LTC3810 100V Current Mode Synchronous Switching Regulator Controller FEATURES DESCRIPTION n High Voltage Operation: Up to 100V The LTC3810 is a synchronous step-down switching n Large 1 Gate Drivers regulator controller that can directly step-down voltages n No Current Sense Resistor Required from up to 100V, making it ideal for telecom and automo- n Dual N-Channel MOSFET Synchronous Drive tive applications. The LTC3810 uses a constant on-time n Extremely Fast Transient Response valley current control architecture to deliver very low duty n 0.5% 0.8V Voltage Reference cycles with accurate cycle-by-cycle current limit, without n Programmable Output Voltage Tracking/Soft-Start requiring a sense resistor. n Generates 10V Driver Supply from Input Supply A precise internal reference provides 0.5% DC accuracy. A n Synchronizable to External Clock high bandwidth (25MHz) error ampli er provides very fast n Selectable Pulse Skip Mode Operation line and load transient response. Large 1 gate drivers n Power Good Output Voltage Monitor allow the LTC3810 to drive multiple MOSFETs for higher n Adjustable On-Time/Frequency: t < 100ns ON(MIN) current applications. The operating frequency is selected n Adjustable Cycle-by-Cycle Current Limit by an external resistor and is compensated for variations n Programmable Undervoltage Lockout in V and can also be synchronized to an external clock IN n Output Overvoltage Protection for switching-noise sensitive applications. A shutdown pin n 28-Pin SSOP Package allows the LTC3810 to be turned off, reducing the supply current to 240A. APPLICATIONS Integrated bias control generates gate drive power from the n 48V Telecom and Base Station Power Supplies input supply during start-up and when an output short- n Networking Equipment, Servers circuit occurs, with the addition of a small external SOT23 n Automotive and Industrial Control Systems MOSFET. When in regulation, power is derived from the L, LT, LTC, LTM, Linear Technology, Burst Mode and the Linear logo are registered trademarks and No R is a trademark of Linear Technology Corporation. All other trademarks are the output for higher ef ciency. SENSE 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 V IN 100 15V TO 100V R ON + V = 50V C IN 261k 100k IN 22F V = 25V IN I ON M3 95 NDRV ZXMN10A07F V = 75V IN PGOOD BOOST LTC3810 90 V RNG M1 L1 TG Si7456DP 10H 0.1F C SS V MODE/SYNC OUT SW 1000pF 12V/6A 85 EXTV CC SS/TRACK DRV CC R FB1 SHDN INTV 14k CC D1 80 + + SENSE C I MBR1100 OUT 0 12 3 4 56 TH 47pF M2 270F LOAD (A) 200k BG Si7456DP V FB 3810 TA01b SENSE 5pF R SGND BGRTN FB2 1F 1k 3810 TA01 3810fc 1 EFFICIENCY (%)LTC3810 ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION (Note 1) TOP VIEW Supply Voltages I INTV , DRV ...................................... 0.3V to 14V 1 28 BOOST ON CC CC NC 2 27 TG (DRV - BGRTN), (BOOST - SW) ......... 0.3V to 14V CC NC 3 26 SW BOOST ................................................ 0.3V to 114V + V 4 25 SENSE ON BGRTN ....................................................... 5V to 0V V 5 24 NC RNG EXTV .................................................. 0.3V to 15V CC PGOOD 6 23 NC (NDRV - INTV ) Voltage ........................... 0.3V to 10V CC MODE/SYNC 7 22 NC + SW, SENSE Voltage ................................... 1V to 100V I 8 21 SENSE TH I Voltage ............................................... 0.3V to 100V ON V 9 20 BGRTN FB SS/TRACK Voltage ....................................... 0.3V to 5V PLL/LPF 10 19 BG PGOOD Voltage ............................................ 0.3V to 7V SS/TRACK 11 18 DRV CC V , V , MODE/SYNC, SHDN, SGND RNG ON 12 17 INTV CC UVIN Voltages ........................................ 0.3V to 14V SHDN 13 16 EXTV CC PLL/LPF, FB Voltages ................................. 0.3V to 2.7V UVIN 14 15 NDRV TG, BG, INTV , EXTV RMS Currents .................50mA CC CC G PACKAGE 28-LEAD PLASTIC SSOP Operating Junction Temperature Range T = 125C, = 80C/W JMAX JA (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 LTC3810EG PBF LTC3810EG TRPBF LTC3810EG 28-Lead Plastic SSOP 40C to 125C LTC3810IG PBF LTC3810IG TRPBF LTC3810IG 28-Lead Plastic SSOP 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: