 4 4. Protection Feature. Connect a ceramic capacitor (CVREG) to the VREG pin for phase margin. CVREG range is 1.0 µF to 4.7 µF and recommended value is 2.2 µF. If the CVREG is not connected, it might occur unstable operation e.g. oscillation. 2. Current Driver Table 1. LED Control Logic If there is the constant-current driver output not to use, make the LED1 to LED4 pins ‘open’ and turn off the channel, which is not used, with the LEDEN1 and LEDEN2 pins. The truth table for these pins is shown above. If the unused constant-current driver output is set open without the process of the LEDEN1 and LEDEN2 pins, the ‘open detection’ is activated. The LEDEN1 and LEDEN2 pins are pulled down internally in the IC and it is low at ‘open’ condition. They can be connected to the VREG pin and fixed to logic High. Logic of the LEDEN1 ILED [mA] and LEDEN2 pins are not switchable during these in operation. (1) Output Current Setting (RISET) 120 110 100 90 80 70 60 50 40 30 20 40 60 80 100 120 140 160 180 200 220 240 RISET [kΩ] Figure 1. ILED vs RISET The Output Current ILED can be obtained by the following equation: 𝐼𝐿𝐸𝐷 = 5000/𝑅𝐼𝑆𝐸𝑇 [A] The operating range of the RISET value is from 41 kΩ to 250 kΩ. Additionally, the RISET value could not be changed during operation. In this IC, ISET-GND short protection is built-in to protect an LED element from excess current when the ISET pin and GND are shorted. If the RISET value is 4.7 kΩ or less, the IC detects ISET-GND short condition and LED current is turned off. www.rohm.com © 2017 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 5/41 TSZ02201-0T2T0C600300-1-2 8.Oct.2021 Rev.007 BD81A74EFV-M 2. BD81A74MUV-M Current Driver – continued During PWM dimming, the LED pin voltage (VLED) rises when PWM = Low because LED current doesn't flow, and controls VLED to 1 V when PWM = High. When PWM rise up, VLED undershoot may occur depends on LED current setting or external parts including the output capacitor. The undershoot is large especially at high temperature and large LED current. LED current may decrease instantly as Figure 2(a) shows by the undershoot. The undershoot and the settable LED current are shown in Figure 2(b). If the LED current is decreased with the undershoot, it may not see as the LED flicker. Evaluate with the actual application certainly, and check at the visual perspective. PWM LED pin control voltage VLED ILED Undershoot (ΔVdrop) (a) Timing Chart of VLED, ILED at PWM Dimming (b) Temperature(Ta) vs LED Current(ILED) Figure 2. Relation Between Undershoot of VLED and LED Current (2) PWM Dimming Control 1 ms/Div 500 ns/Div PWM (2 V/Div) PWM (2 V/Div) ILED (50 mA/Div) ILED (50 mA/Div) (a) PWM = 150 Hz, Duty = 0.02 %, ILED Waveform (b) PWM = 150 Hz, Duty = 50.0 %, ILED Waveform Figure 3. PWM Dimming Waveform The current driver ON/OFF is controlled by the PWM pin. The duty ratio of the PWM pin becomes duty ratio of ILED. If PWM dimming is not totally used (i.e. 100 %), fix the PWM pin to High. Output light intensity is the highest at 100 %. www.rohm.com © 2017 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 6/41 TSZ02201-0T2T0C600300-1-2 8.Oct.2021 Rev.007 BD81A74EFV-M BD81A74MUV-M Description of Blocks – continued 3. Buck-Boost DC/DC Converter (1) Number of LED in Series Connection This IC controls output voltage to become 1.0 V by detecting LED cathode voltage (the LED1 to LED4 pins voltage). When multiple LED outputs are operating, it controls LED pin voltage with the highest LED Vf to become 1.0 V. Thus, the output voltage of other LED pins is higher by the variations of Vf. Set up Vf variation to meet the formula below. 𝐿𝐸𝐷 𝑆𝑒𝑟𝑖𝑒𝑠 𝑁𝑢𝑚𝑏𝑒𝑟 × 𝑉𝑓 𝑉𝑎𝑟𝑖𝑎𝑡𝑖𝑜𝑛 < 𝑆ℎ𝑜𝑟𝑡 𝐷𝑒𝑡𝑒𝑐𝑡𝑖𝑜𝑛 𝑉𝑜𝑙𝑡𝑎𝑔𝑒 (𝑀𝑖𝑛)－ 𝐿𝐸𝐷 𝐶𝑜𝑛𝑡𝑟𝑜𝑙 𝑉𝑜𝑙𝑡𝑎𝑔𝑒(𝑀𝑎𝑥) (2) Over Voltage Protection (OVP) The output voltage (VOUT) should be connected to the OVP pin via resistor voltage divider. If the OVP pin voltage is 2.0 V or more, Over Voltage Protection (OVP) is active and stop the DC/DC converter switching. Determine the setting value of OVP function by the total number of the LEDs in the series and the Vf variation. When the OVP pin voltage drops less than 1.94 V after OVP operation, the OVP is released. 𝑉𝑂𝑈𝑇 ≥ {(𝑅𝑂𝑉𝑃1 + 𝑅𝑂𝑉𝑃2 ) ∕ 𝑅𝑂𝑉𝑃1 } × 2.0 where: 𝑉𝑂𝑈𝑇 is the Output voltage. 𝑅𝑂𝑉𝑃1 is the GND side OVP resistance. 𝑅𝑂𝑉𝑃2 is the Output voltage side OVP resistance. For example, OVP is active when VOUT ≥ 32 V if ROVP1 = 22 kΩ and ROVP2 = 330 kΩ. (3) Buck-Boost DC/DC Converter Oscillation Frequency (fOSC) fOSC [kHz] 1000 100 1 10 100 RRT [kΩ] Figure 4. fOSC vs RRT DC/DC oscillation frequency can be set via a resistor connected to the RT pin. This resistor determines the charge/discharge current to the internal capacitor, thereby changing the oscillation frequency. Set the resistance of RRT using the above data and the equation below. 𝑓𝑂𝑆𝐶 = (81 × 105 ⁄𝑅𝑅𝑇 ) [kHz] 81 x 105 is the constant value determined in the internal circuit. Take note that operation could not be guaranteed in the case of settings other than the recommended range. www.rohm.com © 2017 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 7/41 TSZ02201-0T2T0C600300-1-2 8.Oct.2021 Rev.007 BD81A74EFV-M BD81A74MUV-M 3. Buck-Boost DC/DC Converter - continued (4) Spread Spectrum Function Operation in Spread Spectrum Clock Generation (SSCG) is possible by connecting capacitor to the SSCG pin. The SSCG pin has a comparator and constant current circuit to assume 0.6 V/0.48 V reference voltage, and changes into a triangular waveform. The average of noise can be reduced by changing the switching frequency by a frequency (fSSCG) decided in the SSCG pin capacity CSSCG. The band of the switching frequency becomes 100 % to 80 % of switching frequency when SSCG is not used. Figure 5. SSCG Noise Reduction Image Figure 6. SSCG System Diagram fSSCG can be calculated by the following equation. 𝑓𝑆𝑆𝐶𝐺 = 3 4×𝐶𝑆𝑆𝐶𝐺 ×𝑅𝑅𝑇 [Hz] Set it to satisfy the equation of 0.4 kHz ≤ f SSCG ≤ 30 kHz. Furthermore, quantity of noise reduction S [dB] in SSCG can be roughly estimated by the equation below. 