RS6513

Page No. : 1/7 RS6513 PWM Control 2A Step-Down Converter RS6513 provides low-ripple power, high efficiency, and excellent transient characteristics. The PWM control circuit is able to vary the duty ratio linearly from 0 up to 100%. This converter also contains an error amplifier circuit as well as a soft-start circuit that prevents overshoot at startup. An enable function, an over current protect function and a short circuit protect function are built inside, and when OCP or SCP happens, the operation frequency will be reduced from 350KHz to 30KHz. Also, an internal compensation block is built in to minimum external component count. With the addition of an internal P-channel Power MOS, a coil, capacitors, and a diode connected externally, these ICs can function as step-down switching regulators. They serve as ideal power supply units for portable devices when coupled with the SOP–8L mini-package, providing such outstanding features as low current consumption. Since this converter can accommodate an input voltage up to 18V, it is also suitable for the operation via an AC adapter. Features • Input voltage: 3.6V to 18V. • Output voltage: 0.8V to VCC. • Duty ratio: 0% to 100% PWM control • Oscillation frequency: 350KHz typ. • Soft-start, Current limit, Enable function • Thermal Shutdown function • Built-in internal SW P-channel MOS • SOP-8L Pb-Free Package. .Pin Applications • PC Motherboard • LCD Monitor • Graphic Card • DVD-Video Player • Telecom Equipment • ADSL Modem • Printer and other Peripheral Equipment • Microprocessor core supply • Networking power supply Configurations Pin 1: Feedback pin. Pin 2: Power-off pin H: Normal operation (Step-down operation) L: Step-down operation stopped (All circuits deactivated) Pin 3: Add an external resistor to set max output current Pin 4: IC power supply pin Pin 7: GND Pin Pin 8: GND Pin Pin 5: Switch Pin. Connect external inductor/diode here. Minimize trace area at this pin to reduce EMI Pin 6: Switch Pin. Connect external inductor/diode here. Minimize trace area at this pin to reduce EMI DS-RS6513-03 Oct, 2007 www.Orister.com Page No. : 2/7 Block Diagram Absolute Maximum Ratings Symbol VCC VFB VEN VOUTPUT PD TOPR TSTG Parameter VCC Pin Voltage Feedback Pin Voltage EN Pin Voltage Switch Pin Voltage Power Dissipation Operating Temperature Range Storage Temperature Range Range VSS-0.3 to VSS+22 VSS-0.3 to VCC VSS-0.3 to VIN+0.3 VSS-0.3 to VIN+0.3 Internally limited -20 to +125 -40 to +150 Units V V V V mW o C o C Electrical Characteristics (VIN = 12V, Ta=25°C, unless otherwise specified) Symbol VIN VFB IFB ISW ISSS ΔVOUT/VOUT ΔVOUT/VOUT FOSC FOSC1 VSH VSL ISH ISL IOCSET TSS RDSON EFFI θJA Parameter Input Voltage Feedback Voltage Feedback Bias Current Switch Current Current Consumption During Power Off Line Regulation Load Regulation Oscillation Frequency Frequency of Current Limit or Short Circuit Protect EN Pin Input Voltage EN Pin Input Leakage Current OCSET Pin Bias Current Soft-Start Time Internal MOSFET RDSON Efficiency Thermal Resistance Junction-to-Ambient Conditions IOUT=0.1A IOUT=0.1A VEN=0V VIN=5V～18V IOUT=0.1 to 2A Measure waveform at SW pin Measure waveform at SW pin Evaluate oscillation at SW pin Evaluate oscillation stop at SW pin VIN=5V，VFB=0V VIN=12V，VFB=0V VIN=12V，VOUT=5V，IOUT=2A Min. 3.6 0.782 2.5 300 10 2.0 