Datasheet 12V to 76V input voltage range 3A output current 1ch Buck Converter Integrated FET BD9G341AEFJ General Description The BD9G341AEFJ is a buck switching regulator with integrated 150mΩ power MOSFET. Current mode architecture provides fast transient response and a simple phase compensation setup. The operating frequency is programmable from 50kHz to 750kHz. Additional protection features are included such as Over Current Protection, Thermal shutdown and Under voltage lockout. The under voltage lockout and hysteresis can be set by external resistor . Key specifications ■ Input voltage ■ Ref voltage(Ta=25°C) (Ta=-40 to 85°C) ■ Max output current ■ Operating Temperature ■ Max junction temperature Package(s) Features 12 to 76[V] ±1.5[%] ±2.0[%] 3 [A] (Max.) -40°C to 85°C 150°C HTSOP-J8 Wide input voltage range from 12V to 76V. Integrated 80V/3.5A/150mΩ NchFET. Current mode. Variable frequency from 50kHz to 750kHz. Accurate reference voltage.( 1.0 V±1.5 %). Precision EN threshold ( ±3%). Soft-start function 0uA Standby current Over Current Protection (OCP), Under Voltage Lockout(UVLO), Thermal-Shutdown(TSD),Over Voltage Protection (OVP) Thermally enhanced HTSOP-J8 package 4.90mm x 6.00mm x 1.00mm Applications Industrial distributed power applications. Automotive Application Battery powered equipment. Typical Application Circuit 0.1uF Vin=12～76V VCC C1: 10uF/100V L : 33uH BST VOUT=5.0V /3A LX R1 Ω D1 3.0kΩ EN C2: 100uF/6.3V FB VC R2 Ω GND RT 0.75kΩ 6800pF 47kΩ 10kΩ Figure 1. Typical Application Schematic 〇Product structure : Silicon monolithic integrated circuit .www.rohm.com © 2015 ROHM Co., Ltd. All rights reserved. TSZ22111 • 14 • 001 〇This product has no designed protection against radioactive rays 1/26 TSZ02201-0Q3Q0AJ00480-1-2 16.Dec.2015 Rev.003 BD9G341AEFJ Pin Configuration LX 1 8 VCC GND 2 7 BST Thermal Pad VC 3 6 EN FB 4 5 RT Figure 2.Pin Configuration (TOP VIEW) Pin Description Pin No. Pin Name 1 LX 2 GND 3 VC The output of the internal error amplifier. The phase compensation implementation is connected between this pin to GND. 4 FB Voltage feedback pin. This pin is the error-amp input with the DC voltage is set at 1.0V with feed-back operation. 5 RT 6 EN 7 BST 8 VCC - Thermal Pad www.rohm.com © 2015 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 Description Switching node. It should be connected as near as possible to the schottky barrier diode, and inductor. Ground pin. GND pattern is kept from the current line of input capacitor to output capacitor. The internal oscillator frequency set pin. The internal oscillator is set with a single resistor connected between this pin and the GND pin. Recommended frequency range is 50kHz to 750kHz Shutdown pin. If the voltage of this pin is below 1.3V,the regulator will be in a low power state. If the voltage of this pin is between 1.3V and 2.4V. The IC will be in standby mode. If the voltage of this pin is above 2.6V, the regulator is operational. An external voltage divider can be used to set under voltage threshold. If this pin is left open circuit. when converter is operating. This pin output 10uA source current. If this pin is left open circuit, a 10uA pull up current source configures the regulator fully operational. Boost input for bootstrap capacitor The external capacitor is required between the BST and the Lx pin. A 0.1uF ceramic capacitor is recommended. Input supply voltage pin. Connect to GND. 2/26 TSZ02201-0Q3Q0AJ00480-1-2 16.Dec.2015 Rev.003 BD9G341AEFJ Block Diagram ON/OFF EN 10uA VCC STANBY ↓ TSD UVLO Reference + REG VREF 2.6V shutdown VC OCP Current Sense AMP OVP FB 1.0V BST + + Error AMP Σ Current Comparator R Q + S 0.15Ω LX Soft Start VOUT 20Ω Soft Start Oscillator Oscillator 20Ω GND RT Figure 3.Block Diagram Description of Block(s) 1. Reference This block generates inner reference voltage. 2. REG This block generates 8V reference voltage for bootstrap. 3. OSC This block generates inner CLK. The internal oscillator is set with a single resistor connected between this pin and the GND pin. Recommended frequency range is 50 kHz to 750 kHz. If RT pin connect to 47kohm, frequency is set 200 kHz. 4. Soft Start Soft Start of the output voltage of regulator prevents in-rush current during Start-up. Soft Start time is 20msec (typ) 5. ERROR AMP This is an error amplifier what detects output signal, and outputs PWM control signal. Internal reference voltage is set to 1.0V. 6. ICOMP This is a comparator that outputs PWM signal from current feed-back signal and error-amp output for current-mode. 7. Nch FET SW This is a 80V/150mΩ-Power Nch MOSFET SW that converts inductor current of DC/DC converter Since the current rating of this FET is 3.5A, it should be used within 3.5A including the DC current and ripple current of the coil. 8. UVLO This is a Low Voltage Error Prevention Circuit. This prevents internal circuit error during increase of Power supply Voltage and during decline of Power supply Voltage. It monitors VCC Pin Voltage and internal REG Voltage, When VCC Voltage becomes 11V and below, UVLO turns OFF all Output FET and turns OFF the DC/DC Comparator Output, and the Soft Start Circuit resets. Now this Threshold has Hysteresis of 200mV. www.rohm.com © 2015 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 3/26 TSZ02201-0Q3Q0AJ00480-1-2 16.Dec.2015 Rev.003 BD9G341AEFJ 9. EN Shutdown function. If the voltage of this pin is below 1.3V, the regulator will be in a low power state. If the voltage of this pin is between 1.3V and 2.4V will be standby mode. If the voltage of this pin is above 2.6V, the regulator is operational. An external voltage divider can be used to set under voltage threshold. If this pin is left open circuit. when converter is operating. This pin output 10uA source current. If this pin is left open circuit, a 10uA pull up current source configures the regulator fully operational. When IC turn off, EN pin is pulled down by pull down resistor that sink above 10uA. 10. OCP Over current protection If the current of power MOSFET is over 6.0A (typ), this function reduces duty pulse –by- pulse and restricts the over current. If IC detects OCP 2 times sequentially, the device will stop and after 20 msec restart. 11. TSD This is Thermal Shutdown Detection When it detects an abnormal temperature exceeding Maximum Junction Temperature (Tj=150°C), it turns OFF all Output FETs, and turns OFF the DC/DC Comparator Output. When Temperature falls, and the IC automatically returns 12. OVP Over voltage protection. Output voltage is monitored with FB terminal, and output FET is turned off when it becomes 120% of set-point voltage. Absolute Maximum Ratings Item Symbol Ratings Unit Maximum input voltage VCC 80 V BST to GND VBST 85 V Maximum input current Imax 3.5 A BST to LX ⊿VBST 15 V EN to GND VEN 80 V LX to GND VLX 80 V FB to GND VFB 7 V Power Dissipation Pd 3.76 (NOTE1) W Operating Temperature Topr -40 to +85 °C Storage Temperature Tstg -55 to +150 °C Junction Temperature Tjmax 150 °C (NOTE1)During mounting of 70×70×1.6t mm 4layer board.Reduce by 5.4mW for every 1°C increase..