𝑆 = −10 × 𝑙𝑜𝑔 (𝑓 𝑓𝑆𝑆𝐶𝐺 𝑂𝑆𝐶 ) [dB] ×0.2 Short the SSCG pin and the GND pin when SSCG function is not used. (5) External Synchronization Oscillation Frequency By clock signal input to the SYNC pin, the internal oscillation frequency can be synchronized externally. Do not switch from external to internal oscillation if the DC/DC switching is active. The clock input to the SYNC pin is valid only in rising edge. Input the external input frequency within ±20 % of internal oscillatory frequency set by the RT pin resistance. (6) Soft Start Function (SS) The soft-start (SS) function can start the output voltage slowly while controlling the current during the start by connecting the capacitance (CSS) to the SS pin. In this way, output voltage overshoot and inrush current can be prevented. When SS function is not used, set the SS pin open. Refer to Setting of the Soft Start Time for the calculation of SS time. www.rohm.com © 2017 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 8/41 TSZ02201-0T2T0C600300-1-2 8.Oct.2021 Rev.007 BD81A74EFV-M BD81A74MUV-M 3. Buck-Boost DC/DC Converter - continued (7) Maximum Duty When DC/DC switching reaches Maximum Duty, expected VOUT voltage could be not output, and LED lightsout might occur by the reduction of LED output current and detection of ground short protection. Set input condition and load condition such that it does not reach Maximum Duty. (8) DC/DC Switching Control at Over Voltage Output (LSDET) When the lowest voltage in LED1 to LED4 pins (DC/DC feedback voltage) is more than 1.24 V, LSDET function works and turns off the switching of the DC/DC converter and maintains the COMP voltage (switching Duty). This function reduces the VOUT voltage quickly and intended to output stable switching Duty when VOUT is higher than the aim voltage. For example, LSDET works at the time of the LED4 OPEN detection. The timing chart example is described below. (9) PWM Pulse and DC/DC Switching After the fall of the PWM pulse, DC/DC switching is output 12 times and after that, turn off the DC/DC switching during PWM = Low. When PWM becomes High again, the DC/DC switching is on. Because of this, when PWM pulse width is short, it can maintain the output voltage and output the stable LED current. PWM +12 pulses OUTL VOUT ILED www.rohm.com © 2017 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 VOUT keep Stable LED current output 9/41 TSZ02201-0T2T0C600300-1-2 8.Oct.2021 Rev.007 BD81A74EFV-M BD81A74MUV-M Description of Blocks – continued 4. Protection Feature Table 2. Detect Condition of Each Protection Feature and Operation during Detection Function Detect Condition [Detection] [Release/Cancellation] VCC ≥ 4.0 V and Operation During Detection UVLO VCC ≤ 3.5 V or VVREG ≤ 2.0 V TSD Ta ≥ 175 °C Ta ≤ 150 °C All blocks shut down except VREG OVP VOVP ≥ 2.0 V VOVP ≤ 1.94 V DC/DC switching OFF OCP VCS ≤ VCC-0.2 V VCS > VCC-0.2 V DC/DC switching OFF EN Reset or UVLO Reset After SCP delay time, all blocks latch OFF except VREG EN Reset or UVLO Reset Only detected channel LED current latches OFF SCP LED Open Protection VOVP ≤ 0.57 V or Any of VLED1 to VLED4 is 0.3 V or less (100 ms delay @300 kHz) Any of VLED1 to VLED4 is 0.3 V or less and VOVP ≥ 2.0 V VVREG ≥ 3.5 V All blocks shut down except VREG LED Any of VLED1 to VLED4 is EN Reset After LED Short delay time, Short 4.5 V and more or only detected channel Protection (100 ms delay @300 kHz) UVLO Reset LED current latches OFF Protection Flag Output Block Diagram FAIL1 becomes low when OVP or OCP protection is detected, whereas FAIL2 becomes low when SCP, LED open or LED short is detected. If the FAIL1, FAIL2 pin is not used as a flag output, set the FAIL1, FAIL2 pin open or connect it to GND. The output from the FAIL1 and FAIL2 pins are reset and return to High by starting up of EN or release of UVLO. Also, those output is unstable when EN = Low and detecting UVLO. If the FAIL pin is used as a flag output, it is recommended to pull-up the FAIL1, FAIL2 pins to the VREG pin. The recommended value of pull-up resistance is 100 kΩ. www.rohm.com © 2017 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 10/41 TSZ02201-0T2T0C600300-1-2 8.Oct.2021 Rev.007 BD81A74EFV-M 4. BD81A74MUV-M Protection Feature - continued (1) Under-Voltage Lock Out (UVLO) The UVLO shuts down DC/DC converter and Current Driver when VCC ≤ 3.5 V or VVREG ≤ 2.0 V. And UVLO is released by VCC ≥ 4.0 V and VVREG ≥ 3.5 V. (2) Thermal Shutdown (TSD) The TSD shuts down DC/DC converter and Current Driver when the Tj 175 °C or more, and releases when the Tj becomes 150 °C or less. (3) Over Voltage Protection (OVP) The output voltage of DC/DC converter is detected from the OVP pin voltage, and the over voltage protection is activate if the OVP pin voltage becomes ≥ 2.0 V. When OVP is activated, the switching operation of the DC/DC converter turns off. And the OVP pin voltage becomes ≤ 1.94 V, OVP is released and the switching operation of the DC/DC converter turns on. (4) Over Current Protection (OCP) The OCP detects the coil current by monitoring the voltage of the high side resistor, and activates when VCS ≤ VCC-0.2 V. When the OCP is activated, the switching operation of the DC/DC converter turns off. And VCS > VCC-0.2 V, OCP is released and the switching operation of the DC/DC converter turns on. (5) Short Circuit Protection (SCP) The SCP can be operated when the SS pin voltage reaches 3.3 V while start-up. When any of the LED1 to LED4 pins voltage becomes 0.3 V or less or VOVP ≤ 0.57 V, the built-in counter operation starts. The clock frequency of counter is the oscillation frequency (fOSC), which is determined by RRT. After it counts 32770, the DC/DC converter and the current driver are latched off. When fosc = 300 kHz, the count time is 100 ms and SCP operates after this count time. If all of the LED pin voltage becomes more than 0.3 V or V OVP ≥ 1.0 V before 32770 count, the counter resets and SCP is not detected. (6) LED Open Protection When any of the LED pins voltage is 0.3 V or less and VOVP 2.0 V or more, LED open is detected and latches off the open LED channel only. (7) LED Short Protection If any of VLED1 to VLED4 is 4.5 V or more, the built-in counter operation starts. The clock frequency of counter is the oscillation frequency (fOSC), which is determined by RRT. After it counts 32770, latches off the short LED channel only. When fosc = 300 kHz, the count time is 100 ms and SCP operates after this count time. During PWM dimming, the LED Short Protection is carried out only when PWM = High. If the condition of LED Short is reset while working the counter, the counter resets and LED Short is not detected. (8) PWM Low Interval Detect The low interval of PWM input is counted by built-in counter during EN = High. The clock frequency of counter is the oscillation frequency (fOSC), which is determined by RRT. It stops the operation of circuits except VREG at 32768 counts. When fOSC = 300 kHz, the count time is 100 ms and the Low interval of PWM is detected after this count time. www.rohm.com © 2017 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 11/41 TSZ02201-0T2T0C600300-1-2 8.Oct.2021 Rev.007 BD81A74EFV-M 4. BD81A74MUV-M Protection Feature - continued (9) Output Voltage Discharge Circuit (VOUT Discharge Function) If start-up with a charge remaining at VOUT, LED might occur flicker. To prevent this, it is necessary to discharge of VOUT when starting-up. If use only resistance for setting OVP to discharge, it takes a lot time for discharging VOUT. Therefore, this product has functionality of circuit for VOUT discharge. VOUT discharge function is available at Buck-Boost application and Buck application. For this case, be sure to connect VOUT and the VDISC pin. It discharges the residual electric charge of VOUT when DC/DC circuit is OFF; changing EN High to Low or operating protect function. The discharge time (t DISC) is expressed in the following equations. 