75 0.3 Typ. 0.8 0.1 10 2 0.2 350 20 -10 90 2 110 70 92 65 Max. 18 0.818 0.5 4 0.5 400 0.8 105 5 150 100 o Unit V V uA A uA % % KHz KHz V uA uA uA ms mΩ % C /W DS-RS6513-03 Oct, 2007 www.Orister.com Page No. : 3/7 Typical Application Circuit RS6513 Note: VOUT = VFB x (1+RA/RB) RB=0.7K~5K ohm VIN=12V, IMAX = 2A VOUT L1 Value 2.5V 22uH 3.3V 27uH 5V 33uH Typical Performance Characteristics RS6513 Line Regulation (Vout=3.3V, Iout=0.2A) 3.450 3.400 3.350 3.300 3.250 3.200 3.150 3.100 3.050 3.5 4 5 6 8 10 12 14 16 18 RS6513 Load Regulation (Vin=12V) 3.364 3.362 Vout(V) Vout(V) 3.360 3.358 3.356 3.354 3.352 0.1A 0.5A 1A 1.5A 2A Vin(V) Iout(A) DS-RS6513-03 Oct, 2007 www.Orister.com Page No. : 4/7 Function Description PWM Control The RS6513 consists of DC/DC converters that employ a pulse-width modulation (PWM) system. In converters of the RS6513, the pulse width varies in a range from 0 to 100%, according to the load current. The ripple voltage produced by the switching can easily be removed through a filter because the switching frequency remains constant. Therefore, these converters provide a low-ripple power over broad ranges of input voltage and load current. Under Voltage Lockout The under voltage lockout circuit of the RS6513 assures that the high-side MOSFET driver outputs remain in the off state whenever the supply voltage drops below 3.3V. Normal operation resumes once VCC rises above 3.5V. RDS(ON) Current Limiting The current limit threshold is setting by the external resistor connecting from VCC supply to OCSET. The internal 100uA sink current crossing the resistor sets the voltage at the pin of OCSET. When the PWM voltage is less than the voltage at OCSET, an over-current condition is triggered. ILOAD× RDS(ON) =IOCSET ×ROCSET See above formula for setting the current limit value. DS-RS6513-03 Oct, 2007 www.Orister.com Page No. : 5/7 SOP-8L Dimension A G Marking: RS 6513 Pin 1 Index Date Code S 8 B 7 6 5 C 4 J H I Pin1 Index Control Code 2 3 Note: Green label is used for pb-free packing Material: • Lead solder plating: Sn60/Pb40 (Normal), Sn/3.0Ag/0.5Cu or Pure-Tin (Pb-free) • Mold Compound: Epoxy resin family, flammability solid burning class: UL94V-0 D E Part A K L N O Part A M DIM A B C D E F G H I J K L M N O Min. 4.85 3.85 5.80 1.22 0.37 3.74 1.45 4.80 0.05 0.30 0.19 0.37 0.23 0.08 0.00 Max. 5.10 3.95 6.20 1.32 0.47 3.88 1.65 5.10 0.20 0.70 0.25 0.52 0.28 0.13 0.15 *: Typical, Unit: mm F 8-Lead SOP-8L Plastic Surface Mounted Package Package Code: S Ordering Information PART NUMBER RS6513S PIN-PACKAGE SOP-8L DS-RS6513-03 Oct, 2007 www.Orister.com Page No. : 6/7 Soldering Methods for Orister’s Products 1. Storage environment: Temperature=10oC~35oC Humidity=65%±15% 2. Reflow soldering of surface-mount devices Figure 1: Temperature profile tP TP Ramp-up TL Tsmax Temperature tL Critical Zone TL to TP Tsmin tS Preheat Ramp-down 25 t 25oC to Peak Time Profile Feature Average ramp-up rate (TL to TP) Preheat - Temperature Min (Tsmin) - Temperature Max (Tsmax) - Time (min to max) (ts) Tsmax to TL - Ramp-up Rate Time maintained above: - Temperature (TL) - Time (tL) Peak Temperature (TP) Time within 5oC of actual Peak Temperature (tP) Ramp-down Rate Time 25oC to Peak Temperature 3. Flow (wave) soldering (solder dipping) Products Pb devices. Pb-Free devices. Sn-Pb Eutectic Assembly