XXRRPP66112244 NNoonn--SSyynncchhrroonnoouuss PPFFEETT SStteepp--DDoowwnn CCoonnttrroolllleerr January 2011 Rev. 1.1.0 GENERAL DESCRIPTION APPLICATIONS The XRP6124 is a non synchronous step down Point of Load Conversions (buck) controller for up to 5Amps point of Audio-Video Equipments loads. A wide 3V to 30V input voltage range allows for single supply operations from Industrial and Medical Equipments industry standard 3.3V, 5V, 12V and 24V Distributed Power Architecture power rails. With a proprietary Constant On-Time (COT) FEATURES control scheme, the XRP6124 provides extremely fast line and load transient response 5A Point-of-Load Capable while the operating frequency remains nearly Down to 1.2V Output Voltage Conversion constant. It requires no loop compensation Wide Input Voltage Range hence simplifying circuit implementation and reducing overall component count. The 3V to 18V: XRP6124 XRP76124 also implements an emulated ESR 4.5V to 30V: XRP6124HV circuitry allowing usage of ceramic output Constant On-Time Operations capacitors and insuring stable operations without the use of extra external components. Constant Frequency Operations No External Compensation Built-in soft start prevents high inrush currents while under voltage lock-out and output short Supports Ceramic Output Capacitors protections insure safe operations under Built-in 2ms Soft Start abnormal operating conditions. Short Circuit Protection The XRP6124 is available in a RoHS compliant, green/halogen free space-saving 5-pin SOT23 <1A shutdown current package. RoHS Compliant, Green/Halogen Free 5-pin SOT23 Package TYPICAL APPLICATION DIAGRAM Figure 1: XRP6124 Application Diagram Exar Corporation www.exar.com 48720 Kato Road, Fremont CA 94538, USA Tel. +1 510 668-7000 Fax. +1 510 668-7001 XXRRPP66112244 NNoonn--SSyynncchhrroonnoouuss PPFFEETT SStteepp--DDoowwnn CCoonnttrroolllleerr ABSOLUTE MAXIMUM RATINGS OPERATING RATINGS These are stress ratings only and functional operation of Input Voltage Range V (XRP6124) ................ 3.0V to 18V IN the device at these ratings or any other above those Input Voltage Range V (XRP6124HV) ............ 4.5V to 30V IN indicated in the operation sections of the specifications Junction Temperature Range .................... -40C to 125C below is not implied. Exposure to absolute maximum Thermal Resistance .....................................191C/W JA rating conditions for extended periods of time may affect reliability. V (XRP6124) ............................................ -0.3V to 20V IN V (XRP6124HV) ........................................ -0.3V to 32V IN GATE ...................................................... VIN-GATE<8V FB, EN ..................................................... -0.3V to 5.5V Storage Temperature .............................. -65C to 150C Power Dissipation ................................ Internally Limited Lead Temperature (Soldering, 10 sec) ................... 300C ESD Rating (HBM - Human Body Model) .................... 2kV ELECTRICAL SPECIFICATIONS Specifications are for an Operating Junction Temperature of T = 25C only limits applying over the full Operating Junction J Temperature range are denoted by a . Minimum and Maximum limits are guaranteed through test, design, or statistical correlation. Typical values represent the most likely parametric norm at T = 25C, and are provided for reference purposes J only. Unless otherwise indicated, V = 3.0V to 18V, T = 40C to 125C. IN J Parameter Min. Typ. Max. Units Conditions UVLO Turn-On Threshold 2.5 2.8 3.0 V XRP6124 UVLO Turn-On Threshold 3.8 4.2 4.5 V XRP6124HV UVLO Hysteresis 0.1 V 3.0 18 V XRP6124 Operating Input Voltage Range 4.5 30 V XRP6124HV Shutdown VIN Current 1.5 3 A EN=0V, V =12V IN Operating VIN Current 0.5 1 mA VFB=1.2V and after fault 0.792 0.8 0.808 V Reference Voltage 0.784 0.8 0.816 V VSC TH, Feedback pin Short 0.50 0.55 0.65 V Circuit Latch Threshold T , Switch On-Time 0.4 0.5 0.6 s V =12V, XRP6124 ON IN T , Switch On-Time 0.4 0.5 0.6 s V =24V, XRP6124HV ON IN T , Minimum Off-Time 250 350 ns V =12V OFF MIN IN Soft Start Time 2 ms EN Turn-On Threshold 2 V EN Turn-Off Threshold 1 V EN Bias Current 0.01 0.1 A Gate Driver Pull-Down 6 9 Resistance Gate Driver Pull-up Resistance 5 8 tr, gate rise time 45 ns C =1nF GATE tf, gate fall time 35 ns C =1nF GATE VIN - GATE voltage difference 5.5 6.4 8 V VIN=12V VIN - GATE voltage difference 2.6 V VIN=3.0V 2011 Exar Corporation 2/12 Rev. 1.1.0