𝑡𝐷𝐼𝑆𝐶 = 3×𝑉𝑂𝑈𝑇×𝐶𝑂𝑈𝑇 [s] 4×𝐼𝐷𝐼𝑆𝐶 where: 𝑡𝐷𝐼𝑆𝐶 is the DC/DC converter output discharge time. 𝐶𝑂𝑈𝑇 is the VOUT capacity. 𝑉𝑂𝑈𝑇 is the DC/DC converter output voltage. 𝐼𝐷𝐼𝑆𝐶 is the discharge current. From the graph below, find the IDISC value in 25 % VOUT voltage, and substitute it in the above equation. For example, substitute IDISC value in VOUT = 5 V (approximately 76 mA) in the above equation when using in VOUT = 20 V, and calculate the discharge time. In order to suppress the flickering of the LED, the time of restarting EN = Low should be secured t DISC or more long. Always check with actual machine because the tDISC found here is a reference level. 0.12 0.10 IDISC [A] 0.08 0.06 0.04 0.02 0.00 0 5 10 15 20 25 30 35 40 VOUT [V] Figure 7. IDISC vs VOUT www.rohm.com © 2017 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 12/41 TSZ02201-0T2T0C600300-1-2 8.Oct.2021 Rev.007 BD81A74EFV-M BD81A74MUV-M Absolute Maximum Ratings (Ta = 25 °C) Parameter Symbol Rating Unit VCC 40 V VBOOT, VOUTH 45 V SW, CS Pin Voltage VSW, VCS 40 V BOOT-SW Pin Voltage VBOOT-SW 7 V 40 V -0.3 to +7 V -0.3 to +7 < VCC V -0.3 to +7 < VVREG V Tjmax 150 °C Storage Temperature Range Tstg -55 to +150 °C LED Maximum Output Current ILED 120*1 mA Power Supply Voltage BOOT, OUTH Pin Voltage LED1 to LED4, VDISC Pin Voltage VLEDn PWM, SYNC, EN Pin Voltage (n = 1 to 4), VVDISC VPWM, VSYNC, VEN VREG, OVP, FAIL1, FAIL2, VVREG, VOVP, VFAIL1, VFAIL2, SS, RT, SSCG Pin Voltage VSS, VRT, VSSCG LEDEN1, LEDEN2, ISET, VLEDEN1, VLEDEN2, VISET COMP, OUTL Pin Voltage VCOMP, VOUTL Maximum Junction Temperature Caution 1: 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. Caution 2: Should by any chance the maximum junction temperature 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, design a PCB board with thermal resistance taken into consideration by increasing board size and copper area so as not to exceed the maximum junction temperature rating. *1 Current level per channel. Set the LED current that does not over Junction Temperature Range (Tj) maximum. Thermal Resistance*1 Parameter Symbol Thermal Resistance (Typ) 1s*3 2s2p*4 Unit VQFN28SV5050 Junction to Ambient θJA 128.50 31.50 °C/W Junction to Top Characterization Parameter*2 ΨJT 12 9 °C/W Junction to Ambient θJA 107.00 25.10 °C/W Junction to Top Characterization Parameter*2 ΨJT 6 3 °C/W HTSSOP-B28 Layer Number of Measurement Board Single Material Board Size FR-4 114.3 mm x 76.2 mm x 1.57 mmt Top Copper Pattern Thickness Footprints and Traces 70 μm Layer Number of Measurement Board 4 Layers Material Board Size FR-4 114.3 mm x 76.2 mm x 1.6 mmt Top 2 Internal Layers Thermal Via*5 Pitch Diameter 1.20 mm Φ0.30 mm Bottom Copper Pattern Thickness Copper Pattern Thickness Copper Pattern Thickness Footprints and Traces 70 μm 74.2 mm x 74.2 mm 35 μm 74.2 mm x 74.2 mm 70 μm *1 Based on JESD51-2A(Still-Air) *2 The thermal characterization parameter to report the difference between junction temperature and the temperature at the top center of the outside surface of the component package. *3 Using a PCB board based on JESD51-3. *4 Using a PCB board based on JESD51-5, 7. *5 This thermal via connects with the copper pattern of all layers. www.rohm.com © 2017 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 13/41 TSZ02201-0T2T0C600300-1-2 8.Oct.2021 Rev.007 BD81A74EFV-M BD81A74MUV-M Recommended Operating Conditions Parameter Power Supply Voltage *1 Symbol Min Typ Max Unit VCC 4.5 12 35 V Operating Temperature Topr -40 +25 +125 °C DC/DC Oscillation Frequency fOSC 200 300 2200 kHz fSYNC Higher of 200 or fOSC x 0.8 300 Lower of 2200 or fOSC x 1.2 kHz DSYNC 40 50 60 % Max Unit External Synchronized Frequency *2 *3 External Synchronized Pulse Duty *1 This indicates the voltage near the VCC pin. Be careful of voltage drop by the impedance of power line. *2 When external synchronization frequency is not used, connect the SYNC pin to open or GND. *3 When external synchronization frequency is used, do not change to internal oscillation frequency along the way. Operating Conditions (External Constant Range) Parameter Symbol Min VREG Capacity CVREG 1.0 2.2 4.7 μF LED Current Setting Resistance Oscillation Frequency Setting Resistance Soft Start Capacity Setting RISET 41 100 250 kΩ RRT 3.6 27 41 kΩ CSS 0.047 0.1 0.47 μF Spread Spectrum Setting Capacity CSSCG 4.7 10 47 nF www.rohm.com © 2017 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 14/41 Typ TSZ02201-0T2T0C600300-1-2 8.Oct.2021 Rev.007 BD81A74EFV-M BD81A74MUV-M Electrical Characteristics(Unless otherwise specified, VCC = 12 V, Ta = -40 °C to +125 °C) Parameter Symbol Min Typ Max Unit Conditions EN = High, SYNC = High, RT = OPEN, PWM = Low, ISET = OPEN, CIN = 10 μF EN = Low, VDISC = OPEN Circuit Current ICC - - 10 mA Standby Current IST - - 10 μA VVREG 4.5 5.0 5.5 V IVREG = -5 mA, CVREG = 2.2 μF RONHH 1.5 3.5 7.0 Ω IOUTH = -10 mA 0.8 2.5 5.5 Ω IOUTH = 10 mA [VREG] Reference Voltage [OUTH] OUTH High Side ON-Resistor OUTH Low Side ON-Resistor RONHL OCP Detection Voltage VOLIMIT この行は削除してください tOLIMIT - 30 - ns VCS = VCC-0.5V OUTL High Side ON-Resistor RONLH 1.5 3.5 10.0 Ω IOUTL = -10 mA OUTL Low Side ON-Resistor RONLL 0.8 2.5 5.5 Ω IOUTL = 10 mA RON_SW 4.0 10.0 25.0 Ω ISW = 10 mA LED Control Voltage VLED 0.9 1.0 1.1 V COMP Sink Current ICOMPSINK 35 80 145 μA ICOMPSOUCE -145 -80 -35 μA VCC-0.22 VCC-0.20 VCC-0.18 V [OUTL] [SW] SW ON-Resistor [ERRAMP] COMP Source Current VLEDn = 2 V (n = 1 to 4), VCOMP = 1 V VLEDn = 0.5 V (n = 1 to 4), VCOMP = 1 V [Oscillator] Oscillation Frequency 1 fOSC1 285 300 315 kHz RRT = 27 kΩ Oscillation Frequency 2 fOSC2 1800 2000 2200 kHz RRT = 3.9 kΩ [OVP] OVP Detection Voltage VOVP1 1.9 2.0 2.1 V VOVP: Sweep up OVP Hysteresis Width VOVPHYS1 0.02 0.06 0.10 V VOVP: Sweep down www.rohm.com © 2017 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 15/41 TSZ02201-0T2T0C600300-1-2 8.Oct.2021 Rev.007 BD81A74EFV-M BD81A74MUV-M Electrical Characteristics - continued(Unless otherwise specified, VCC = 12 V, Ta = -40 °C to +125 °C) Parameter Symbol Min Typ Max Unit Conditions UVLO Detection Voltage VUVLO 3.2 3.5 3.8 V VCC: Sweep down UVLO Hysteresis Width VUHYS 0.25 0.50 0.75 V VCC: Sweep up, VVREG > 3.5 V -3 - +3 % -5 - +5 % -3 - +3 % -5 - +5 % [UVLO] [LED Output] LED Current Relative Dispersion LED Current Absolute Dispersion ILED1 ILED2 ILED = 50 mA, Ta = 25 °C ΔILED1 = (ILEDn/ILEDn_AVG-1)x 100 (n = 1 to 4) ILED = 50 mA, Ta = -40 °C to +125 °C ΔILED1 = (ILEDn/ILEDn_AVG-1)x 100 (n = 1 to 4) ILED = 50 mA, Ta = 25 °C ΔILED2 = (ILEDn/50mA-1) x 100 (n = 1 to 4) ILED = 50 mA, Ta = -40 °C to +125 °C ΔILED2 = (ILEDn/50mA-1) x 100 (n = 1 to 4) ISET Voltage VISET 0.9 1.0 1.1 V RISET = 100 kΩ PWM Minimum Pulse Width tMIN 1 - - μs fPWM = 100 Hz to 20 kHz, ILED = 20 mA to 100 mA PWM Frequency fPWM 0.1 - 20 kHz LED Open Detection Voltage VOPEN 0.2 0.3 0.4 V VLEDn :(n = 1 to 4) Sweep down LED Short Detection Voltage VSHORT 4.2 4.5 4.8 V VLEDn :(n = 1 to 4) Sweep up LED Short Detection Latch OFF Delay Time tSHORT 70 100 130 ms RRT = 27 kΩ SCP Latch OFF Delay Time tSCP 70 100 130 ms RRT = 27 kΩ PWM Latch OFF Delay Time tPWM 70 100 130 ms RRT = 27 kΩ ISET-GND Short Protection Impedance ISETPROT - - 4.7 kΩ VLSDET - 1.24 - V Input High Voltage VINH 2.1 - VVREG V EN, SYNC, PWM, LEDEN1, LEDEN2 Input Low Voltage VINL GND - 0.8 V EN, SYNC, PWM, LEDEN1, LEDEN2 IIN 15 50 100 μA VOL - 0.1 0.2 V [Protection Circuit] LSDET Detection Voltage [Logic Input Voltage] Input Current VIN = 5 V (EN, SYNC, PWM, LEDEN1, LEDEN2) [FAIL Output (Open Drain)] FAIL Low Voltage www.rohm.com © 2017 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 16/41 IFAIL = 0.1 mA TSZ02201-0T2T0C600300-1-2 8.Oct.2021 Rev.007 BD81A74EFV-M BD81A74MUV-M Typical Performance Curves (Reference Data. Unless otherwise specified, Ta = -40 °C to +125 °C) Figure 8. Circuit Current vs Power Supply Voltage (VCC = 4.5 V to 35 V, VEN = 3.3 V, VPWM = 0 V) Figure 9. Reference Voltage vs Temperature (VCC = 12 V, VEN = 3.3 V, VPWM = 0 V) Figure 10. Oscillation Frequency 1 vs Temperature (@300 kHz, VCC = 12 V, VEN = 3.3 V, RRT = 27 kΩ) Figure 11. Oscillation Frequency 2 vs Temperature (@2000 kHz, VCC = 12 V, VEN = 3.3 V, RRT = 3.6 kΩ) www.rohm.com © 2017 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 17/41 TSZ02201-0T2T0C600300-1-2 8.Oct.2021 Rev.007 BD81A74EFV-M BD81A74MUV-M Typical Performance Curves - continued (Reference Data. Unless otherwise specified, Ta = -40 °C to +125 °C) Figure 12. LED Current vs LED Voltage (Ta = 25°C, VCC = 12 V, VEN = 3.3 V, VLEDn = sweep (n = 1 to 4)) Figure 13. LED Current vs Temperature (VCC = 12 V, VEN = 3.3 V, VLEDn = 2 V (n = 1 to 4), VPWM = VVREG) Figure 14. Efficiency vs LED Current(n = 1 to 4) (Buck-Boost Application) (Ta = 25 °C, VCC = 12 V,VEN = 3.3 V, VPWM = VVREG, 4 LED loads per channel, all channels have loads) Figure 15. Efficiency vs LED Current(n = 1 to 4) (Boost Application) (Ta = 25 °C, VCC = 12 V,VEN = 3.3 V, VPWM = VVREG, 8 LED loads per channel, all channels have loads) www.rohm.com © 2017 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 18/41 TSZ02201-0T2T0C600300-1-2 8.Oct.2021 Rev.007 BD81A74EFV-M BD81A74MUV-M Timing Chart (Start-up and Protection) *1 EN is input after input VCC in the timing chart above, but there is no problem to input EN, PWM, and SYNC before input VCC. EN is judged as *2 The count time of 32770 clk x 1/fOSC. In case of fosc=300 kHz, the count time is 100 ms(typ). Low at VEN is 0.8 V or less and as High at VEN is 2.1 V or more. Do not use this IC in the condition of VEN is between 0.8 V and 2.1 V. *3 The above timing chart is when the FAIL1 and FAIL2 pins are pulled up to the VREG pin. ① When VOVP is less than 1.0 V, regardless of PWM input, the DC/DC switching operation is active (Pre-Boost function). And if VOVP reaches 1.0 V, the Pre-Boost is finished. Only when PWM is activated, switches to the Normal mode which operates the DC/DC switching. ② When VLED2 is 0.3 V or less and VOVP is 2.0 V or more, LED Open Protect is active and LED2 is turned OFF. Then FAIL2 becomes Low. ③ If the condition of VLED3 is 4.5 V or more and passes 100 ms (@fOSC = 300 kHz), LED3 is turned OFF. Then FAIL2 becomes Low. ④ When VLED4 is shorted to GND, increase the VOUT voltage. Then VOVP rises 2.0 V or more and detect OVP. FAIL1 becomes Low. If OVP occurs, DC/DC switching is OFF and decrease the VOUT voltage, then OVP repeats ON/OFF. And DC/DC switching and LED current of each channel is turned OFF after 100 ms by detecting ground short protection. (In case of f OSC = 300 kHz). www.rohm.com © 2017 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 19/41 TSZ02201-0T2T0C600300-1-2 8.Oct.2021 Rev.007 BD81A74EFV-M BD81A74MUV-M Timing Chart (Start-up and EN Restart) *1 The Low section during EN restart requires 2.0 ms or more. Restart after VOUT voltage is discharged. VOUT discharge function or external discharge switch is recommended. If EN is restarted with remaining VOUT voltage, LED flickering might occur. www.rohm.com © 2017 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 20/41 TSZ02201-0T2T0C600300-1-2 8.Oct.2021 Rev.007 BD81A74EFV-M BD81A74MUV-M Application Examples When using as Boost DC/DC converter Figure 16. Boost application Circuit If the VOUT pin or the LED pin is shorted in this case, the overcurrent from VIN cannot be prevented. To prevent overcurrent, carry out measure such as inserting fuse of which value is OCP setting value or more and is part’s rating current or less in between VCC and RCS. When using as Buck DC/DC Converter Figure 17. Buck Application Circuit www.rohm.com © 2017 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 21/41 TSZ02201-0T2T0C600300-1-2 8.Oct.2021 Rev.007 BD81A74EFV-M BD81A74MUV-M PCB Application Circuit Diagram Figure 18. PCB Application Circuit Arrange RRT resistor near the RT pin and do not attach capacitor. Arrange RISET resistor near the ISET pin and do not attach capacitor. Attach the decoupling capacitor of CIN and CVREG to IC pin as close as possible. Keep the impedance low because large current might flow into DGND and PGND. Be careful not to occur noise in the ISET, RT, and COMP pins. Since PWM, OUTH, OUTL, SW, SYNC and LED1 to LED4 have switching, avoid affecting the surrounding patterns. The SW, OUTH, BOOT pin to each components, keep shortest wiring and minimum impedance. There is thermal