1-1-3 DC/DC Converter ICs SI-8000TM Series Surface-Mount, Separate Excitation Step-down Switching Mode ■Features ■Absolute Maximum Ratings • Compact surface-mount package (TO252-5) Parameter Symbol Ratings Unit VIN 43 V PD1 1.06 PD2 1.65 Junction Temperature* Tj –30 to +150 Storage Temperature Tstg –40 to +150 °C Thermal Resistance (Junction to Case) θ j-c 6 °C/W Thermal Resistance (Junction to Ambient Air) θ j-a 95 °C/W • Output current: 1.5 A DC Input Voltage • High efficiency: 81% typ. (at Vo = 5 V) Power Dissipation • Requires only 4 discrete components • Built-in reference oscillator (300 kHz) • Built-in drooping-type-overcurrent and thermal protection circuits W Conditions When mounted on glass-epoxy board (900 mm2 copper area 4.3%) When mounted on glass-epoxy board (900 mm2 copper area 50%) °C When mounted on glass-epoxy board (900 mm2 copper area 4.3%) *: This product has built-in thermal protection circuits that may operate when the junction temperature rises above 130°C. The recommended design for the junction temperature during operation is below 125°C. • Output ON/OFF available (circuit current at output OFF: 200 µA typ.) • Soft start available by ON/OFF pin ■Applications • Onboard local power supplies • AV equipment • OA equipment ■Recommended Operating Conditions Ratings Parameter Symbol Unit SI-8008TM Input Voltage Range VIN VO+3*1 to 40 V Output Voltage VO 0.8 to 24 V Output Current Range IO 0 to 1.5 A Operating Junction Temperature Range Tjop –20 to +100 °C Operating Temperature Range Top –20 to +85 °C *1: The minimum value of an input voltage range is the higher of 4.5 V or VO + 3 V. ■Electrical Characteristics (Ta=25°C) Rating Parameter Reference Voltage Temperature Coefficient of Reference Voltage Symbol min. 0.784 VADJ Conditions ∆VADJ/∆T Conditions η Efficiency Conditions Oscillation Frequency fo 300 VIN=15V, Io=0.5A 60 VIN=10 to 30V, Io=0.5A 10 VIN=15V, Io=0.2 to 1.5A Conditions ∆VOLINE Line Regulation Conditions ∆VOLOAD Load Regulation Conditions Overcurrent Protection Starting Current IS SI-8008TM typ. 0.800 VIN=15V, Io=0.1A ±0.1 VIN=15V, Io=0.1A, Tc=0 to 100°C 81 VIN=15V, Io=0.5A Outflow Current at Low Voltage ISSL Conditions Conditions 6 VIN=15V, Io=0A Conditions 200 VIN=15V, VSS=0V 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 to the power supply in the IC, so applying the external voltage is prohibited. If the pin is not used, leave it open. kHz mV 40 mV A 0.5 40 V µA mA 400 SI-8000TM 5 SS VO. ON/OFF ICs % VIN=15V 10 VSSL=0V Iq 18 mV/°C 1.6 Conditions Quiescent Circuit Current V 80 Low Level Voltage VSSL ON/OFF Pin* Unit max. 0.816 µA SI-8000TM 5 SS SI-8000TM 5 SS C3 C3 Soft start Soft start +VO. ON/OFF SI-8000TM Series ■External Dimensions (TO252-5) (Unit : mm) 6.60±0.20 2.30 ±0.20 5.34 ±0.20 (5.04) 0.50±0.10 (1.50) 5 1.10 ±0.20 6.60 5.34±0.20 ±0.20 (4.06) 9.90 0.1 Plastic Mold Package Type Flammability: UL94V-0 Product Mass: Approx. 0.33 g 8° 0 to 0.50±0.10 0.50±0.10 1.27 TYP 2.70±0.20 1.18±0.20 (0.89) 2.70±0.20 9.90 SEATING PLANE 0.00 to 0.127 ±0.30 R0 ±0.30 6.10±0.20 .3 2 Pin Assignment q IN w SW e GND r ADJ t SS (1.00) 1.27 TYP 2.30±0.20 1 2 3 4 5 ■Block Diagram ■Typical Connection Diagram L1 L47µH SW IN 5 SS ON/OFF Soft Start 2 Overcurrent Protection PReg. SW IN SI-8000TM C1 220µF Latch & Drive Reset + SS 5 GND 3 2 VO R1 ADJ 4 + R2 Di C2 470µF IADJ C3 OSC + – Thermal Protection Comp. Error Amp. + + – 1 1 VIN SI-8008TM Reference Voltage GND 3 GND GND ADJ 4 C1 C2 C3 L1 Di : 220µF : 470µF : 1µF (Only when using soft-start function) : 47µF : SJPB-H6 (Sanken) ICs 19