LP6482SOF

Preliminary Datasheet LP6482 340KHz, 2A Step-down Converter With Soft-Start General Description Features The LP6482 contains an independent 340KHz  Input Voltage Range: 4.5V to 30V  Output Voltage Range: 0.6V to 12V and a synchronous rectifier for high efficiency  2A Load Current without an external Schottky diode. The converter  Up to 95% Efficiency  340KHz Switching Frequency  Short Circuit Protection cycle-by-cycle limit with current mode control.  Thermal Fault Protection The LP6482 is available in a SOP8 package and is  SOP8 Package  RoHS Compliant and 100% Lead (Pb)-Free constant frequency, current mode, PWM step -down converters. The converter integrates a main switch can supply 2A of load current. The LP6482 can also run at 98% duty cycle for low dropout applications. It provides fast transient response and rated over the -40°C to 85°C temperature range. Order Information Applications LP6482 □ □ □ F: Pb-Free Package Type  Portable Media Players  Cellular and Smart mobile phone  PDA/DSC  GPS Applications SO: SOP8 Marking Information Device Marking Package Shipping LP6482SOF LPS SO:SOP8 4K/REEL LP6482 YWX Y: Year code. W: Week code. X: Batch numbers. LP6482-00 May.-2018 Email: marketing@lowpowersemi.com www.lowpowersemi.com Page 1 of 7 Preliminary Datasheet LP6482 Functional Pin Description Package Type Pin Configurations NC 1 8 NC VIN 2 7 EN SW 3 6 NC GND 4 5 FB SOP-8 Pin Description Pin Name Description 1/6/8 NC No Connector. 2 VIN Supply Input. 3 SW 4 GND 5 FB 7 EN Switch Mode Connection to Inductor. This pin connects to the drains of the internal main and synchronous power MOSFET switches. Ground. Feedback Input. Connect FB to the center point of the external resistor divider. Normal voltage for this pin is 0.6V. Enable Control Input. Drive EN above 2.5V to turn on the Channel. Drive EN below 0.4V to turn it off (shutdown current < 0.1µA). Typical Application Circuit VIN Vout VIN SW 10uF*2 10uH 10uF*2 EN GND R1 FB R2 LP6482-00 May.-2018 Email: marketing@lowpowersemi.com www.lowpowersemi.com Page 2 of 7 Preliminary Datasheet LP6482 Function Diagram Absolute Maximum Ratings Note 1  VIN/SW/EN to GND -------------------------------------------------------------------------------------------------------------- 36V  FB to GND (VFB) ------------------------------------------------------------------------------------------------------- -0.3V to 6V  Junction Temperature ------------------------------------------------------------------------------------------------------- 150°C  Storage Temperature --------------------------------------------------------------------------------------------- -65℃ to 165℃  Operating Ambient Temperature Range (TA) --------------------------------------------------------------- -40℃ to 85°C  Maximum Soldering Temperature (at leads, 10sec) ----------------------------------------------------------------- 260℃ Note 1. Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Thermal Information  Maximum Power Dissipation (SOP8, PD,TA=25°C) ------------------------------------------------------------------- 1.5W  Thermal Resistance (SOP8, θJA) --------------------------------------------------------------------------------------- 80℃/W ESD Susceptibility  HBM(Human Body Mode) ----------------------------------------------------------------------------------------------------- 2KV  MM(Machine Mode) ------------------------------------------------------------------------------------------------------------ 200V LP6482-00 May.-2018 Email: marketing@lowpowersemi.com www.lowpowersemi.com Page 3 of 7 Preliminary Datasheet LP6482 Electrical Characteristics VIN=12V, VEN=5V, L=10uH,TA=25℃, unless otherwise noted Symbol Parameter Condition Min Typ VIN Input Voltage VIN-OVP VIN OVP Voltage Lockout Threshold VOUT Output Voltage Range IQ Quiescent Current VIN=12V 10 mA ISHDN Shutdown Current EN=GND 10 µA ILIM P-Channel Current Limit RDS(ON)_H High-Side Switch On Resistance 80 mΩ RDS(ON)_L Low-Side Switch On Resistance 60 mΩ ILX_LEAK LX Leakage Current VEN=0V, VSW=0 or 5V, VIN=5V 1 µA VFB Feedback Threshold Voltage Accuracy VIN=12V IFB FB Leakage Current VOUT=5.0V fOSC Oscillator Frequency tS Startup Time TSD 4.5 Max Units 30 V 12 V 32 0.6 3 0.588 A 0.6 0.612 V 30 nA 340 KHz 2.7 mS Over-Temperature Shutdown Threshold 150 ℃ THYS Over-Temperature Shutdown Hysteresis 20 ℃ VEN(L) Enable Threshold Low VEN(H) Enable Threshold High IEN Enable Current From Enable to Output Regulation 1 2.5 VIN=12V, VEN=12V V V 5 µA Note: Output Voltage: VOUT = VFB × ( 1 + R1 / R2 ) Volts; LP6482-00 May.