PAD at the back of package. Solder the board GND for thermal PAD. Set the gate resistor of FET (M1) to 0 Ω. If resistor is connected, M1 OFF timing is delayed in M1 parasitic capacity and gate resistor, and the penetrating current flows to the internal transistor of M1 and SW. The penetrating current might worsen the efficiency or detect OCP. ・ To reduce noise, consider the board layout in the shortest wiring and minimum impedance for Boost loop (D2 →CVOUT→DGND→M2→D2) and Buck loop (VCC→RCS→M1→D1→DGND→GND→CIN→VCC). ・ The ringing of Low-side FET can be suppressed by RG, but there is a concern that efficiency might worsen when RG increases. When using RG, decide the resistance value after full evaluation. ・ When PWM min pulse width satisfies the following formula, please do not connect a capacitor to LED1 to LED4 pins. It might misdetect LED short protection. When the connection of the capacitor is necessary for noise measures, please refer to us. ・ ・ ・ ・ ・ ・ ・ ・ ・ 𝑡𝑀𝐼𝑁 ≤ 10 𝑓𝑂𝑆𝐶 𝑡𝑀𝐼𝑁 ：PWM min pulse width 𝑓𝑂𝑆𝐶 ：DCDC frequency target ・ Wire both ends of RCS1 and RCS2 (Red line of below figure) most shortly. If a wiring is long, it may lead to false detection of OCP by an inductance. VCC RCS2 CCS RCS2 RCS3 CS Figure 19. The Case of RCS Parallel www.rohm.com © 2017 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 22/41 RCS3 RCS1 CS RCS1 CCS VCC Figure 20. The case of RCS Series TSZ02201-0T2T0C600300-1-2 8.Oct.2021 Rev.007 BD81A74EFV-M BD81A74MUV-M PCB Board External Components List (Buck-Boost Application) * The above components are modified according to operating conditions and load to be used. www.rohm.com © 2017 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 23/41 TSZ02201-0T2T0C600300-1-2 8.Oct.2021 Rev.007 BD81A74EFV-M BD81A74MUV-M Selection of Components Externally Connected Select the external components following the steps below. www.rohm.com © 2017 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 24/41 TSZ02201-0T2T0C600300-1-2 8.Oct.2021 Rev.007 BD81A74EFV-M BD81A74MUV-M Selection of Components Externally Connected - continued 1. Derivation of Maximum Input Leak Current IL_MAX VIN Internal IC IL RCS CS OUTH M1 L SW D2 D1 VOUT COUT M2 OUTL Output Application Circuit Diagram (Buck-Boost Application) (1) Maximum Output Voltage (VOUT_MAX) Computation Consider the Vf variation and number of LED connection in series for VOUT_MAX derivation 𝑉𝑂𝑈𝑇_𝑀𝐴𝑋 = (𝑉𝑓 + ∆𝑉𝑓) × 𝑁 + 1.1 where: 𝑉𝑂𝑈𝑇_𝑀𝐴𝑋 is the maximum output voltage. 𝑉𝑓 is the LED Vf voltage. ∆𝑉𝑓 is the LED Vf voltage variation. 𝑁 is the LED series number. (2) Maximum Output Current IOUT_MAX Computation 𝐼𝑂𝑈𝑇_𝑀𝐴𝑋 = 𝐼𝐿𝐸𝐷 × 1.05 × 𝑀 where: 𝐼𝑂𝑈𝑇_𝑀𝐴𝑋 is the maximum output current. 𝐼𝐿𝐸𝐷 is the output current per channel. 𝑀 is the LED parallel number. www.rohm.com © 2017 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 25/41 TSZ02201-0T2T0C600300-1-2 8.Oct.2021 Rev.007 BD81A74EFV-M BD81A74MUV-M 1. Derivation of Maximum Input Leak Current IL_MAX - continued (3) Maximum Input Peak Current IL_MAX Computation 1 𝐼𝐿_𝑀𝐴𝑋 = 𝐼𝐿_𝐴𝑉𝐺 + ∆𝐼𝐿 2 where: 𝐼𝐿_𝑀𝐴𝑋 is the maximum input current. 𝐼𝐿_𝐴𝑉𝐺 is the maximum input average current. ∆𝐼𝐿 is the coil current amplification. (In case of Boost Application) 𝐼𝐿_𝐴𝑉𝐺 = 𝑉𝑂𝑈𝑇_𝑀𝐴𝑋 × ∆𝐼𝐿 = 𝐼𝑂𝑈𝑇_𝑀𝐴𝑋 𝜂 × 𝑉𝐶𝐶 𝑉𝐶𝐶 1 𝑉𝑂𝑈𝑇_𝑀𝐴𝑋 − 𝑉𝐶𝐶 × × 𝐿 𝑓𝑂𝑆𝐶 𝑉𝑂𝑈𝑇_𝑀𝐴𝑋 (In case of Buck-Boost application) 𝐼𝐿_𝐴𝑉𝐺 = (𝑉𝐶𝐶 + 𝑉𝑂𝑈𝑇_𝑀𝐴𝑋 ) × ∆𝐼𝐿 = 𝐼𝑂𝑈𝑇_𝑀𝐴𝑋 𝜂 × 𝑉𝐶𝐶 𝑉𝐶𝐶 1 𝑉𝑂𝑈𝑇_𝑀𝐴𝑋 × × 𝐿 𝑓𝑂𝑆𝐶 𝑉𝐶𝐶 + 𝑉𝑂𝑈𝑇_𝑀𝐴𝑋 (In case of Buck application) 𝐼𝐿_𝐴𝑉𝐺 = 𝐼𝑂𝑈𝑇_𝑀𝐴𝑋 ∕ 𝜂 ∆𝐼𝐿 = 𝑉𝑂𝑈𝑇 1 𝑉𝐶𝐶 − 𝑉𝑂𝑈𝑇_𝑀𝐴𝑋 × × 𝐿 𝑓𝑂𝑆𝐶 𝑉𝐶𝐶 where: 𝑉𝐶𝐶 is the supply voltage. 𝜂 is the efficiency. 𝑓𝑂𝑆𝐶 is the DC/DC oscillation frequency. 𝐿 is the coil value. • The worst case for VCC is minimum, so the minimum value should be applied in the equation. • BD81A74EFV-M / BD81A74MUV-M adopts the current mode DC/DC converter control and is appropriately designed for coil value. The abovementioned value is recommended according to efficiency and stability. If choose the L values outside this recommended range, it not to be guaranteed the stable continuous operation. For example, it may cause irregular switching waveform. • η (efficiency) is around 80 %. www.rohm.com © 2017 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 26/41 TSZ02201-0T2T0C600300-1-2 8.Oct.2021 Rev.007 BD81A74EFV-M BD81A74MUV-M Selection of Components Externally Connected - continued 2. Setting of Over Current Protection Value (IOCP) 𝐼𝑂𝐶𝑃 = 𝑉𝑂𝐶𝑃_𝑀𝐼𝑁 𝑅𝐶𝑆 > 𝐼𝐿_𝑀𝐴𝑋 [A] where: 𝐼𝑂𝐶𝑃_𝑀𝐼𝑁 is the overcurrent protection detect voltage. 𝑉𝑂𝐶𝑃_𝑀𝐼𝑁 is the overcurrent protection detect voltage (0.18 V). 𝑅𝐶𝑆 is the current detect resistance. 𝐼𝐿_𝑀𝐴𝑋 is the maximum input peak current. RCS should be selected by the above equation. 3. Selection of Inductor In order to achieve stable operation of the current mode DC/DC converter, it is recommended adjusting the L value within the range indicated below. 0.05 < 𝑉𝑂𝑈𝑇×𝑅𝐶𝑆 𝐿×106 < 0.63×𝑓𝑂𝑆𝐶 [V/μs] 106 where: 𝑉𝑂𝑈𝑇 is the DC/DC converter output voltage. 𝑅𝐶𝑆 is the current detect resistance. 𝐿 is the coil value. 𝑓𝑂𝑆𝐶 is the DC/DC oscillation frequency. Consider the deviation of L value and set with enough margins. It is more stable by reducing the value of 𝑉𝑂𝑈𝑇×𝑅𝐶𝑆 𝐿×106 , however it slows down the response time. Also, the following equation should be satisfied during coil selection in case it is used in VCC = 5 V or less. 𝐿 < 12 × 𝑉𝐶𝐶 × 𝑉𝐶𝐶 × 𝜂 𝑉𝑂𝑈𝑇 × 𝐼𝐿𝐸𝐷 × 𝑀 × 𝑓𝑂𝑆𝐶 where: 𝐿 is the coil value. 𝑉𝐶𝐶 is the supply voltage. 𝜂 is the efficiency. 𝑉𝑂𝑈𝑇 is the DC/DC converter output voltage. 𝐼𝐿𝐸𝐷 is the LED current per channel. 𝑓𝑂𝑆𝐶 is the DC/DC oscillation frequency. 𝑀 is the LED parallel number. LED intensity may drop when a coil which does not satisfy the above is chosen. www.rohm.com © 2017 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 27/41 TSZ02201-0T2T0C600300-1-2 8.Oct.2021 Rev.007 BD81A74EFV-M BD81A74MUV-M Selection of Components Externally Connected - continued 4. Selection of Voltage/Current Ratings of Coil (L), Diode (D1, D2), FET (M1, M2), RCS, and COUT Current Rating Voltage Rating Heat Loss Coil L > IL_MAX - - Diode D1 > IOCP > VCC_MAX - Diode D2 > IOCP > VOVP_MAX - FET M1 > IOCP > VCC_MAX - FET M2 > IOCP > VOVP_MAX - RCS - - > IOCP2 x RCS COUT - > VOVP_MAX - Consider deviation of external parts and set with enough margins. In order to achieve fast switching, choose the FET’s with smaller gate-capacitance. 5. Setting of Output Capacitor Select the output capacitor COUT based on the requirements of the ripple voltage VOUTpp. 𝑉𝑂𝑈𝑇𝑝𝑝 = 20×𝐼𝐿𝐸𝐷 ×𝑀 𝑓𝑂𝑆𝐶 ×𝐶𝑉𝑂𝑈𝑇 ×𝜂 + ∆𝐼𝐿 × 𝑅𝐸𝑆𝑅 [V] where: 𝑉𝑂𝑈𝑇𝑝𝑝 is the VOUT ripple voltage. 𝐼𝐿𝐸𝐷 is the LED current per channel. 