LTC3812-5 60V Current Mode Synchronous Switching Regulator Controller FEATURES DESCRIPTION The LTC3812-5 is a synchronous step-down switching n High Voltage Operation: Up to 60V regulator controller that can directly step down voltages n Large 1 Gate Drivers from up to 60V input, making it ideal for telecom and n No Current Sense Resistor Required automotive applications. The LTC3812-5 uses a constant n Dual N-Channel MOSFET Synchronous Drive on-time valley current control architecture to deliver very n Extremely Fast Transient Response low duty cycles with accurate cycle-by-cycle current limit n 0.5% 0.8V Voltage Reference without requiring a sense resistor. n Programmable Soft-Start n Generates 5.5V Driver Supply A precise internal reference provides 0.5% DC accuracy. n Selectable Pulse-Skipping Mode Operation A high bandwidth (25MHz) error ampli er provides very n Power Good Output Voltage Monitor fast line and load transient response. Large 1 gate driv- n Adjustable On-Time/Frequency: t < 100ns ers allow the LTC3812-5 to drive large power MOSFETs ON(MIN) n Adjustable Cycle-by-Cycle Current Limit for higher current applications. The operating frequency n Undervoltage Lockout On Driver Supply is selected by an external resistor and is compensated for n Output Overvoltage Protection variations in V . A shutdown pin allows the LTC3812-5 to IN n Thermally Enhanced 16-Pin TSSOP Package be turned off reducing the supply current to <230A. Integrated bias control generates gate drive power from APPLICATIONS the input supply during start-up and when an output short- n 48V Telecom and Base Station Power Supplies circuit occurs, with the addition of a small external SOT23 n Networking Equipment, Servers MOSFET. When in regulation, power is derived from the n Automotive and Industrial Control Systems output for higher ef ciency. L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. Protected by U.S. Patents including 5481178, 5847554, 6304066, 6476589, 6580258, 6677210, 6774611. TYPICAL APPLICATION High Ef ciency High Voltage Step-Down Converter Ef ciency vs Load Current 100 V IN 6V TO 60V R ON + 100k C 110k IN V = 12V IN 22F 95 M3 I NDRV ON ZXMN- 100k 10A07F V = 42V IN BOOST PGOOD 90 V = 24V IN PGOOD LTC3812-5 M1 L1 V TG RNG Si7850DP 0.1F 4.7H V OUT 85 FCB SW 5V 5A EXTV CC INTV RUN/SS CC M2 80 1000pF I BG TH Si7850DP 10k 0 12 3 4 56 47pF + LOAD CURRENT (A) 200k D1 C OUT 1F MBR1100 270F V FB PGND 38125 TA01b SGND 5pF 1.89k 38125 TA01 38125fc 1 EFFICIENCY (%)LTC3812-5 ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION (Note 1) TOP VIEW Supply Voltages I 1 16 BOOST ON INTV ................................................... 0.3V to 14V CC V 2 15 TG RNG (INTV PGND), (BOOST SW) ......... 0.3V to 14V CC PGOOD 3 14 SW BOOST (Continuous) ............................. 0.3V to 85V FCB 4 13 PGND 17 BOOST (400ms) .................................. 0.3V to 95V I 5 12 BG TH EXTV .................................................. 0.3V to 15V CC V 6 11 INTV FB CC (EXTV INTV ) .................................. 12V to 12V CC CC RUN/SS 7 10 EXTV CC (NDRV INTV ) Voltage ........................... 0.3V to 10V CC SGND 8 9 NDRV SW Voltage (Continuous) .............................. 1V to 70V FE PACKAGE SW Voltage (400ms) ..................................... 1V to 80V 16-LEAD PLASTIC TSSOP T = 125C, = 38C/W JMAX JA I Voltage (Continuous) ........................... 0.3V to 70V ON EXPOSED PAD (PIN 17) IS GND, MUST BE SOLDERED TO PCB I Voltage (400ms) .................................. 0.3V to 80V ON RUN/SS Voltage ........................................... 0.3V to 5V PGOOD Voltage ............................................ 0.3V to 7V V , FCB Voltages .................................... 0.3V to 14V RNG FB Voltage ................................................. 0.3V to 2.7V TG, BG, INTV , EXTV RMS Currents .................50mA CC CC Operating Junction Temperature Range (Notes 2, 3, 7) ........................................ 40C to 125C Storage Temperature Range ................... 65C to 150C Lead Temperature (Soldering, 10 sec) .................. 300C ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LTC3812EFE-5 PBF LTC3812EFE-5 TRPBF 3812EFE-5 16-Lead Plastic TSSOP 40C to 125C LTC3812IFE-5 PBF LTC3812IFE-5 TRPBF 3812IFE-5 16-Lead Plastic TSSOP 40C to 125C Consult LTC Marketing for parts speci ed with wider operating temperature ranges. Consult LTC Marketing for information on non-standard lead based nish parts. For more information on lead free part marking, go to: