1/4 STRUCTURE PRODUCTSERIES Silicon Monolithic Integrated Circuit 2-ch Switching Regulator Controller TYPE BD9846FV FEATURES ・High Input-voltage ( Vcc=35V) ・MOSFET-driver circuit built-in（dual circuit for step-down output） ・Built-in circuits for error amplifier reference voltage (ch1:eternal regulation is possible , ch2:1.0 V1%) ・Over current detection circuit built-in. ・Soft-start timing adjustable ○Absolute maximum ratings（Ta=25℃） Item Symbol Limits Unit Vcc 36 V Power dissipation Pd 812＊1 mW Output pin voltage VOUT Vcc-7V～Vcc V C5V pin voltage VC5V Vcc-7V～Vcc V Operating temperature Topr -40～+105 ℃ Storage temperature Tstg -55～+150 ℃ Tjmax 150 ℃ Power Supply Voltage Maximum Junction temperature *1 Should be deleted by 6.5mW/℃ at Ta=25℃ or more. When mounted on a glass epoxy PCB of 70.0mm×70.0 mm×1.6 mm ○Recommended operating range (Ta=25℃) Item Power Supply Voltage Symbol Min. Typ. Max. Unit Vcc 3.6 6.0 35 V VOUT C5V - Vcc V VERRIN 0 - 1.6 V CCT 47 - 3000 pF Oscillation frequency fosc 100 - 1500 kHz STB input voltage VSTB 0 - VCC V Output pin voltage Error amplifier input voltage Timing capacitor ○Electrical characteristics (Unless otherwise specified, Ta=25℃，VCC=6V) Limits Item Symbol Unit Max Min. Typ. . 【VREF output block】 2.47 2.50 2.52 VREF output voltage VREF V 5 0 5 Line regulation Line reg. ― 1 10 mV Load regulation Output max. current Conditions IO=0.1mA Vcc=3.6V→35V Load reg. ― 2 10 mV IO=0.1mA→2mA IOMAX 2 13 ― mA VREF=(typ.)＊0.95 REV. A 2/4 ○Electrical characteristics (Unless otherwise specified, Ta=25℃，VCC=6V) Item Symbol Min. limits Typ. Max. Unit Conditions 【Triangular wave oscillator block】 Oscillation frequency fOSC 95 106 117 kHz Frequency variation fDV ― 0 1 % SS pin source current ISSSO 1.4 2 2.6 μA SS=0.5V SS pin sink current ISSSI 5 12 ― mA SS=0.5V IDT ― 0.1 1 μA DT=1.75V IDTSI 1 3.3 ― mA DT=1.75V, (OCP+)-(OCP-)=0.5V Threshold voltage VUTH 3.0 3.2 3.4 V Hysterisis VUHYS ― 0.15 0.25 V Inon － 0 1 μA NON=1V Non-Inverting input reference voltage(ch2) VINV 0.99 1 1.01 V INV=FB Reference voltage variation (ch2) dVinv － 1 6 mV Vcc=3.6V→35V IIB ― 0 1 μA INV=1V CCP=1800pF Vcc=3.6V→35V 【Soft-start block】 【Dead time adjustable circuit block】 DT pin input bias current DT pin sink current 【UVLO block】 Vcc when rise time 【Error Amp block】 NON input bias current (ch1) INV input bias current AV 70 85 ― dB Output FB voltage (Hi) VFBH 2.30 ― VREF V Output FB voltage (Low) VFBL － 0.6 1.3 V Output sink current IFBSI 0.5 1.5 － mA FB=1.25V , INV=1.5V Output source current IFBSO 50 105 － μA FB=1.25V , INV=0V Vt0 1.4 1.5 1.6 V On duty 0% Vt100 1.9 2 2.1 V On duty 100% RONH － 4 10 Ω RONH=( VCC -OUT)/ Iout, Iout=0.1A Open loop gain 【PWM comparator】 Input threshold voltage （fosc=100kHz） 【Output block】 Output ON resistance H Output ON resistance L RONL － 3.3 10 Ω RONL=(OUT-C5V)/ Iout, Iout=0.1A C5V clamp voltage VCLMP 4.5 5 5.5 V VCLMP= VCC-C5V , VCC ＞7V VOCPTH 0.04 0.05 0.06 V Voltage between (OCP+)-(OCP-) 【Over current protection circuit (OCP) block】 OCP threshold voltage IOCP- － 0.1 10 μA OCP+= VCC, OCP-= VCC-0.05V Delay time for OCP tdocpth ― 200 400 nS OCP-= VCC→VCC-0.2V Min. hold time for OCP tdocpre 0.8 1.6 ― mS OCP-= VCC-0.2V→VCC Threshold voltage for each CH stop VDTthL 1.1 1.25 1.4 V Stand-by mode setting voltage range VSTBL 0 － 0.5 V Active setting voltage range VSTBH 3 － VCC V ISTB ― 70 100 μA STB=6V Stand-by current ICCS ― 0 1 μA STB=0V Average current consumption ICCA 1.5 3 6 mA INV=0V, FB=H, DT=1.75V OCP-input bias current 【Stand-by switch block】 STB current DT Pin H/L 【Total device】 ※Not designed for radiation resistance. REV. A 3/4 ○Outline figure ○PIN No./ name / function Pin No. 1 DT2 Dead time setting (CH2) SS2 Soft-start time setting (CH2) 4 INV2 Error Amp inverting input (CH2) 5 FB2 Error Amp output (CH2) 6 GND GROUND 7 OCP2－ Over current error amp inverting input (CH2) 8 OCP2＋ Over current error amp input (CH2) 9 C5V 10 OUT2 CH2 Output 11 OUT1 CH1 Output Lot NO. ○Block Diagram Output L voltage（Vcc-5V） 12 Vcc 13 OCP1＋ 14 OCP1－ 15 STB Stand-by mode control 16 FB1 Error Amp output (CH1) 17 INV1 Error Amp inverting input (CH1) 18 SS1 Soft-start time setting (CH1) 19 NON1 Error Amp input (CH1) 20 VREF Reference voltage（2.5V）output STB VCC External Capacitor pin for timing change 3 BD9846 SSOP-B20 (Unit : mm) CT Pin function 2 type 1 pin Mark Pin name Power supply input Over current error amp input (CH1) Over current error amp inverting input (CH1) OCP1+ OCP1- VCC VCC VREF VCC STB REG (2.5V) VREF + OCP1 OCP VREF C5V - REG (VCC-5V) 50mV±10mV C5V C5V FB1 DT1OFF NON1 DT + DT1Low 1.25V VREF 2μA SS1 SS1OFF VCC + + PWM - + + ERR - LS DRV OUT1 C5V INV1 PROTECTION LOGIC OSC DT1Low SS1OFF 200μA + 200μA OCP1 1.5V TSD DT1OFF Hold time (1.6msec) 2.0V TSD UVLO TSD VCC Hold time (0.2msec) VREF 2V 1.5V OCP2 DT2OFF Hold time (1.6msec) CT C5V 3.2V 2.2V UVLO SS2OFF DT2Low INV2 VCC VREF 2μA SS2 SS2OFF + ERR + + PWM + LS VCC FB2 DT2OFF DT + DT2Low OUT2 DRV 1V±10mV DT2 UVLO 3V OCP2 50mV±10mV - C5V OCP + C5V 1.25V REV. A OCP2+ OCP2- GND 4/4 ○Operation Notes 1) Absolute maximum ratings Use of the IC in excess of absolute maximum ratings such as the applied voltage or operating temperature range may result in IC deterioration or damage. Assumptions should not be made regarding the state of the IC (short mode or open mode) when such damage is suffered. A physical safety measure such as a fuse should be implemented when use of the IC in a special mode where the absolute maximum ratings may be exceeded is anticipated. 2) GND potential Ensure a minimum GND pin potential in all operating conditions. In addition, ensure that no pins other than the GND pin carry a voltage lower than or equal to the GND pin, including during actual transient phenomena. 3) Thermal design Use a thermal design that allows for a sufficient margin in light of the power dissipation (Pd) in actual operating conditions. 4) Inter-pin shorts and mounting errors Use caution when orienting and positioning the IC for mounting on printed circuit boards. Improper mounting may result in damage to the IC. Shorts between output pins or between output pins and the power supply and GND pin caused by the presence of a foreign object may result in damage to the IC. 5) Operation in a strong electromagnetic field Use caution when using the IC in the presence of a strong electromagnetic field as doing so may cause the IC to malfunction. 6) Thermal shutdown circuit (TSD circuit) This IC incorporates a built-in thermal shutdown circuit (TSD circuit). The TSD circuit is designed only to shut the IC off to prevent runaway thermal operation. Do not continue to use the IC after operating this circuit or use the IC in an environment where the operation of the thermal shutdown circuit is assumed. 7) Testing on application boards When testing the IC on an application board, connecting a capacitor to a pin with low impedance subjects the IC to stress. Always discharge capacitors after each process or step. Ground the IC during assembly steps as an antistatic measure, and use similar caution when transporting or storing the IC. Always turn the IC's power supply off before connecting it to or removing it from a jig or fixture during the inspection process. 8) Common impedance Power supply and ground wiring should reflect consideration of the need to lower common impedance and minimize ripple as much as possible (by making wiring as short and thick as possible or rejecting ripple by incorporating inductance and capacitance). 9) Applications with modes that reverse VCC and pin potentials may cause damage to internal IC circuits. For example, such damage might occur when VCC is shorted with the GND pin while an external capacitor is charged. It is recommended to insert a diode for preventing back current flow in series with VCC or bypass diodes between VCC and each pin. 10) IC pin input This monolithic IC contains P+ isolation and PCB layers between adjacent elements in order to keep them isolated. P/N junctions are formed at the intersection of these P layers with the N layers of other elements to create a variety of parasitic elements. For example, when a resistor and transistor are connected to pins as shown in Fig. 10, The P/N junction functions as a parasitic diode when GND > (Pin A) for the resistor or GND > (Pin B) for the transistor (NPN). Similarly, when GND > (Pin B) for the transistor (NPN), the parasitic diode described above combines with the N layer of other adjacent elements to operate as a parasitic NPN transistor. The formation of parasitic elements as a result of the relationships of the potentials of different pins is an inevitable result of the IC's architecture. The operation of parasitic elements can cause interference with circuit operation as well as IC malfunction and damage. For these reasons, it is necessary to use caution so that the IC is not used in a way that will trigger the operation of parasitic elements, such as by the application of voltages lower than the GND (PCB) voltage to input and output pins. Resistance Bypass diode Transistor (NPN) (PinA) (PinA) Ｂ (PinB) Ｅ Ｃ Parasitic diode Back current prevention diode Ｎ Ｐ VCC Ｎ Ｐ ＋ Ｐ Ｎ Ｐ ＋ Ｎ Ｎ ＧＮＤ Parasitic diode ＧＮＤ Ｐ Ｐ Ｎ ＧＮＤ (PinB) ＋ Ｎ P substrate P substrate Output Pin ＋ Ｂ Ｃ Ｅ ＧＮＤ Parasitic elements Other adiacent components REV. A ＧＮＤ Parasitic diode Notice Notes No copying or reproduction of this document, in part or in whole, is permitted without the consent of ROHM Co.,Ltd. The content specified herein is subject to change for improvement without notice. The content specified herein is for the purpose of introducing ROHM's products (hereinafter "Products"). If you wish to use any such Product, please be sure to refer to the specifications, which can be obtained from ROHM upon request. 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