(Above 25°C) www.rohm.com © 2015 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 4/26 TSZ02201-0Q3Q0AJ00480-1-2 16.Dec.2015 Rev.003 BD9G341AEFJ Electrical Characteristics (Unless otherwise specified Ta=25°C, VCC=48V, Vo=5V,EN=3V,RT=47kΩ ) Parameter Symbol Limit Min Typ Unit Max Condition 【Circuit Current】 Stand-by current of VCC Ist ― 0 10 µA VEN=0V Circuit current of VCC Icc ― 1.5 2.0 mA FB=1.5V Detect Voltage Vccuv 10.4 11 11.6 V Hysteresis width Vuvhy ― 200 300 mV VFBN 0.985 1.000 1.015 V VFBA IFB Isource Isink Tsoft AVEA 0.980 -1 15 -65 15 ― 1.000 0 40 -40 20 10000 1.020 1 65 -15 25 ― V uA uA uA msec V/V GEA ― 300 ― µA/V GCS ― 10 ― A/V 【Under Voltage Lock Out (UVLO)】 【Error Amp】 FB threshold voltage FB Input bias current VC source current VC sink current Soft start time Error amplifier DC gain Trans conductance Ta=25°C Ta=-40 to 85°C VFB=2.0V 【Current Sense Amp 】 VC to switch current trans conductance 【OCP】 Iocp 3.5 6.0 ― A OCP latch count NOCP ― 2 ― count OCP latch hold time TOCP 15 20 25 msec RonH ― 150 ― mΩ VENON 1.3 ― 2.4 V Venuv IEN 2.52 9.0 2.6 10.0 2.68 11.0 V µA Fosc Toff 180 ― 200 ― 220 500 kHz nsec Detect current 【Output】 Lx NMOS ON resistance 【CTL】 EN Pin inner REG on voltage EN Pin IC output on threshold EN pin 【Oscillator】 Oscillator frequency Forced off time ON IC on or off threshold VEN=3V RT:R=47kΩ Recommended Operating Ratings(Ta=25°C) Item Power Supply Voltage Symbol VCC Rating Min Typ Max 12 ― 76 (Note2) 1.0 ― (Note3) VCC Unit V Output voltage VOUT Output current IOUT - ― 3.0 V A Oscillator frequency Fosc 50 ― 750 kHz (Note2) Restricted by minduty=f×MinOn Time ( f :frequency) If the voltage of Vcc×minduty [V] lower than 1V, this value is minimum output. (Note3) Restricted by maxduty =1-f×forced off time The maximum output is Vcc×maxduty – Iout*Ron Ron:。 www.rohm.com © 2015 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 5/26 TSZ02201-0Q3Q0AJ00480-1-2 16.Dec.2015 Rev.003 BD9G341AEFJ Typical Performance Characteristics 220 1.02 215 1.015 210 1.01 FB THRESHOLD [V] FREQUENCY [kHz] (Unless otherwise specified, Ta=25°C，VCC=24V, VOUT=5V) 205 200 195 190 185 1.005 1 0.995 0.99 0.985 180 0.98 -50 0 50 100 12 TEMPERATURE [℃ ] 72 Fig.5 FB Threshold Voltage- Input Voltage 1.02 500 1.015 480 FORCED OFF TIME [n sec] FB THRESHOLD [V] 52 INPUT VOLTAGE[V] Fig.4 Oscillator Frequency - Temperature 1.01 1.005 1 0.995 0.99 0.985 460 440 420 400 380 360 340 320 0.98 300 -50 0 50 100 -50 TEMPERATURE [℃ ] 0 50 100 TEMPERATURE [℃ ] Fig.7 Forced off time - Temperature Fig.6 FB Threshold Voltage - Temperature 12 8 11.8 7.5 11.6 7 OCP THRESHOLD [A] UVLO THRESHOLD [V] 32 11.4 11.2 11 10.8 10.6 10.4 10.2 6.5 6 5.5 5 4.5 4 10 3.5 -50 0 50 100 -50 TEMPERATURE [℃ ] 50 100 TEMPERATURE [℃ ] Fig.8 UVLO Threshold Voltage - Temperature www.rohm.com © 2015 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 0 Fig.9 OCP Detect Current - Temperature 6/26 TSZ02201-0Q3Q0AJ00480-1-2 16.Dec.2015 Rev.003 BD9G341AEFJ EN PIN INNER REG THRESHOLD [V] 25 SOFT START TIME [msec] 24 23 22 21 20 19 18 17 16 15 -50 0 50 2.3 2.1 1.9 1.7 1.5 1.3 -50 100 50 100 TEMPERATURE [℃ ] TEMPERATURE [℃ ] Fig.11 EN Pin Inner REG ON Threshold - Temperature Fig.10 Soft Start Time - Temperature 11 EN UVLO SOURCE CURRENT[uA] 2.7 EN UVLO THRESHOLD [V] 0 2.65 2.6 2.55 10.8 10.6 10.4 10.2 10 9.8 9.6 9.4 9.2 9 2.5 -50 0 50 -50 100 0 50 100 TEMPERATURE [℃ ] TEMPERATURE [℃ ] Fig.13 EN Source Current - Temperature Fig.12 ENUVLO Threshold - Temperature Fig.14 NMOS ON Resistance -Temperature www.rohm.com © 2015 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 7/26 TSZ02201-0Q3Q0AJ00480-1-2 16.Dec.2015 Rev.003 BD9G341AEFJ Reference Characteristics of Typical Application Circuits Vout=5V , f=200kHz 0.1uF Vin=12～76V VCC C1: 10uF/100V L : 33uH BST VOUT=5.0V /3A LX R1 Ω D1 3.0kΩ EN C2: 100uF/6.3V FB VC R2 Ω GND 0.75kΩ RT 6800pF 10kΩ 47kΩ Parts ： ：SUMIDA CDRH129HF C1 ：TDK C5750X7S2A106K 10μF/100V C2 ：TDK C4532X5R0J107M 100μF/6.3V D1 ：Rohm RB095B-90 L 33μH 100 90 VCC=24V 80 48V EFFICIENCY [%] 70 60 50 60V 40 76V 30 20 10 0 1 10 100 1000 OUTPUT CURRENT[mA] Fig.15 Efficiency – Output Current www.rohm.com © 2015 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 8/26 TSZ02201-0Q3Q0AJ00480-1-2 16.Dec.2015 Rev.003 BD9G341AEFJ VEN [5V/div] Io [500mA/div] Vout [2V/div] Overshoot