XXRRPP66114422 Synchronous Step-Down Controller with DDR Synchronous Step-Down Controller with DDR MMeemmoorryy TTeerrmmiinnaattiioonn March 2010 Rev. 1.0.0 GENERAL DESCRIPTION APPLICATIONS The XRP6142 is a synchronous step down High-Power Point-of-Loads Converters switching controller for over 15 Amps point-of- Audio-Video Equipments loads converters and optimized to generate and support DDR I, II and III memory FPGA and DSP Power Supplies voltages requirements. DDR Memory Based Embedded Systems Optimized to operate from standard 3.3V and 5V rails, the XRP6142 supports conversions FEATURES down to 0.5V from an input voltage as low as 1V and can reach efficiencies of up to 96%. Over 15A Point-of-Load Capable Based on a constant on-time control scheme Down to 0.5V Output Voltage Conversion and operating at a constant switching Up to 96% Efficiency frequency over the whole input voltage range, it provides excellent load transient response Wide 1.0V-5.5V Input Voltage Range while requiring no external compensation Conversions components. Three selectable on-time options Single Input 3.3V and 5V rails Operations allow for further switching frequency, solution Constant On-Time Operations footprint and efficiency optimization. Constant Frequency Operations Dedicated support for DDR I, II and II No External Compensation memories is also provided. The XRP6142 easily generates V (V ) or V voltages DDQ DD TT DDR I, II & III Termination Support while an on board buffer provides the buffered V /V or V Voltages Generation DDQ DD TT V reference voltage. TT Buffered V Ref. Voltage Generation TT Under-voltage Lock out, short-circuit and Soft-Start and Enable Functions over-current and over-temperature protection insure safe operations under abnormal UVLO, Short Circuit and Over Current operating conditions. Protection The XRP6142 is available in a compact RoHS RoHS Compliant Green/Halogen Free compliant green/halogen free 16-pin QFN 3mm x 3mm 16-Pin QFN Package package. TYPICAL APPLICATION DIAGRAM Operation as DDR Supply V IN VDDQ C IN QT V IN 3V-5.5V GH V L1 V ACNTL VTT CC OUT BST VOUT V IN EN SW C R3 SP2996B OUT XRP6142 CFF R1 RLIM ILIM REF EN V REF R2 QB R4 GL REFIN CS GND GND PGND FB VDDQ/2 AGND VREF VTTREF Thermal Pad Figure. 1: XRP6142 as a Step-Down Converter or a DDR Supply Exar Corporation www.exar.com 48720 Kato Road, Fremont CA 94538, USA Tel. +1 510 668-7000 Fax. +1 510 668-7001 XXRRPP66114422 Synchronous Step-Down Controller with DDR Synchronous Step-Down Controller with DDR MMeemmoorryy TTeerrmmiinnaattiioonn ABSOLUTE MAXIMUM RATINGS OPERATING RATINGS These are stress ratings only, and functional operation of Input Voltage Range V .............................. 3.0V to 5.5V CC the device at these ratings or any other above those Input Voltage Range V ............................... 1.0V to 5.5V 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 ................................... 33.3C/W JA rating conditions for extended periods of time may affect reliability. V ...................................................................... 7.0V CC V ....................................................................... 7.0V IN BST .................................................................... 13.5V SW ............................................................. -1V to 7.0V BST-SW ...................................................... -0.3V to 6V All other pins ..................................... -0.3V to V +0.3V CC Storage Temperature .............................. -65C to 150C Power Dissipation ................................ Internally Limited Lead Temperature (Soldering, 10 sec) ................... 300C ESD Rating (HBM - Human Body Model) .................... 2kV ESD Rating (MM - Machine Model) ........................... 500V ELECTRICAL SPECIFICATIONS Specifications are for an Operating Junction Temperature of T = 25C 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 = V = 3.3V. CC IN Parameter Min. Typ. Max. Units Conditions 0.5 0.505 V 0.495 V , Reference Voltage REF 0.5 0.508 V 0.492 V offset 7 mV V = V FB REFIN REF V , Voltage Range VREF 1.3 V REFIN V , Input Impedance 60 M DDQ/2 V , Output Error +1.25 % V = 0.75V, I =0mA TTREF -1.25 DDQ/2 VTTR Sourcing: V =0, V =V TTREF DDQ/2 REF V Current Limit 40 65 mA TTREF 20 Sinking: V =2V TTREF I , Operating Quiescent Current 400 600 A Not switching, V =V +0.1V Q FB REFIN I , Shutdown current 0.1 A EN=0V OFF 0.4 0.5 0.6 XR6142EL0-5-F (T =500ns) ON T , Switch On-Time 1.0 1.2 s XR6142EL1-0-F (T =1000ns) ON 0.8 ON 2.0 2.4 XR6142EL2-0-F (T =2000ns) 1.6 ON T , Minimum Off-Time 300 400 ns All T options OFF MIN ON T , Gate Drive Dead-Time 50 ns D V , EN Pin Rising Threshold 1.2 1.25 V IH EN 1.15 V , EN Pin Hysteresis 50 200 mV EN HYS I , Feedback Pin Bias Current V =2.0V 50 nA FB FB V , Under-Voltage Lockout 2.8 3.0 V V rising edge CCUVLO CC V , Under-Voltage Lock CCUVLO HYS 500 mV out Hysteresis V , Feedback Pin Short SC TH 55 65 75 % % of VREFIN Circuit Latch Threshold ILIM Pin Source Current 42.5 50 57.5 A ILIM Current Temperature 0.3 %/C Coefficient V Current Limit Trip Level 0 +20 mV ILIM -20 Current Limit Blanking 130 ns GL Rising > 1.0V 2010 Exar Corporation Page 2 of 17 Rev. 1.0.0