1-1-3 DC/DC Converter ICs SI-8000FFE Series Full-Mold, Separate Excitation Step-down Switching Mode ■Features ■Lineup • Compact full-mold package (equivalent to TO220) • Output current: 3.5 A Part Number SI-8001FFE Variable (0.8 to 24) Vo (V) Io (A) 3.5 Function Soft start • High efficiency: 83% (Vo = 5 V, VIN = 15 V, Io = 2 A) • Requires only 6 discrete components • Built-in reference oscillator (300 kHz) • Built-in drooping-type overcurrent and thermal protection circuits • Built-in soft start circuit (Output ON/OFF available) ■Applications ■Absolute Maximum Ratings Parameter Input Voltage Symbol Ratings VIN 43 Power Dissipation PD1-1 22.7 (With infinite heatsink) PD1-2 18.2 Power Dissipation PD2-1 2.15 (Without heatsink) PD2-2 1.72 Tj +150 Junction Temperature*1 Unit SI-8001FFE V Limited by thermal protection circuit, Tj=150°C W Tj=125°C Limited by thermal protection circuit, Tjmax=150°C W Tj=125°C °C • DVD recorder, FPD-TV Storage Temperature Tstg –40 to +150 °C • OA equipment, such as printers Thermal Resistance (Junction to Case) θj-c 5.5 °C/W Thermal Resistance (Junction to Ambient Air) θj-a 58 °C/W • Onboard local power supplies Conditions *: This product has built-in thermal protection circuits that may activate when the junction temperature exceeds 130°C. The recommended design for the junction temperature during IC operation is below 125°C. ■Recommended Operating Conditions Parameter Ratings Symbol Unit SI-8001FFE Vo+3*1 Input Voltage Range VIN Output Voltage Range VO 0.8 to 24 to 40 V Output Current Range IO 0 to 3.5 A Operating Junction Temperature Range Tjop –30 to +125 °C Operating Temperature Range Top –30 to +85 °C V *: The minimum value of the input voltage range is 4.5 V or Vo +3 V, whichever is higher. ■Electrical Characteristics (R1=4.2kΩ, R2=0.8kΩ when Ta=25°C and Vo=5V) Ratings Parameter Symbol SI-8001FFE min. VADJ Reference Voltage 0.784 Conditions Temperature Coefficient of Reference Voltage Oscillation Frequency ∆VADJ/∆T VIN=15V, Io=0.2A, Tc=0 to 100°C Conditions VIN=15V, Io=2A fo 270 Outflow Current at Low Voltage IS kHz 80 mV VIN=10 to 30V, Io=2A 15 50 mV VIN=15V, Io=0.2 to 3.5A 3.6 Conditions A VIN=15V VSSL 0.5 ISSL 6 Conditions VIN=15V, VSS=0V Conditions VIN=15V, Io=0A V 30 µA 6 Iq(OFF) *: Pin 5 is the SS pin. Soft start at power on can be performed with a capacitor connected to this pin. The output can also be turned ON/OFF with this pin. The output is stopped by setting the voltage of this pin to VSSL or lower. SS-pin voltage can be changed with an open-collector drive circuit of a transistor. When using both the soft-start and ON/OFF functions together, the discharge current from C3 flows into the ON/ OFF control transistor. Therefore, limit the current securely to protect the transistor if C3 capacitance is large. The SS pin is pulled up (3.7 V typ.) to the power supply in the IC, so applying the external voltage is prohibited. If this pin is not used, leave it open. mA 200 600 µA VIN=15V, Vss=0V SI-8000FFE 5 SS SI-8000FFE 5 SS C3 VO.ON/OFF ICs 330 55 Conditions 50 % VIN=15V, Io=2A Iq Quiescent Circuit Current mV/ °C 300 Conditions Conditions Low Level Voltage SS Pin V 83 ∆VOLOAD Overcurrent Protection Starting Current 0.816 Conditions Conditions Load Regulation 0.800 ±0.1 ∆VOLINE Line Regulation max. VIN=15V, Io=0.2A η Efficiency Unit typ. Soft start SI-8000FFE 5 SS C3 Soft start +Vo. ON/OFF SI-8000FFE Series ■External Dimensions (TO220F-5) (Unit : mm) ±0.2 4.2 ±0.2 2.8 ±0.2 4.0±0.2 7.9±0.2 φ 3.2±0.2 0.5 16.9±0.3 Pin Assignment (2.0) 2.6±0.1 q IN w SW e GND r ADJ t SS (17.9) 10.0 Plastic Mold Package Type 0.95±0.15 Flammability: UL 94V-0 4.6±0.6 (4.6) +0.2 0.85 –0.1 Product Mass: Approx. 2.3 g +0.2 P1.7±0.7×4=6.8±0.7 0.45 –0.1 3.9±0.7 (4.3) 8.2±0.7 1 2 3 4 5 ■Block Diagram 1 SW IN PReg. 2 OCP 5 SS ON/OFF Soft start Latch & Drive Reset OSC + – ADJ TSD Comp. Error Amp. 4 – + + VREF GND 3 ■Typical Connection Diagram L1 1 VIN SW IN SI-8001FFE + C1 SS 5 GND 3 2 VOUT R1 ADJ 4 + C2 R2 Di IADJ C3 GND GND C1 C2 C3 L1 D1 :470µF :680µF :0.1µF(Only when using soft-start function) :47µH :RK46(Sanken) ICs 51