Voltage: 150mV VLx [10V/div] Vout [100mV/div] ILx [0.5A/div] Undershoot Voltage: 230mV 5msec/div 2msec/div Fig.16 Start-up Characteristics Fig.17 Load Response Iout:100mA ⇔1A Vout:offset 5V 40mV/div Vout:offset 5V 40mV/div Vout Ripple :24mV Vout Ripple :32mV 5usec/div 10usec/div Fig.18 Lx Switching/Vout Ripple Io = 100mA Fig.19 Lx Switching/Vout Ripple Io=1A Phase Phase Gain Gain Fig.20 Frequency Response Io=100mA www.rohm.com © 2015 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 Fig.21 Frequency Response Io=3.0A 9/26 TSZ02201-0Q3Q0AJ00480-1-2 16.Dec.2015 Rev.003 BD9G341AEFJ Reference Characteristics of Typical Application Circuits Vout=3.3V , f=200kHz 0.1uF Vin=12～76V VCC C1: 10uF/100V L : 33uH BST VOUT=3.3V /3A LX R1 Ω D1 1.3kΩ EN C2: 100uF/6.3V FB 0.56kΩ VC R2 Ω GND 0.01uF RT 47kΩ Parts ： 6.2kΩ ：SUMIDA CDRH129HF C1 ：TDK C5750X7S2A106K 10μF/100V C2 ：TDK C4532X5R0J107M 100μF/6.3V D1 ：Rohm RB095B-90 L 33μH 100 90 VCC=24V 80 EFFICIENCY [%] 70 48V 60 50 60V 40 30 76V 20 10 0 1 10 100 1000 OUTPUT CURRENT[mA] Fig.22 Efficiency – Output Current www.rohm.com © 2015 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 10/26 TSZ02201-0Q3Q0AJ00480-1-2 16.Dec.2015 Rev.003 BD9G341AEFJ Io [500mA/div] VEN [5V/div] Vout [2V/div] Overshoot Voltage: 140mV VLx [10V/div] Vout [100mV/div] ILx [0.5A/div] Undershoot Voltage: 200mV 5msec/div 2msec/div Fig.23 Start-up Characteristics Fig.24 Load Response Iout:100mA ⇔1A Vout:offset 3.3V 40mV/div Vout:offset 3.3V 40mV/div Vout Ripple :24mV Vout Ripple :32mV 10usec/div 5usec/div Fig.25 Lx Switching/Vout Ripple Io = 100mA Fig.26 Lx Switching/Vout Ripple Io=1A Phase Phase Gain Gain Fig.27 Frequency Response Io=100mA www.rohm.com © 2015 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 Fig.28 Frequency Response Io=3A 11/26 TSZ02201-0Q3Q0AJ00480-1-2 16.Dec.2015 Rev.003 BD9G341AEFJ Detailed Description ◇Frequency setting Arbitrary internal oscillator frequency setup is possible by connecting RT resistance. Recommended frequency range is 50 kHz to 750 kHz. For setting frequency f [Hz] 、RT resistance is looked for using the following formula. 1 400 10 9 f RT [Ω ] 96.48 10 12 If setting frequency is 200kHz, RT is 47kΩ. RT resistance is related to frequency as shown in Figure 26. 1000 900 FREQUENCY [kHz] 800 700 600 500 400 300 200 100 0 5 50 RT resistance [k ohm] Fig.29 Oscillator Frequency - RT resistance ◇External UVLO threshold The high precision reset function is built in EN terminal of BD9G341AEFJ, and arbitrary low-voltage malfunction prevention setup is possible by connecting EN pin to resistance division of input voltage. When you use, please set R1 and R2 to arbitrary voltage of IC turned on (Vuv) and hysteresis (Vuvhys) like below. 0.1uF Vin=Vuv～76V VCC C1: 10uF/100V L : 33uH BST VOUT=5.0V /3A LX R1 Ω D1 3.0kΩ EN C2: 100uF/6.3V FB VC R2 Ω GND RT 0.75kΩ 6800pF 47kΩ 10kΩ Fig.30 External UVLO setup R1= Vuvhys IEN [ohm] R2= VEN×R1 Vuv-VEN [ohm] IEN:EN pin source current 10uA(typ) VEN: EN pin output on threshold 2.6V(typ) As an example in typical sample, When Vcc voltage which IC turned on 15V, Hysteresis width 1V, The resistance divider set to R1=100kΩ,R2=20kΩ. www.rohm.com © 2015 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 12/26 TSZ02201-0Q3Q0AJ00480-1-2 16.Dec.2015 Rev.003 BD9G341AEFJ ◇OCP operation The device has over current protection for protecting the FET from over current. To detect OCP 2 times sequentially, the device will stop and after 20msec restart. OCP threshold VC VC voltage discharged by OCP latch VC voltage rising by output connect to GND force the High side FET OFF by detecting OCP current (pulse by pulse protection) Lx output connect to GND VOUT OCP set the OCP latch by detecting the OCP current 2 times sequencially OCP latch reset after 1320msec msec (300ｋHz 4000 counts) OCP_LATCH Fig.31 Timing chart at OCP operation ◇start up with output pre-bias voltage It starts in the state that the voltage remains in the output , in the cases that big capacitor is connected to output , IC discharge output voltage min 7.5V by FET ON 300nsec in period to charge bootstrap capacitor between BST to LX. When it is necessary to make a startup sequence, Please forcibly discharge the output voltage. Vout 5.0V/div Discharge output LX 20V/div 5msec /div Figure 32. pre-bias start up waveform VCC=48V Vout=24V www.rohm.com © 2015 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 13/26 TSZ02201-0Q3Q0AJ00480-1-2 16.Dec.2015 Rev.003 BD9G341AEFJ ◇Restriction of output Bias application The application that output connects to the other power supply is not recommended because the output voltage is not discharged in startup. Vin VCC BST Vout Vbias LX R1 Ω Load EN FB VC R2 Ω GND RT Figure 33. Output Bias NG application When output connect to voltage supply, Please insert a diode to the IC output side. Vin VCC BST Vout Vbias LX R1 Ω Load EN FB VC R2 Ω GND RT Figure 34. Output Bias OK application www.rohm.com © 2015 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 14/26 TSZ02201-0Q3Q0AJ00480-1-2 16.Dec.2015 Rev.003 BD9G341AEFJ ●Application Components Selection Method (1) Inductors Something of the shield type that fulfills the current rating (Current value Ipeak below), with low DCR is recommended. Value of Inductance influences Inductor Ripple Current and becomes the cause of Output Ripple. In the same way as the formula below, this Ripple Current can be made small for as big as the L value of Coil or as high as the Switching Frequency. IL ・・・ (1) 2 VCC VOUT VOUT 1 IL L VCC f Δ IL Ipeak IOUT Fig.35 inductor Current ・・・ (2) (⊿IL: Output Ripple Current, VCC: Input Voltage, VOUT: Output Voltage, f: Switching Frequency) For design value of Inductor Ripple Current, please carry out design tentatively with about 20% to 50% of Maximum Input Current. In the BD9G341AEFJ, it is recommended the below series of 4.7μH to 33μH inductance value. Recommended Inductor：SUMIDA CDRH129HF Series (2) Output Capacitor In order for capacitor to be used in output to reduce output ripple, Low ceramic capacitor of ESR is recommended. Also, for capacitor rating, on top of putting into consideration DC Bias characteristics, please use something whose maximum rating has sufficient margin with respect to the Output Voltage. Output ripple voltage is looked for using the following formula. VPP IL 1 IL RESR 2 f COUT ・・・ (3) Please design in a way that it is held within Capacity Ripple Voltage. In the BD9G341AEFJ, it is recommended a ceramic capacitor over 10μF. The maximum value of the output capacitor is limited by Start up Rush current The rush current is expressed by the following (Rush Current )=（Current of the error amplifier reply delay）+ Cout Vout Tsoftstart_ min +Ripple Current +Output Current (Out put Capacitor Charge current) Current of the error amplifier reply delay depend on the phase compensation element and output capacitor. As output capacitor big, Rush Current grows big. Please verify actual equipments that the Rush Current become smaller than OCP Threshold(min3.5A). www.rohm.com © 2015 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 15/26 TSZ02201-0Q3Q0AJ00480-1-2 16.Dec.2015 Rev.003 BD9G341AEFJ VOUT (3) Output voltage setting ERROR AMP R1 The internal reference voltage of ERROR AMP is 1.0V. Output voltage is determined like (4) types. FB R2 VOUT R1 R 2 R2 ・・・ (4) VREF 1.0 V Fig.36 Output voltage setting (4) Bootstrap Capacitor Please connect from 0.1uF (Laminate Ceramic Capacitor) between BST Pin and Lx Pins. (5) Catch Diode BD9G341AEFJ should be taken to connect external catch diode between Lx Pin and GND