TECHNICAL NOTE Large Current External FET Controller Type Switching Regulators High temperature ESD operating Resistance Single-output High-frequency Step-down Now available Now available Switching Regulator(Controller type) BD9850FVM Dual-output Step-up, Negative, Step-down Switching Regulator(Controller type) BD9851EFV Description The BD9850FVM is a 1-channel DC/DC step-down switching regulator controller, while the BD9851EFV is a 2-channel DC/DC step-down switching regulator controller. The BD9850FVM is adaptable for a maximum switching frequency of 2 MHz and the BD9851EFV for that of 3 MHz. Both provide space saving in all applications. Features 1) Adaptable for 2-MHz switching frequency (externally variable) (BD9850FVM) Adaptable for 3-MHz switching frequency (externally variable) (BD9851EFV) 2) FET direct drive 3) High-accuracy reference voltage (Accuracy: 1%) 4) Built-in Under Voltage Lock Out circuit (UVLO) 5) Built-in Thermal Shutdown circuit (TSD) 6) The BD9851EFV provides two channels: Channel 1 available for selection of step-down/step-up switching Channel 2 available for selection of step-down/inverting switching. 7) Compact MSOP8 package (BD9850FVM) / HTSSOP-B20 package (BD9851EFV) Applications TFT panel, TA/Router, digital consumer electronics, PC, and portable CD/DVD/DVC Product lineup BD9850FVM BD9851EFV Input range 4V to 9V 4V to 18V Oscillation frequency range 100kHz to 2MHz 10kHz to 3MHz External synchronization Not provided Not provided Standby function Not provided Provided Operating temperature 40C to 85C 40C to 85C Package MSOP8 HTSSOP-B20 Sep. 2008 ROHM CO., LTD .Absolute maximum ratings (Ta=25C) BD9850FVM Item Symbol Rating Unit Power supply voltage Vcc 10 V Storage temperature Tstg 55 to +150 C Operating temperature Topr 40 to +85 C * Power dissipation Pd 587 mW Maximum junction temperature Tjmax +150 C Reduce by 4.7 mW/C over 25C (When mounted on PCB of 70mm70mm1.6mm) * BD9851EFV Item Symbol Rating Unit Power supply voltage Vcc 20 V (Between Vcc and GND) VREF 7 V Between VREF and GND Between OUT1 and PVcc1 Vouth 20 V Between OUT2 and PVcc2 Between OUT1, OUT2 and PGND Voutl 20 V ( ) * Power dissipation Pd 1000 mW Operating temperature Topr 40 to +85 C Maximum junction temperature Tjmax +150 C Storage temperature Tstg 55 to +150 C ( )Reduce by 8.0 mW/C over 25C (When mounted on PCB of 70mm70mm1.6mm) * Recommended operating range BD9850FVM Limits Item Symbol Unit min. Typ. max. Power supply voltage Vcc 4 7 9 V Oscillation frequency fosc 100 2000 kHz Operating temperature Topr 40 +85 C BD9851EFV Limits Item Symbol Unit min. Typ. max. Power supply voltage Vcc 4 12 18 V Oscillation frequency fosc 10 300 3000 kHz Timing resistor RRT 3.3 47 k CCT Timing capacitor 33 10000 pF 2/16