-2018 Email: marketing@lowpowersemi.com www.lowpowersemi.com Page 4 of 7 Preliminary Datasheet LP6482 Typical Operating Characteristics Efficiency VS. Iout @ Vout=5.1V 100 95 90 eff（%） 85 80 75 70 65 Vin=8V 60 Vin=12V 55 Vin=18V 50 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2.0 Iout（A） LP6482-00 May.-2018 Email: marketing@lowpowersemi.com www.lowpowersemi.com Page 5 of 7 Preliminary Datasheet LP6482 ripple current and lower output ripple voltage. Application Information The LP6482 operates by a constant frequency, current mode architecture. The output voltage is set by an external divider returned to the FB pin. An error amplifier compares the divided output voltage with a reference voltage of 0.6V and adjusts the peak inductor current accordingly. However, the larger value inductor has a larger physical size, higher series resistance, and lower saturation current. Choose an inductor that does not saturate under the worst-case load conditions. A good rule for determining the inductance is to allow the peak-to-peak ripple current in the inductor to be approximately 30% of the maximum load current. Thermal Protection The inductance value can be calculated by the The total power dissipation in LP6482 is limited by a equation: thermal protection circuit. When the device temperature rises to approximately 150℃, this circuit turns off the output, allowing the IC to cool. The L=(VOUT)×(VIN-VOUT)/(VIN×f×∆I) Output Capacitor thermal protection circuit can protect the device from The output capacitor is required to maintain the DC being damaged by overheating in the event of fault output voltage. Low ESR capacitors are preferred to conditions. Continuously running the LP6482 into keep thermal shutdown degrades device reliability. characteristics of the output capacitor also affect the the output voltage ripple low. The stability of the regulator control loop. Ceramic, Setting Output Voltage tantalum, or low ESR electrolytic capacitors are The output voltage is set with a resistor divider from recommended. In the case of ceramic capacitors, the the output node to the FB pin. It is recommended to impedance at the switching frequency is dominated use divider resistors with 1% tolerance or better. To by the capacitance. The output voltage ripple is improve efficiency at very light loads consider using estimated to be: larger value resistors. If the values are too high the VRIPPLE=1.4×VIN×(fLC/f)2 regulator is more susceptible to noise and voltage errors from the FB input current are noticeable. For Where VRIPPLE is the output ripple voltage, V IN is the most applications, a resistor in the 10kΩ to 1MΩ input voltage, fLC is the resonant frequency of the LC range is suggested for RUP and RDN. The output filter, f is the switching frequency. In the case of voltage is established by the following equations tantalum or low ESR electrolytic capacitors, the ESR VOUT=0.6V×(1+R1/R2) dominates the impedance at the switching frequency, and so the output ripple is calculated as: Where VREF is 0.6V. VRIPPLE≈∆I×RESR Inductor Selection The inductor is required to supply constant current to the output load while being driven by the switched Where VRIPPLE is the output voltage ripple, ΔI is the inductor ripple current, and RESR is the equivalent series resistance of the output capacitors. input voltage. A larger value inductor results in less LP6482-00 May.-2018 Email: marketing@lowpowersemi.com www.lowpowersemi.com Page 6 of 7 Preliminary Datasheet LP6482 Packaging Information SOP8 LP6482-00 May.-2018 Email: marketing@lowpowersemi.com www.lowpowersemi.com Page 7 of 7