Pin. The diode require adherence to absolute maximum Ratings of application. Opposite direction voltage should be higher than maximum voltage of Lx Pin (VCCMAX + 0.5V). The peak current is required to be higher than IOUTMAX +⊿IL. (6) Input Capacitor BD9G341AEFJ needs an input decoupling capacitor. It is recommended a low ceramic capacitor ESR over 4.7μF. Additionally, it should be located as close as possible. Capacitor should be selected by maximum input voltage with input ripple voltage. Input ripple voltage is calculated by using the following formula. VCC IOUT VOUT VOUT ・・・ 1f CVCC VCC VCC (5) CVCC: Input capacitor RMS ripple current is calculated by using the following formula. VOUT VOUT (1 ) VCC VCC ICVCC IOUT ・・・ (6) If VCC=2VOUT, RMS ripple current is maximum. That is determined by (9) . ICVCC_max IOUT 2 ・・・ (7) (7) About Adjustment of DC/DC Comparator Frequency Characteristics Role of Phase compensation element C1, C2, R3 0.1uF VCC L : 33uH BST VOUT=5.0V /3A LX 10uF/100V R1 Ω D1 3.0kΩ 100uF/6.3V EN FB VC R2 Ω GND RT 0.75kΩ C1 47kΩ C2 R3 Fig.37 Feedback voltage resistance setting method www.rohm.com © 2015 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 16/26 TSZ02201-0Q3Q0AJ00480-1-2 16.Dec.2015 Rev.003 BD9G341AEFJ Stability and Responsiveness of Loop are controlled through VC Pin which is the output of Error Amp. The combination of zero and pole that determines Stability and Responsiveness is adjusted by the combination of resistor and capacitor that are connected in series to the VC Pin. DC Gain of Voltage Return Loop can be calculated for using the following formula. Adc Rl G CS A VEA VFB VOUT ・・・ (8) Here, VFB is Feedback Voltage (1.0V).AEA is Voltage Gain of Error amplifier (typ: 55.6dB), Gcs is the Trans-conductance of Current Detect (typ: 10A/V), and Rl is the Output Load Resistance value. There are 2 important poles in the Control Loop of this DC/DC. The first occurs with/ through the output resistance of Phase compensation Capacitor (C1) and Error amplifier. The other one occurs with/through the Output Capacitor and Load Resistor. These poles appear in the frequency written below. fp1 G EA 2 C1 A VEA fp 2 1 2 COUT Rl ・・・ (9) ・・・ (10) Here, GEA is the trans-conductance of Error amplifier (typ: 300 µA/V). Here, in this Control Loop, one zero becomes important. With the zero which occurs because of Phase compensation Capacitor C1 and Phase compensation Resistor R3, the Frequency below appears. fz1 1 2 C1 R3 ・・・ (11) Also, if Output Capacitor is big, and that ESR (RESR) is big, in this Control Loop, there are cases when it has an important, separate zero (ESR zero). This ESR zero occurs due to ESR of Output Capacitor and Capacitance, and exists in the Frequency below. fz ESR 1 2 COUT RESR ・・・ (12) (ESR zero) In this case, the 3rd pole determined with the 2nd Phase compensation Capacitor (C2) and Phase Correction Resistor (R3) is used in order to correct the ESR zero results in Loop Gain. This pole exists in the frequency shown below. fp 3 1 2 C2 R3 ・・・ (13) (Pole that corrects ESR zero) The target of Phase compensation design is to create a communication function in order to acquire necessary band and Phase margin. Cross-over Frequency (band) at which Loop gain of Return Loop becomes “0” is important. When Cross-over Frequency becomes low, Power supply Fluctuation Response, Load Response, etc worsens. On the other hand, when Cross-over Frequency is too high, instability of the Loop can occur. Tentatively, Cross-over Frequency is targeted to be made 1/20 or below of Switching Frequency. Selection method of Phase Compensation constant is shown below. 1. Phase Compensation Resistor (R3) is selected in order to set to the desired Cross-over Frequency. Calculation of RC is done using the formula below. R3 2 COUT fc VOUT GEA G CS VFB www.rohm.com © 2015 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 ・・・ (14) 17/26 TSZ02201-0Q3Q0AJ00480-1-2 16.Dec.2015 Rev.003 BD9G341AEFJ Here, fc is the desired Cross-over Frequency. It is made about 1/20 and below of the Normal Switching Frequency (fs). 2. Phase compensation Capacitor (C1) is selected in order to achieve the desired phase margin. In an application that has a representative Inductance value (about several 4.7µH to 33µH), by matching zero of compensation to 1/4 and below of the Cross-over Frequency, sufficient Phase margin can be acquired. C1 can be calculated using the following formula. C1 3. 4 2 R3 fc ・・・ (15) Examination whether the second Phase compensation Capacitor C2 is necessary or not is done. If the ESR zero of Output Capacitor exists in a place that is smaller than half of the Switching Frequency, a second Phase compensation Capacitor is necessary. In other words, it is the case wherein the formula below happens. 1 fs 2 COUT RESR 2 ・・・ (16) In this case, add the second Phase compensation Capacitor C2, and match the frequency of the third pole to the Frequency fp3 of ESR zero. C2 COUT RESR R3 www.rohm.com © 2015 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 ・・・ (17) 18/26 TSZ02201-0Q3Q0AJ00480-1-2 16.Dec.2015 Rev.003 BD9G341AEFJ PCB Layout Layout is a critical portion of good power supply design. There are several signals paths that conduct fast changing currents or voltages that can interact with stray inductance or parasitic capacitance to generate noise or degrade the power supplies performance. To help eliminate these problems, the VCC pin should be bypassed to ground with a low ESR ceramic bypass capacitor with B dielectric. Care should be taken to minimize the loop area formed by the bypass capacitor connections, the VCC pin, and the anode of the catch diode. See Fig.28 for a PCB layout example. The GND pin should be tied directly to the thermal pad under the IC and the thermal pad. In order to reduce the influence of the impedance and L of the parasitic, the high current line is thick and short. Input decoupling capacitor should be located as close to the VCC pins In order to minimize the parasitic capacitor and impedance of pattern, catch diode and inductance should be located as close to the Lx pin. The thermal pad should be connected to any internal PCB ground planes using multiple VIAs directly under the IC. GND feedback resistor, phase compensation element and RT resistor don’t give the common impedance resistor against high current line. VOUT Output Capacitor Inductor Topside Ground Area Catch Diode Compensation Network LX VCC GND BST VC EN FB RT Input Bypass Capacitor VCC Route BST Capacitor Trace on another layer to provide with wide path for topside ground Resistor Divider Signal VIA Thermal VIA Figure 38. Evaluation Board Pattern www.rohm.com © 2015 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 19/26 TSZ02201-0Q3Q0AJ00480-1-2 16.Dec.2015 Rev.003 BD9G341AEFJ Power Dissipation It is shown below reducing characteristics of power dissipation to mount 70mm×70mm×1.6mmt PCB Junction temperature must be designed not to exceed 150°C. 4000 ④3760mW HTSOP-J8 Package On 70mm×70mm×1.6mm t glass epoxy PCB ①1-layer board （Backside copper foil area 0mm×0mm） ②2-layer board ( Backside copper foil area 15mm×15mm) ③2-layer board （Backside copper foil area 70mm×70mm） ④4-layer board （Backside copper foil area 70mm×70mm） POWER DISSIPATION - mW 3500 3000 2500 ③2210mW 2000 1500 ②1100mW 1000 ①820mW 500 0 0 25 50 75 100 125 150 Ambient Temperature - ℃ Figure 39.Power Dissipation Characteristic Power Dissipation Estimate The following formulas show how to estimate the device power dissipation under continuous mode operations. They should not be used if the device