SC4525DSETRT Semtech

SC4525D 18V, 3A, 350kHz Step-Down Switching Regulator POWER MANAGEMENT Features Description Input range: 3V to 8V The SC4525D is a 350kHz constant frequency peak 3A Output Current current-mode step-down switching regulator capable of 350kHz Fixed Switching Frequency producing 3A output current from an input ranging from Precision V Feedback Voltage 3V to 8V . The SC4525D is suitable for next generation Peak Current-Mode Control XDSL modems, high-definition TVs and various point of Cycle-by-Cycle Current Limiting load applications. Hiccup Overload Protection with Frequency Foldback Soft-Start and Enable Peak current-mode PWM control employed in the Thermal Shutdown SC4525D achieves fast transient response with simple loop Thermally Enhanced 8-pin SOIC Package compensation. Cycle-by-cycle current limiting and hiccup Fully RoHS and WEEE compliant overload protection reduces power dissipation during output overload. Soft-start function reduces input start- up current and prevents the output from overshooting during power-up. Applications 1122 The SC4525D is available in SOIC-8 EDP package. XDSL and Cable Modems Set Top Boxes Point of Load Applications CPE Equipment DSP Power Supplies Fig.1b: 350kHz 10-16V to 5V/3A Step-Down Converter (Front Page Efficiency w/12Vin) LCD and Plasma TVs SC4525A Typical Application Circuit Efficiency D1 90 10 V 16V V IN 85 1N 4148 C4 C1 10mF V =12V 0.33 mF 80 IN BST IN L1 OUT SW 75 10 mH 5V/3A R4 SC4525D 70 SS/EN 33.2k 65 FB COMP RSET GND 60 55 C7 D2 R6 C2 R5 R7 20BQ030 8.25k 47mF C8 11.5k 60.4 k 22 nF 50 pF 47 C5 2.2nF 45 40 L1 : Coiltronics CD1-100 C2 : Murata GRM31CR60J 476M 0 0.5 1 1.5 2 2.5 3 C4 : Murata GRM31CR61E 106K Load Current (A) Figure 1 350kHz 10V - 16V to 5V/3A Step-down Converter Efficiency of the 1MHz 10V-28V to 5V/3A Step-Down Converter (Front Page) Revision 5.0 20 S emtech Corporation Fig.1a : 350 kHz1 0-V 16 V to5 V/3 A Ste-p Down Convert(er Front Page Schema)tic Efficiency (%)SC4525D Pin Configuration Ordering Information Device Package ( )(2) SC4525DSETRT SOIC-8 EDP SW 1 8 BST SC4525DEVB Evaluation Board IN 2 7 FB Notes: 9 RSET 3 6 COMP () A vailable in tape and reel only. A reel contains 2,500 devices. (2) Available in lead-free package only. Device is fully WEEE and RoHS GND 4 5 SS/EN compliant and halogen-free. (8 - Pin SOIC - EDP) Marking Information yyww=Date code (Example: 0752) xxxxx=Semtech Lot No. (Example: E90 0) 2