𝑀 is the LED parallel number. 𝑓𝑂𝑆𝐶 is the DC/DC oscillation frequency. 𝐶𝑉𝑂𝑈𝑇 is the VOUT capacity. 𝜂 is the efficiency. ∆𝐼𝐿 is the coil current amplification. 𝑅𝐸𝑆𝑅 is the equivalent series resistance of output capacitor COUT. The actual VOUT ripple voltage is affected by PCB layout and external components characteristics. Therefore, check with the actual machine, and design a capacity with enough margins to fit in allowable ripple voltage. The maximum value of COUT that can be set is 500 µF. 6. Selection of Input Capacitor An input capacitor which is 10 μF or more with low ESR ceramic capacitor is recommended. An input capacitor which is not recommended may cause large ripple voltage at the input and hence lead to malfunction of the IC. 7. Selection of BOOT - SW Capacitor When using the Buck-Boost application or Buck application, insert 0.1 μF capacitor between the BOOT pin and the SW pin. www.rohm.com © 2017 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 28/41 TSZ02201-0T2T0C600300-1-2 8.Oct.2021 Rev.007 BD81A74EFV-M BD81A74MUV-M Selection of Components Externally Connected - continued 8. Setting of Phase Compensation Circuit COMP Pin Application Schematic(n = 1 to 4) Stability Condition of Application The stability in LED voltage feedback system is achieved when the following conditions are met. (1) When gain is 1 (0 dB), the phase delay is 150° or less (or simply, phase margin is 30° or more). (2) When gain is 1 (0 dB), the frequency (Unity Gain Frequency) is 1/10 or less of switching frequency. To assure stability based on phase margin adjustment is setting the Phase-lead fz close to unity gain frequency. In addition, the Phase-lag fp1 is decided based on COUT and output impedance RL. The respective formulas are as follows. Phase-lead 𝑓𝑧 = 1/(2𝜋𝑅𝑃𝐶 𝐶𝑃𝐶 ) [Hz] Phase-lag 𝑓𝑝1 = 1/(2𝜋𝑅𝐿 𝐶𝑂𝑈𝑇 ) [Hz] * The output impedance that is calculated in 𝑅𝐿 = 𝑉𝑂𝑈𝑇/𝐼𝑂𝑈𝑇 To make a good result, set fz between 1 kHz to 10 kHz. Substitute the value in the maximum load for RL. Further, this setting is easily obtained, and the adjustment with the actual machine may be necessary because it is not strictly calculated. In case of mass production design, thorough confirmation with the actual machine is necessary because these characteristics can change based on board layout, load condition and etc. www.rohm.com © 2017 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 29/41 TSZ02201-0T2T0C600300-1-2 8.Oct.2021 Rev.007 BD81A74EFV-M BD81A74MUV-M Selection of Components Externally Connected - continued 9. Setting of Over Voltage Protection (OVP) Over voltage protection (OVP) is set from the external resistance ROVP1, ROVP2. The setting described below is important in the either boost, buck and buck-boost applications. VOUT Internal IC ROVP2 2.0 V / 1.94 V OVP ROVP1 1.0 V / 0.57 V OVP Application Circuit The OVP pin detects the over voltage when it is 2.0 V (Typ) or more and stops the DC/DC switching. In addition, it detects the open condition when the OVP pin is at 2.0 V (Typ) or more and the LED1 to LED4 pins voltage is at 0.3 V (Typ) or less, and the circuit is latched to OFF (Refer to Protection Feature). In preventing error in detection of OPEN, it is necessary that the resistor divide voltage of the maximum value of output voltage shall be less than the minimum value of OPEN detection voltage. Set the ROVP1, ROVP2 in such a way the formula shown below can be met. 𝑉𝑂𝑈𝑇(𝑀𝑎𝑥) × (𝑅 𝑅𝑂𝑉𝑃1 𝑂𝑉𝑃1 +𝑅𝑂𝑉𝑃2 ) < 𝑉𝑂𝑉𝑃𝑜𝑝𝑒𝑛 (𝑀𝑖𝑛)……………………………………………………(1) where: 𝑉𝑂𝑈𝑇 is the DC/DC output voltage. 𝑉𝑂𝑉𝑃𝑜𝑝𝑒𝑛 is the OVP pin open detection voltage. Example 1: When Vf = 3.2 V±0.3 V LED is used in 8 series 𝑉𝑂𝑈𝑇(𝑀𝑎𝑥) = 1.1(𝐿𝐸𝐷 𝑐𝑜𝑛𝑡𝑟𝑜𝑙 𝑣𝑜𝑙𝑡𝑎𝑔𝑒 𝑀𝑎𝑥) + (3.2 + 0.3) × 8 = 29.1 [V] Open Detection OVP Pin Voltage 𝑉𝑂𝑉𝑃𝑜𝑝𝑒𝑛 (𝑀𝑖𝑛) = 1.9 [V] If ROVP1 = 20 kΩ, set by ROVP2 > 286.3 kΩ from (1). Example 2: When Vf = 3.2 V±0.3 V LED is used in 3series 𝑉𝑂𝑈𝑇(𝑀𝑎𝑥) = 1.1(𝐿𝐸𝐷 𝑐𝑜𝑛𝑡𝑟𝑜𝑙 𝑣𝑜𝑙𝑡𝑎𝑔𝑒 𝑀𝑎𝑥) + (3.2 + 0.3) × 3 = 11.6 [V] Open Detection OVP Pin Voltage 𝑉𝑂𝑉𝑃𝑜𝑝𝑒𝑛 (𝑀𝑖𝑛) = 1.9 [V] If ROVP1 = 20 kΩ, set by ROVP2 > 102.1 kΩ from (1). www.rohm.com © 2017 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 30/41 TSZ02201-0T2T0C600300-1-2 8.Oct.2021 Rev.007 BD81A74EFV-M BD81A74MUV-M Selection of Components Externally Connected - continued 10. Setting of Soft Start Time The soft start circuit is necessary to prevent increase of the coil current and overshoot of the output during the start-up. A capacitance in the range of 0.047 µF to 0.47 µF is recommended. A capacitance less than 0.047 µF may cause overshoot at the output voltage. On the other hand, a capacitance more than 0.47 µF may cause massive reverse current through the parasitic elements when power supply is OFF and may damage the IC. Soft start time tSS (Typ). [s] 𝑡𝑆𝑆 = 𝐶𝑆𝑆 × 3.3 ∕ (5 × 10−6 ) where: 𝐶𝑆𝑆 is the Capacitance at the SS pin. 11. Confirmation of Start-up Time If the PWM duty is smaller at start-up, the start-up time becomes longer. It is effective to reduce the CPC value to shorten start-up time, however, confirmation of the phase margin is necessary. PWM duty and data of startup time in typical 2 conditions are shown below. Condition 1 (Boost) VCC = 12 V, VOUT = 30 V (assume 8 LED’s series), RRT = 27 kΩ (fOSC = 300 kHz), RISET = 100 kΩ (ILED = 1000 1000 900 900 800 800 Start-up Time [ms] Start-up Time [ms] 50 mA), CPC = 0.01 µF, RPC = 5.1 kΩ, CSS = 0.1 µF, ROVP1 =2 0 kΩ, ROVP2 = 360 kΩ 700 600 500 400 300 200 600 500 400 300 200 100 100 0 700 0 0 20 40 60 PWM Duty [%] 80 100 0 0.2 0.4 0.6 PWM Duty [%] 0.8 1 Figure 21. Start-up Time(Boost) vs PWM Duty Condition 2 (Buck-Boost) VCC = 12 V, VOUT = 20 V (assume 5 LED’s series), RRT= 27 kΩ (fOSC = 300 kHz), RISET = 100 kΩ (ILED = 1000 1000 900 900 800 800 700 Start-up Time [ms] Start-up Time [ms] 50 mA), CPC = 0.01 µF, RPC = 5.1 kΩ, CSS = 0.1 µF, ROVP1 = 30 kΩ, ROVP2 = 360 kΩ 600 500 400 300 200 100 0 700 600 500 400 300 200 100 0 20 40 60 PWM Duty [%] 80 100 0 0 0.2 0.4 0.6 PWM Duty [%] 0.8 1 Figure 22. Start-up Time(Buck-Boost) vs PWM Duty The above are reference data. Always confirm by machine operation because the actual start-up time depends on layout pattern, component constant, and component characteristics. www.rohm.com © 2017 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 31/41 TSZ02201-0T2T0C600300-1-2 8.Oct.2021 Rev.007 BD81A74EFV-M BD81A74MUV-M Selection of Components Externally Connected - continued 12. Confirmation of Actual Operation Set up the external components value by procedures and attentions mentioned above. However, those settings above are not guaranteed because these are theoretically calculated and it does not include the external parts' variation or characteristics changing. The overall characteristics may change depend on power supply voltage, LED current, LED number, inductance, output capacitance, switching frequency, and PCB layout. We strongly recommend verifying your design by taking the actual measurements. Additional parts for EMC The example of EMC countermeasure components is shown in the chart below. 