is working in the discontinuous conduction mode. The device power dissipation includes: 1) Conduction loss：Pcon = IOUT2 × RonH × VOUT/VCC 2) Switching loss： Psw = 16n × VCC × IOUT × fsw 3) Gate charge loss：Pgc = 500p×7×fsw 4) Quiescent current loss：Pq = 1.5m × VCC Where: IOUT is the output current (A）, RonH is the on-resistance of the high-side MOSFET（Ω）, VOUT is the output voltage (V). VCC is the input voltage (V) fsw is the switching frequency (Hz). Therefore Power dissipation of IC is the sum of above dissipation. Pd = Pcon + Psw + Pgc + Pq For given Tj, Tj =Ta + θja × Pd Where: Pd is the total device power dissipation (W), Ta is the ambient temperature (°C) Tj is the junction temperature (°C), θja is the thermal resistance of the package (°C) www.rohm.com © 2015 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 20/26 TSZ02201-0Q3Q0AJ00480-1-2 16.Dec.2015 Rev.003 BD9G341AEFJ I/O Equivalent Schematic Pin. No Pin. Name Pin Equivalent Schematic Pin. No Pin. Name 5 RT Pin Equivalent Schematic BST 1 Lx 2 GND 7 BST 8 VCC VCC RT LX GND GND VCC 3 VC VC 6 GND EN EN GND FB 4 FB GND www.rohm.com © 2015 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 21/26 TSZ02201-0Q3Q0AJ00480-1-2 16.Dec.2015 Rev.003 BD9G341AEFJ 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. OR 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. The absolute maximum rating of the Pd stated in this specification is when the IC is mounted on a 70mm x 70mm x 1.6mm glass epoxy board. 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. www.rohm.com © 2015 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 22/26 TSZ02201-0Q3Q0AJ00480-1-2 16.Dec.2015 Rev.003 BD9G341AEFJ Operational Notes – continued 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. 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 40. Example of monolithic IC structure 13. Ceramic Capacitor When using a ceramic capacitor, determine the dielectric constant considering the change of capacitance with temperature and the decrease in nominal capacitance due to DC bias and others. 14. 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). Operational Notes – continued 15. 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. 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. 16. 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. www.rohm.com © 2015 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 23/26 TSZ02201-0Q3Q0AJ00480-1-2 16.Dec.2015 Rev.003 BD9G341AEFJ Ordering Information B D 9 G 3 Part Number 4 1 A E Package EFJ: HTSOP-J8 F J - E2 Packaging and forming specification : Embossed tape and reel Marking Diagrams HTSOP-J8 4.90mm x 6.00mm x 1.00mm HTSOP-J8 (TOP VIEW) HTSOP-J8(TOP VIEW) Part Number Marking 9 G 3 4 1 A LOT Number 1PIN MARK www.rohm.com © 2015 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 24/26 TSZ02201-0Q3Q0AJ00480-1-2 16.Dec.2015 Rev.003 BD9G341AEFJ Physical Dimension, Tape and Reel Information Package Name www.rohm.com © 2015 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 HTSOP-J8 25/26 TSZ02201-0Q3Q0AJ00480-1-2 16.Dec.2015 Rev.003 BD9G341AEFJ Revision History Date Revision 15.Jun.2015 06.Oct.2015 001 002 16.Dec.2015 003 Changes New Release P16 Correct error in writing P13 start up with output pre-bias voltage P15 Output Capacitor maximum value www.rohm.com © 2015 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 26/26 P14 Restriction of output Bias application TSZ02201-0Q3Q0AJ00480-1-2 16.Dec.2015 Rev.003 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 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 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 © 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 © 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 © 2016 ROHM Co., Ltd. All rights reserved. Rev.001