BD9778F-E2 ROHM

Rcaflga j LmrcRRcaR f lga j L Single-chip Type with built-in FET Switching Regulator Series Flexible Step-down Switching Regulators with Built-in Power MOSFET No.10027EBT41 BD9778F, BD9778HFP, BD9001F, BD9781HFP Overview The flexible step-down switching regulator controller is a switching regulator controller designed with a high-withstand-voltage built-in POWER MOS FET, providing a free setting function of operating frequency with external resistor. This switching regulator controller features a wide input voltage range (7 V to 35 V or 7 V to 48 V) and operating temperature range (-40C to +125C or -40C to +95C). Furthermore, an external synchronization input pin (BD9781HFP) enables synchronous operation with external clock. Features 1) Minimal external components 2) Wide input voltage range: 7 V to 35 V (BD9778F/HFP and BD9781HFP), 7 V to 48 V (BD9001F) 3) Built-in P-ch POWER MOS FET 4) Output voltage setting enabled with external resistor: 1 to VIN 5) Reference voltage accuracy: 2% 6) Wide operating temperature range: -40C to +125C (BD9778F/HFP and BD9781HFP), -40C to +95C (BD9001F) 8) Low dropout: 100% ON Duty cycle 9) Standby mode supply current: 0 A (Typ.) (BD9778F/HFP and BD9781HFP), 4 A (Typ.) (BD9001F) 10) Oscillation frequency variable with external resistor: 50 to 300 kHz (BD9001F), 50 to 500 kHz (BD9778F/HFP and BD9781HFP) 11) External synchronization enabled (only on the BD9781HFP) 12) Soft start function : soft start time fixed to 5 ms (Typ.)) 13) Built-in overcurrent protection circuit 14) Built-in thermal shutdown protection circuit 15) High power HRP7 package mounted (BD9778HFP and BD9781HFP) Compact SOP8 package mounted (BD9778F and BD9001F) Applications All fields of industrial equipment, such as Flat TV , printer, DVD, car audio, car navigation, and communication such as ETC, AV, and OA. Product lineup Item BD9778F/HFP BD9001F BD9781HFP Output current 2A 2A 4A Input range 7V ~ 35V 7V ~ 48V 7V ~ 35V Oscillation frequency range 50 ~ 500kHz 50 ~ 300kHz 50 ~ 500kHz External synchronization Not provided Not provided Provided Standby function Provided Provided Provided Operating temperature -40C ~ +125C -40C ~ +95C -40C ~ +125C Package SOP8 / HRP7 SOP8 HRP7 www.rohm.com 1/16 2010 ROHM Co., Ltd. All rights reserved.BD9778F, BD9778HFP, BD9001F, BD9781HFP Technical Note Absolute Maximum Ratings(Ta = 25C) Parameter Symbol Limits Unit BD9778F/HFP,BD9781HFP 36 Power supply VIN V BD9001F voltage 50 Output switch pin voltage VSW VIN V *1 BD9778F/HFP, BD9001F 2 Output switch current ISW *1 A BD9781HFP 4 VEN/SYNC,VEN VIN EN/SYNC, EN pin voltage V RT, FB, INV pin voltage 7 VRT,VFB,VINV *2 HRP7 5.5 Power dissipation Pd W *3 SOP8 0.69 Operating temperature BD9778F/HFP,BD9781HFP -40 ~ +125 Topr C range BD9001F -40 ~ +95 Tstg -55 ~ +150 C Storage temperature range Maximum junction temperature Tjmax 150 C *1 Should not exceed Pd-value. *2 Reduce by 44mW/C over 25C, when mounted on 2-layer PCB of 70 X 70 X 1.6 mm3. (PCB incorporates thermal via. Copper foil area on the front side of PCB: 10.5 X 10.5 mm2. Copper foil area on the reverse side of PCB: 70 X 70 mm2) *3 Reduce by 5.52 mW/C over 25C, when mounted on 2-layer PCB of 70 X 70 X 1.6 mm3. Recommended operating range Parameter BD9778F/HFP BD9001F BD9781HFP Unit Operating power supply voltage 7 ~ 35 7 ~ 48 7 ~ 35 V Output switch current A ~ 2 ~ 2 ~ 4 Output voltage (ON Duty) % 6 ~ 100 6 ~ 100 6 ~ 100 Oscillation frequency kHz 50 ~ 500 50 ~ 300 50 ~ 500 k Oscillation frequency set resistance 40 ~ 800 100 ~ 800 39 ~ 800 Possible operating range Parameter BD9778F/HFP BD9001F BD9781HFP Unit Operating power supply voltage 5 ~ 35 7 ~ 48 5 ~ 35 V Electrical characteristics BD9778F/HFP (Unless otherwise specified, Ta = -40C to +125C, VIN =13.2 V, VEN = 5 V) Limits Parameter Symbol Unit Condition Min. Typ. Max. Standby circuit current ISTB - 0 10 A VEN=0V,Ta=25C Circuit current IQ - 3 4.2 mA IO=0A SW block RON - 0.53 0.9 ISW=50mA POWER MOS FET ON resistance Operating output current of overcurrent protection IOLIMIT 2 4 - A * Design assurance Output leak current IOLEAK - 0 30 A VIN=35V,VEN=0V Error Amp block Reference voltage 1 VREF1 0.98 1.00 1.02 V VFB=VINV,Ta=25C Reference voltage 2 VREF2 0.96 1.00 1.04 V VFB=VINV Reference voltage input regulation V REF - 0.5 - % VIN=5 ~ 35V Input bias current IB -1 - - A VINV=1.1V Maximum FB voltage VFBH 2.4 2.5 - V VINV=0.5V Minimum FB voltage VFBL - 0.05 0.10 V VINV=1.5V FB sink current IFBSINK -5.0 -3.0 -0.5 mA VFB=1.5V,VINV=1.5V FB source current IFBSOURCE 70 120 170 A VFB=1.5V,VINV=0.5V Soft start time TSS - 5 - mS * Design assurance Oscillator block Oscillation frequency FOSC 82 102 122 kHz RT=390k Frequency input regulation F OSC - 1 - % VIN=5 ~ 35V Enable block VEN 0.8 1.7 2.6 V Threshold voltage IEN - 13 50 A VEN=5V Sink current * Not designed to be radiation-resistant. www.rohm.com 2/16 2010 ROHM Co., Ltd. All rights reserved.