1. The resistance for adjusting Slew Rate of high side FET 2. The capacitor for reducing current loop noise of high side FET. 3. The capacitor for reducing noise of high frequency on power line. 4. The low pass filter for reducing noise of power line. 5. The common mode filter for reducing noise of power line. 6. The snubber circuit for reducing noise of high frequency of low side FET. 7. The snubber circuit for reducing ringing of low side FET switching. Application Circuit Reference Example (Including EMC Countermeasure Components) It is basically non-recommended to connect a capacitor to the LED1 to LED4 pins. Please refer to PCB Application Circuit. When the connection of the capacitor is necessary for noise measures, please refer to us. www.rohm.com © 2017 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 32/41 TSZ02201-0T2T0C600300-1-2 8.Oct.2021 Rev.007 BD81A74EFV-M BD81A74MUV-M Precautions on PCB Layout The layout pattern greatly affects the efficiency and ripple characteristics. Therefore, it is necessary to examine carefully when designing. As show in the figure below, Buck-Boost DC/DC converter has two loops; “Loop1” and “Loop2”. The parts in each loop have to be set as near as possible to each other. (For example, GND of C OUT and DGND should be very near, GND of CIN and GND of D1 should be very near and so on.) Moreover, the wirings of each loop should be as low impedance as possible. Figure 23. Circuit of DC/DC Block Figure 24. BD81A74MUV-M PCB TOP-layer www.rohm.com © 2017 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 33/41 TSZ02201-0T2T0C600300-1-2 8.Oct.2021 Rev.007 BD81A74EFV-M BD81A74MUV-M Calculation Example of Power Consumption (Case of Buck-Boost application) www.rohm.com © 2017 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 34/41 TSZ02201-0T2T0C600300-1-2 8.Oct.2021 Rev.007 BD81A74EFV-M BD81A74MUV-M I/O Equivalence Circuit *All values are Typ value www.rohm.com © 2017 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 35/41 TSZ02201-0T2T0C600300-1-2 8.Oct.2021 Rev.007 BD81A74EFV-M BD81A74MUV-M 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. 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 Except for pins the output and the input of which were designed to go below ground, 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. Recommended Operating Conditions The function and operation of the IC are guaranteed within the range specified by the recommended operating conditions. The characteristic values are guaranteed only under the conditions of each item specified by the electrical characteristics. 6. 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. 7. 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. 8. Inter-pin Short and Mounting Errors Ensure that the direction and position are correct when mounting the IC on the PCB. Incorrect mounting may result in damaging the IC. Avoid nearby pins being shorted to each other especially to ground, power supply and output pin. Inter-pin shorts could be due to many reasons such as metal particles, water droplets (in very humid environment) and unintentional solder bridge deposited in between pins during assembly to name a few. www.rohm.com © 2017 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 36/41 TSZ02201-0T2T0C600300-1-2 8.Oct.2021 Rev.007 BD81A74EFV-M BD81A74MUV-M Operational Notes - continued 9. 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. 10. 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 Resistor Transistor (NPN) Pin A Pin B C Pin A N P+ N P N P+ N Parasitic Elements N P+ GND E N P N P+ B N C E Parasitic Elements P Substrate P Substrate Parasitic Elements Pin B B Parasitic Elements GND GND N Region close-by GND these diodes to operate, such as applying a voltage lower than the GND voltage to an input pin (and thus to the P substrate) should be avoided. Figure 25. Example of monolithic IC structure 11. Ceramic Capacitor When using a ceramic capacitor, determine a capacitance value considering the change of capacitance with temperature and the decrease in nominal capacitance due to DC bias and others. 12. 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 maximum junction temperature 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 power output pins. When the Tj falls below the TSD threshold, the circuits are automatically restored to normal operation. Note that the TSD circuit operates in a situation that exceeds the absolute maximum ratings and therefore, under no circumstances, should the TSD circuit be used in a set design or for any purpose other than protecting the IC from heat damage. www.rohm.com © 2017 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 37/41 TSZ02201-0T2T0C600300-1-2 8.Oct.2021 Rev.007 BD81A74EFV-M BD81A74MUV-M Operational Notes - continued 13. Over Current Protection Circuit (OCP) This IC incorporates an integrated overcurrent protection circuit that is activated when the load is shorted. This protection circuit is effective in preventing damage due to sudden and unexpected incidents. However, the IC should not be used in applications characterized by continuous operation or transitioning of the protection circuit. Ordering Information B D 8 1 A 7 4 E F V - Package EFV: HTSSOP-B28 B D 8 1 A 7 4 M U M E 2 Product Rank M: for Automotive Packaging and forming specification E2: Embossed carrier tape V - Package MUV: VQFN28SV5050 M E 2 Product Rank M: for Automotive Packaging and forming specification E2: Embossed carrier tape Marking Diagram HTSSOP-B28 (TOP VIEW) VQFN28SV5050 (TOP VIEW) Part Number Marking BD81A74EFV LOT Number Part Number Marking BD81A LOT Number 74MUV Pin 1 Mark Marking Pin 1 Mark Package Orderable Part Number BD81A74EFV HTSSOP-B28 BD81A74EFV-ME2 BD81A74MUV VQFN28SV5050 BD81A74MUV-ME2 www.rohm.com © 2017 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 38/41 TSZ02201-0T2T0C600300-1-2 8.Oct.2021 Rev.007 BD81A74EFV-M BD81A74MUV-M Physical Dimension and Packing Information Package Name HTSSOP-B28 Packing Information Packing Form Embossed carrier tape Quantity 2500 pcs Direction of feed E2 www.rohm.com © 2017 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 39/41 TSZ02201-0T2T0C600300-1-2 8.Oct.2021 Rev.007 BD81A74EFV-M BD81A74MUV-M Physical Dimension and Packing Information - continued Package Name VQFN28SV5050 Packing Information Packing Form Embossed carrier tape Quantity 2500 pcs Direction of feed E2 www.rohm.com © 2017 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 40/41 TSZ02201-0T2T0C600300-1-2 8.Oct.2021 Rev.007 BD81A74EFV-M BD81A74MUV-M Revision History Date Revision 25.Sep.2017 001 Details New Release P.1 General Description Change to “Light modulation (10,000:1@100Hz dimming function) is possible by PWM input.” P.1 Key Specifications 25.Oct.2017 002 Change to “LED Maximum Dimming Ratio 10,000:1@100Hz”. P.14 PWM Minimum Pulse Width, Conditions Change to “fPWM = 100Hz to 20kHz”. P.14 PWM Frequency, Min Change to “0.1kHz”. P.1 Add words 〇This product is protected by U.S. Patent No.7,235,954, No.7,541,785, No.7,944,189. 