1-1-3 DC/DC Converter ICs SI-8205NHD Full-Mold, Surface-Mount, Separate CurrentExcitation Mode Control, Step-down Synchronous Switching RectifierMode Step-down Regulator Switching ICs Mode ■Features • • • • • • • • • • ■Absolute Maximum Ratings Compact surface-mount (HSOP8) package Wide input voltage range (VIN): Vo + 3 to 43 V Synchronous rectifier mode Output current: 3 A Reference voltage and accuracy of 0.5 V ±1% Oscillation frequency: 200 kHz to 1 MHz A ceramic capacitor can be used for output Output can be disabled Symbol Ratings Unit VIN PD Tj Tstg θj-c θj-a 46 1.35 –40 to +150 –40 to +150 40 74 V W °C °C °C/W °C/W Soft start function Power supply for LCD module Power supply for notebook PC Conditions When mounted on a 30 × 30 mm glass-epoxy board (with a 25 × 25 mm copper area) When mounted on a 30 × 30 mm glass-epoxy board (with a 25 × 25 mm copper area) ■Recommended Operating Conditions Parameter Undervoltage Lock Out ■Applications • • • • Parameter Input Voltage (VIN Pin) Power Dissipation Junction Temperature Storage Temperature Thermal Resistance (Junction to Lead <1 pin>) Thermal Resistance (Junction to Ambient Air) Input Voltage Range Output Current Range Output Voltage Range Operating Junction Temperature Range Operating Temperature Range Symbol VIN Io Vo Tjop Top Ratings 8 or Vo+3 to 43 0 to 3.0 0.5 to 24 –40 to +125 –40 to +85 Unit V A V °C °C *: The minimum value of the input voltage range is 8 V or Vo + 3V, whichever is higher. Onboard local power supplies Power supply for LBP/PPC ■Electrical Characteristics Parameter Reference Voltage Temperature Coefficient of Reference Voltage Efficiency Oscillation Frequency 1 Oscillation Frequency 2 Line Regulation Load Regulation Overcurrent Protection Starting Current Quiescent Circuit Current Outflow Current at Low Voltage EN/SS Pin Open Voltage On Threshold Voltage OVP Start Voltage Thermal Protection Start Temperature Error Amplifier Voltage Gain Error Amplifier Transformer Conductance Current Sense Amplifier Impedance Maximum ON Duty Minimum ON Time 50 ICs (Ta = 25°C and fo = 500kHz, unless otherwise specified) Symbol Vref ∆VREF/∆T min. 0.495 η fo1 fo2 ∆VoLINE ∆VoLOAD Is IIN IIN(OFF) IEN/SS VSSH VC/EH Vovp Tj AEA GEA GCS DMAX DMIN Ratings typ. 0.500 ±0.05 90 200 1 50 50 3.1 max. 0.505 6.0 8 40 3.0 0.6 0.57 151 80 5 4.5 1.3 0.60 160 800 800 3.33 90 150 Unit V mV/°C % kHz MHz mV mV A mA µA µA 6.0 2.0 0.63 V V V Conditions VIN=12V, Io=1.0A VIN=12V, Io=1.0A, Ta=–40 to +85°C VIN=12V, Vo=5V, Io=1.0A VIN=12V, Vo=5V, Io=1A, Rfset=375kΩ VIN=12V, Vo=5V, Io=1A, Rfset=75kΩ VIN=8 to 43V, Vo to 5V, Io=1A VIN=12V, Vo=5V, Io=0.1 to 3.0A VIN=12V, Vo=5V VIN=12V, Vcomp=0V VIN=12V, VEN/ss=0V VEN/SS=0V, VIN=12V VIN=12V VIN=12V °C V/V µA/V A/V % nsec VIN=12V VIN=12V SI-8205NHD ■External Dimensions (HSOP8) Pin Assignment q GND w EN/SS e VIN r FSET t COMP y FB u BS i SW 0.08±0.08 6.20 4.40 Pin 1 Mark 0.05±0.05 (Unit : mm) Enlarged View of A 1.50 0.695 TYP 5.20 0.15 A 0.4 1.27 0.40 2.70 Plastic Mold Package Type Flammability : UL 94V-0 Product Mass : Approx. 0.1 g 2.90 ■Block Diagram ③VIN + CUR_SUS REG – REG REG_DRV DRV_REG REG REG_DEV REG REG_DEV ⑦BS REG_BIAS STANDBY OVC STANDBY OCP_CMP RegOK REG_UVLO H/S Drv BC VIN_UVLO VinOK M1 Level Shift PWR_stage REG VinOK REG REG VinOK Set PH Fere Off OSC_RAMP Ramp Phase_ logic REG GATE_logic L/S Drv STANDBY LSoft INIT PH INIT CC Res PH CUR_COMP Level Shift LSoft FB FSET④ ⑧SW M2 Phase REG REG VinOK PH Open OVT BS_CHG REG Fere_Off Set PH RegOK VinOK Control_logic OVT TSD BG REG INIT OVP OVP OVP_CMP REG_BIAS REG SS_Ref EN_SS REG BG ⑥FB Ref Err_AMP STANDBY REF Rnf SS_Rnf ①GND ⑤COMP ■Typical Connection Diagram VIN R5 3 VIN 2 EN/SS C1 C4 7 8 BS SW L1 SI-8205NHD 4 C5 FSET GND 1 R4 FB COMP 5 C3 GND C6 Open C2 6 R1 R2 R3 VO D1 GND C1:10µF/50V×2 (murata:GRM55DB31H106KA87) C2:22µF/16V×2 (murata:GRM32ER71A226KE20) C3:270pF (murata:GRM18 type) C4:10µF (murata: GRM18 type) C5:1µF (murata: GRM18 type) L1:10µH D1: SJPB-L6 (Sanken) R1:9kΩ(When Vo=5V) R2:1kΩ R3:51kΩ R4:150kΩ R5:47Ω ICs 51