LTC3866 Current Mode Synchronous Controller for Sub Milliohm DCR Sensing Fea T Descrip T n Sub Milliohm DCR Current Sensing The LTC 3866 is a single phase current mode synchronous n High Efficiency: Up to 95% step-down switching regulator controller that drives all n Selectable Current Sensing Limit N-channel power MOSFET switches. It employs a unique n Programmable DCR Temperature Compensation architecture which enhances the signal-to-noise ratio of n Die Overtemperature Thermal Shutdown the current sense signal, allowing the use of a very low n 0.5% 0.6V Output Voltage Accuracy DC resistance power inductor to maximize the efficiency n Programmable Fixed Frequency 250kHz to 770kHz in high current applications. This feature also reduces the n High Speed Differential Remote Sense Amplifier switching jitter commonly found in low DCR applications. n Wide Input Voltage Range: 4.5V to 38V The LTC3866 also includes a high speed remote sense dif- n Output Voltage Range: 0.6V to 3.5V with Diffamp ferential amplifier, a programmable current sense limit that n Adjustable Soft-Start or Output Voltage Tracking can be selected to 10mV, 15mV, 20mV, 25mV or 30mV, n Foldback Output Current Limit and DCR temperature compensation to limit the maximum n Short-Circuit Soft Recovery output current precisely over temperature. n Output Overvoltage Protection The LTC3866 also features a precise 0.6V reference with a n 24-Lead (4mm 4mm) QFN and 24-Lead FE Packages guaranteed limit of 0.5% that provides an accurate output voltage from 0.6V to 3.5V. A 4.5V to 38V input voltage range allows it to support a wide variety of bus voltages a T and various types of batteries. n Computer Systems The LTC3866 is offered in a low profile 24-lead 4mm n Telecom Systems 4mm QFN and 24-lead exposed pad FE packages. n Industrial and Medical Instruments n L, LT, LTC, LTM, Burst Mode, OPTI-LOOP, Linear Technology and the Linear logo are DC Power Distribution Systems registered trademarks and No R is a trademark of Analog Devices, Inc. All other SENSE trademarks are the property of their respective owners. Protected by U.S. Patents, including 5481178, 5705919, 5929620, 6177787, 6580258, 6498466, 6611131, patent pending. Typical a T High Efficiency, 1.5V/30A Step-Down Converter with Very Low DCR Sensing Efficiency vs Load Current and Mode 100k V IN FREQ MODE/PLLIN 4.5V TO 20V 100 0.1F 220F RUN PGOOD 4.7F 90 TK/SS ITEMP ITH EXTV 80 CC LTC3866 V V FB IN 70 DIFFOUT INTV CC 60 0.1F DIFFP BOOST 50 0.33H V = 12V IN 30.1k DIFFN TG DCR = 0.32m V = 1.5V V OUT OUT 40 + 1.5V L = 0.33H SW SNSD C1 30A 30 (DCR = 0.32m TYP) C BG OUT 220pF 20k SNS 220nF CCM 470F R1 + R2 20 10k PGND SNSA PULSE SKIPPING 2 4.64k C2 931 Burst Mode ILIM CLKOUT 10 1.5nF 220nF OPERATION SGND 0 0.01 0.1 1 10 100 LOAD CURRENT (A) 3866 TA01b 3866 TA01a 3866fc 1 For more information www.linear.com/LTC3866 EFFICIENCY (%) ion pplica ions pplica ion uresLTC3866 a T e Maxi Mu M r a T (Note 1) Input Supply Voltage .................................. 0.3V to 40V DIFFP, DIFFN .........................................0.3V to INTV CC Topside Driver Voltage (BOOST) ................ 0.3V to 46V ITEMP, ITH, V Voltages ....................0.3V to INTV FB CC Switch Voltage(SW) ..................................... 5V to 40V INTV Peak Output Current ..............................100mA CC INTV , EXTV , RUN, PGOOD, Operating Junction Temperature Range CC CC BOOST-SW Voltages .................................... 0.3V to 6V (Notes 2, 4) ............................................ 40C to 125C + + SNSD , SNSA , SNS Voltages .............0.3V to INTV Storage Temperature Range .................. 65C to 125C CC MODE/PLLIN, ILIM, TK/SS, FREQ, Lead Temperature (Soldering, 10 sec) DIFFOUT Voltages .................................0.3V to INTV FE Package .......................................................300C CC p c F T TOP VIEW TOP VIEW 1 24 MODE/PLLIN FREQ 2 23 PGOOD RUN 3 22 ITEMP TK/SS 24 23 22 21 20 19 4 21 EXTV ITH CC ITH 1 18 EXTV CC 5 20 V V FB IN V 2 17 V FB IN 6 19 INTV DIFFOUT 25 CC DIFFOUT 3 16 INTV CC SGND 25 7 18 BOOST DIFFN SGND DIFFN 4 15 BOOST 8 17 TG DIFFP DIFFP 5 14 TG + 9 16 SW SNSD + SNSD 6 13 SW 10 15 BG SNS 7 8 9 10 11 12 + 11 14 PGND SNSA 12 13 CLKOUT ILIM FE PACKAGE UF PACKAGE 24-LEAD PLASTIC TSSOP 24-LEAD (4mm 4mm) PLASTIC QFN = 33C/W, = 10C/W JA JC = 47C/W, = 4.5C/W JA JC EXPOSED PAD (PIN 25) IS SGND, MUST BE SOLDERED TO PCB EXPOSED PAD (PIN 25) IS SGND, MUST BE SOLDERED TO PCB o r D i n F Ma T