5.Dec.2018 003 P.8 Add “(8) DC/DC switching control at over voltage output (LSDET)” and " (9) PWM pulse and DC/DC switching" 2.Sep.2019 004 P.5 Add Format update Change the sentence about "Spread Spectrum Function" (Before) The band of the switching frequency becomes 90 %±10 % of … (After) The band of the switching frequency becomes 100 % to 80 % … Change the calculation of noise reduction S. 10.Apr.2020 005 Added Figure19, Figure20 and calculation. Added the following sentence to the description of "PCB Application Circuit Diagram" When PWM min pulse width satisfies the following formula, please do not connect a capacitor to LED1 to LED4 pins. It might misdetect LED short protection. When the connection of the capacitor is necessary for noise measures, please refer to us. tMIN ≤ 10/fOSC tMIN : PWM min pulse width fOSC : DCDC frequency target Added the following sentence to "Selection of Components Externally Connected"/"Confirmation of Actual Operation" It is basically non-recommended to connect a capacitor to the LED1 to LED4 pins. Please refer to PCB Application Circuit. When the connection of the capacitor is necessary for noise measures, please refer to us. 12.Feb.2021 006 P.7 Figure 4 X axis name Before：RRT [Ω] After：RRT [kΩ] 8.Oct.2021 007 P.1 Typical Application Circuit Modified the right side of the figure broke off. www.rohm.com © 2017 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 41/41 TSZ02201-0T2T0C600300-1-2 8.Oct.2021 Rev.007 Notice Precaution on using ROHM Products 1. If you intend to use our Products in devices requiring extremely high reliability (such as medical equipment (Note 1), aircraft/spacecraft, nuclear power controllers, etc.) and whose malfunction or failure may cause loss of human life, bodily injury or serious damage to property (“Specific Applications”), please consult with the ROHM sales representative in advance. Unless otherwise agreed in writing by ROHM in advance, ROHM shall not be in any way responsible or liable for any damages, expenses or losses incurred by you or third parties arising from the use of any ROHM’s Products for Specific Applications. (Note1) Medical Equipment Classification of the Specific Applications JAPAN USA EU CHINA CLASSⅢ CLASSⅡb CLASSⅢ CLASSⅢ CLASSⅣ CLASSⅢ 2. ROHM designs and manufactures its Products subject to strict quality control system. However, semiconductor products can fail or malfunction at a certain rate. Please be sure to implement, at your own responsibilities, adequate safety measures including but not limited to fail-safe design against the physical injury, damage to any property, which a failure or malfunction of our Products may cause. The following are examples of safety measures: [a] Installation of protection circuits or other protective devices to improve system safety [b] Installation of redundant circuits to reduce the impact of single or multiple circuit failure 3. Our Products are not designed under any special or extraordinary environments or conditions, as exemplified below. Accordingly, ROHM shall not be in any way responsible or liable for any damages, expenses or losses arising from the use of any ROHM’s Products under any special or extraordinary environments or conditions. If you intend to use our Products under any special or extraordinary environments or conditions (as exemplified below), your independent verification and confirmation of product performance, reliability, etc, prior to use, must be necessary: [a] Use of our Products in any types of liquid, including water, oils, chemicals, and organic solvents [b] Use of our Products outdoors or in places where the Products are exposed to direct sunlight or dust [c] Use of our Products in places where the Products are exposed to sea wind or corrosive gases, including Cl2, H2S, NH3, SO2, and NO2 [d] Use of our Products in places where the Products are exposed to static electricity or electromagnetic waves [e] Use of our Products in proximity to heat-producing components, plastic cords, or other flammable items [f] Sealing or coating our Products with resin or other coating materials [g] Use of our Products without cleaning residue of flux (Exclude cases where no-clean type fluxes is used. However, recommend sufficiently about the residue.); 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-PAA-E © 2015 ROHM Co., Ltd. All rights reserved. Rev.004 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 Cl 2, 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 A two-dimensional barcode 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-PAA-E © 2015 ROHM Co., Ltd. All rights reserved. Rev.004 Datasheet General Precaution 1. Before you use our Products, you are requested to carefully read this document and fully understand its contents. ROHM shall not be in any way responsible or liable for failure, malfunction or accident arising from the use of any ROHM’s Products against warning, caution or note contained in this document. 2. All information contained in this document is current as of the issuing date and subject to change without any prior notice. Before purchasing or using ROHM’s Products, please confirm the latest information with a ROHM sales representative. 3. The information contained in this document is provided on an “as is” basis and ROHM does not warrant that all information contained in this document is accurate and/or error-free. ROHM shall not be in any way responsible or liable for an y damages, expenses or losses incurred b y you or third parties resulting from inaccuracy or errors of or concerning such information. Notice – WE © 2015 ROHM Co., Ltd. All rights reserved. Rev.001