1-1-3 DC/DC Converter ICs SI-8100QL Series Current Mode Control Step-down Switching Mode ■Features ■Absolute Maximum Ratings • DIP8 package Symbol Ratings Unit • Introduction of current mode control method Input Voltage Parameter VIN 30 V • Output current: 3.5A Power Dissipation*1 PD 1.56 W Junction Temperature*2 Tj –30 to +150 °C Storage Temperature Tstg –40 to +150 °C Thermal Resistance (Junction to Case) θj-c 25 °C/W Thermal Resistance (Junction to Ambient Air) θj-a 64 °C/W • High efficiency: 90% (Vo=5V) • Built-in reference oscillator (350kHz) • Built-in drooping-type overcurrent and thermal protection circuits • Built-in soft start circuit Conditions When mounted on glass-epoxy board measuring 70×60 mm (copper laminate area: 1310 mm2) When mounted on glass-epoxy board measuring 70×60 mm (copper laminate area: 1310 mm2) *1: Limited by thermal protection circuit *2: Note that the detect temperature for thermal protection is about 140°C. • Built-in on/off function (Active Hi) • Low current consumption during off ■Recommended Operating Conditions Parameter ■Applications Symbol Ratings Unit SI-8105QL Vo+3*1 Input Voltage Range VIN Output Voltage Range Vo 0.5 to 24 • Onboard local power supplies Output Current Range Io 0 to 3.5 A • OA equipment Operating Junction Temperature Range Tjop –30 to +125 °C Operating Temperature Range Top –30 to +85 °C • DVD recorder, FPD-TV to 28 Conditions V V *1: The minimum value of the input voltage range is 4.75 V or Vo +3 V, whichever is higher. ■Electrical Characteristics (When Ta=25°C and Vo=5V) Ratings Parameter Symbol SI-8105QL min. VADJ Reference Voltage 0.485 Conditions Temperature Coefficient of Reference Voltage Oscillation Frequency (∆VADJ/∆T) VIN=12V, Io=1A, Ta=–40 to +85°C Conditions VIN=12V, Io=1A fo 315 Conditions 30 30 Outflow Current at Low Voltage High Level Voltage EN Pin Low Level Voltage Inflow Current at Low Voltage 60 60 VIN=12V, Io=0.1 to 3.5A 3.6 6.0 Conditions VIN=12V Conditions VIN=12V, Io=0A, VEN=open 18 Iq(OFF) SS Pin 385 VIN=8 to 28V, Io=1A Iq Quiescent Circuit Current % VIN=16V, Io=1A Conditions Is 350 VIN=12V, Io=0A, VEN=0V Conditions VIN=12V, VSSL=0V ISSL 5 VC/EH VIN=12V Conditions VIN=12V Conditions VEN=0V VC/EL 5 mV A µA V 2.2 IC/EH mV µA 2.8 Conditions kHz mA 20 Conditions V mV/ °C 90 ∆VoLOAD Overcurrent Protection Starting Current 0.515 Conditions Conditions Load Regulation 0.500 0.05 ∆VoLINE Line Regulation max. VIN=12V, Io=1A η Efficiency Unit typ. V µA Error Amplifier Voltage Gain AEA 1000 V/V Error Amplifier Transformer Conductance GEA 800 µA/V Current Sense Amplifier Impedance 1/GCS 0.35 V/A Maximum ON Duty DMAX 92 % Minimum ON Time DMIN 100 nsec. *: Pin 8 is the SS pin. Soft start at power on can be performed with a capacitor connected to this pin. The SS pin is pulled up to the power supply in the IC, so applying the external voltage is prohibited. SI-8100QL 8 SS C5 Soft start 48 ICs SI-8100QL Series ■External Dimensions (DIP8) 7 6 5 6.5±0.2 8 (Unit : mm) 2 3 4 4.2±0.3 3.4±0.1 9.4±0.3 1.0+0.3 -0.05 7.5±0.5 1 Pin Assignment 1 BS 2 IN 3 SW 4 GND 5 FB 6 COMP 7 EN 8 SS 7.6 1.5+0.3 -0.05 +0.1 0.25-0. 05 3.3±0.2 Plastic Mold Package Type Flammability: UL 94V-0 Product Mass: Approx. 0.49 g 0.5±0.1 2.54 0.25 M 0° to 15° 0.89 TYP ■Block Diagram 2 IN Current Sense Amp OSC P.REG Boot REG OCP 5v_ldo 1 BS VREF 0.5V ON OFF 7 EN PWM LOGIC Drive 3 SW OVP TSD 5v_ldo 6 COMP 5 FB Amp UVLO 0.5V 4 GND 8 SS ■Typical Connection Diagram VIN 7 2 IN 1 BS EN C4 R1 SI-8105QL 8 C1 SS GND COMP 6 C5 C6 OPEN C3 R3 VO L1 SW 3 FB 5 D1 GND VFB C2 R2 IADJ GND C1:10µ F/50V (Murata: GRM55DB31H106KA87) C2:22µ F/16V (Murata: GRM32ER71A226KE20) C3:560pF*1 (Murata: GRM18 Type) C4:10nF (Murata: GRM18 Type) C5:10nF (Murata: GRM18 Type) L1:10µ H D1:SPB-G56S (Sanken) SJPB-L4 (Sanken) R1:46kΩ (When Vo = 5 V) R2:5.1kΩ R3:24kΩ*1 *1: When Vo=5V ICs 49