LT1767/LT1767-1.8/ LT1767-2.5/LT1767-3.3/LT1767-5 Monolithic 1.5A, 1.25MHz Step-Down Switching Regulators Fea T Descrip T n 1.5A Switch in a Small MSOP Package The LT 1767 is a 1.25MHz monolithic buck switching n Constant 1.25MHz Switching Frequency regulator. A high efficiency 1.5A, 0.22 switch is included n High Power Exposed Pad (MS8E) Package on the die together with all the control circuitry required n Wide Operating Voltage Range: 3V to 25V to complete a high frequency, current mode switching n High Efficiency 0.22 Switch regulator. Current mode control provides fast transient n 1.2V Feedback Reference Voltage response and excellent loop stability. n Fixed Output Voltages of 1.8V, 2.5V, 3.3V, 5V New design techniques achieve high efficiency at high n 2% Overall Output Tolerance switching frequencies over a wide operating range. A n Uses Low Prolfi e Surface Mount Components low dropout internal regulator maintains consistent per- n Low Shutdown Current: 6A formance over a wide range of inputs from 24V systems n Synchronizable to 2MHz to Li-Ion batteries. An operating supply current of 1mA n Current Mode Loop Control improves efficiency, especially at lower output currents. n Constant Maximum Switch Current Rating at All Duty Shutdown reduces quiescent current to 6A. Maximum Cycles* switch current remains constant at all duty cycles. Syn- chronization allows an external logic level signal to increase the internal oscillator from 1.5MHz to 2MHz. a T n The LT1767 is available in an 8-pin MSOP fused lead-frame DSL Modems n package and a low thermal resistance exposed pad package. Portable Computers n Full cycle-by-cycle current limit and thermal shutdown are Wall Adapters n provided. High frequency operation allows the reduction Battery-Powered Systems n of input and output filtering components and permits the Distributed Power use of chip inductors. L, LT, LTC, LTM, Linear Technology, the Linear logo and Burst Mode are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. Protected by U.S. Patents, including 6611131, 6498466. Typical a T Efficiency vs Load Current 12V to 3.3V Step-Down Converter 95 D2 V = 10V CMDSH-3 IN V = 5V OUT 90 C2 0.1F L1 85 5H BOOST OUTPUT V IN V V 3.3V IN SW 12V C3 1.2A* 80 OPEN LT1767-3.3 2.2F OR CERAMIC SHDN FB HIGH SYNC GND V C = ON 75 C1 C D1 10F C 1.5nF UPS120 CERAMIC R C 70 4.7k 0 0.2 0.4 0.6 0.8 1 1.2 1.4 LOAD CURRENT (A) *MAXIMUM OUTPUT CURRENT IS SUBJECT TO THERMAL DERATING. 1767 TA01 1767 TA01a 1767fb 1 For more information www.linear.com/LT1767 EFFICIENCY (%) ion pplica ions pplica ion uresLT1767/LT1767-1.8/ LT1767-2.5/LT1767-3.3/LT1767-5 a Te Maxi Mu M r a T (Note 1) Input Voltage ........................................................... 25V SYNC Pin Current ................................................... 1mA BOOST Pin Above SW ............................................. 20V Operating Junction Temperature Range (Note 2) Max BOOST Pin Voltage ............................................35V LT1767E ........................................... 40C to 125C SHDN Pin ................................................................. 25V Storage Temperature Range ................. 65C to 150C FB Pin Voltage ........................................................... 6V Lead Temperature (Soldering, 10 sec) ................ 300C FB Pin Current ......................................................... 1mA p c F T TOP VIEW TOP VIEW BOOST 1 8 SYNC BOOST 1 8 SYNC V 2 7 V V 2 7 V IN C IN C SW 3 6 FB SW 3 6 FB 5 5 GND 4 SHDN GND 4 SHDN MS8 PACKAGE MS8E PACKAGE 8-LEAD PLASTIC MSOP 8-LEAD PLASTIC MSOP T = 125C, = 110C/W T = 125C, = 40C/W JMAX JA JMAX JA GROUND PIN CONNECTED TO LARGE COPPER AREA GROUND PIN CONNECTED TO LARGE COPPER AREA ON PCB o r D i n F Ma T LEAD FREE FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE LT1767EMS8 PBF LT1767EMS8 TRPBF LTLS 8-Lead Plastic MSOP 40C to 125C LT1767EMS8-1.8 PBF LT1767EMS8-1.8 TRPBF LTWG 8-Lead Plastic MSOP 40C to 125C LT1767EMS8-2.5 PBF LT1767EMS8-2.5 TRPBF LTWD 8-Lead Plastic MSOP 40C to 125C LT1767EMS8-3.3 PBF LT1767EMS8-3.3 TRPBF LTWE 8-Lead Plastic MSOP 40C to 125C LT1767EMS8-5 PBF LT1767EMS8-5 TRPBF LTWF 8-Lead Plastic MSOP 40C to 125C LT1767EMS8E PBF LT1767EMS8E TRPBF LTZG 8-Lead Plastic MSOP, Exposed Pad 40C to 125C LT1767EMS8E-1.8 PBF LT1767EMS8E-1.8 TRPBF LTZH 8-Lead Plastic MSOP, Exposed Pad 40C to 125C LT1767EMS8E-2.5 PBF LT1767EMS8E-2.5 TRPBF LTZJ 8-Lead Plastic MSOP, Exposed Pad 40C to 125C LT1767EMS8E-3.3 PBF LT1767EMS8E-3.3 TRPBF LTZK 8-Lead Plastic MSOP, Exposed Pad 40C to 125C LT1767EMS8E-5 PBF LT1767EMS8E-5 TRPBF LTZL 8-Lead Plastic MSOP, Exposed Pad 40C to 125C Consult LTC Marketing for parts specified with wider operating temperature ranges. Consult LTC Marketing for information on nonstandard lead based finish parts. For more information on lead free part marking, go to: