LT3695 Series 1A Fault Tolerant Micropower Step-Down Regulator FEATURES DESCRIPTION n Wide Input Range: The LT 3695 series are adjustable frequency (250kHz to Operation from 3.6V to 36V 2.2MHz) monolithic buck switching regulators that accept Overvoltage Lockout Protects Circuits Through input voltages up to 36V and can safely sustain transient 60V Transients voltages up to 60V. The devices include a high ef ciency n FMEA Fault Tolerant: switch, a boost diode, and the necessary oscillator, control Output Stays at or Below Regulation Voltage and logic circuitry. Current mode topology is used for fast During Adjacent Pin Short or When a Pin Is Left transient response and good loop stability. A SYNC pin Floating allows the user to synchronize the part to an external clock, n 1A Output Current and to choose between low ripple Burst Mode operation n Low Ripple (< 15mV ) Burst Mode Operation and standard PWM operation. P-P I = 75A for 12V to 3.3V with No Load Q IN OUT The LT3695 regulators tolerate adjacent pin shorts or n Adjustable Switching Frequency: 250kHz to 2.2MHz an open pin without raising the output voltage above its n Short-Circuit Protected programmed value. n Synchronizable Between 300kHz and 2.2MHz n Output Voltage: 0.8V to 20V Low ripple Burst Mode operation maintains high ef - n Power Good Flag ciency at low output currents while keeping output ripple n Fixed Output Voltage Versions for 3.3V and 5V Available below 15mV in a typical application. Shutdown reduces n Small, Thermally Enhanced 16-Pin MSOP Package input supply current to less than 1A while a resistor and capacitor on the RUN/SS pin provide a controlled output APPLICATIONS voltage ramp (soft-start). Protection circuitry senses the current in the power switch and external Schottky catch n Automotive Battery Regulation diode to protect the LT3695 regulators against short-circuit n Automotive Entertainment Systems conditions. Frequency foldback and thermal shutdown n Distributed Supply Regulation provide additional protection. n Industrial Supplies L, LT, LTC, LTM, Burst Mode, Linear Technology and the Linear logo are registered trademarks of The LT3695 series is available in a thermally enhanced Linear Technology Corporation. All other trademarks are the property of their respective owners. 16-pin MSOP package. TYPICAL APPLICATION Ef ciency 100 5V Step-Down Converter V IN V V = 5V OUT OUT 6.9V TO 36V 5V 90 TRANSIENT TO 60V 0.9A, V > 6.9V IN V BD IN 1A, V > 12V IN V = 3.3V 2.2F OUT ON OFF RUN/SS BOOST 80 0.22F 10H V SW C LT3695 RT 70 PG DA 16.2k 40.2k 536k SYNC FB 60 V = 12V IN GND PGND 470pF 102k 10F L = 10H f = 800kHz 50 3695 TA01a f = 800kHz 0 0.2 0.4 0.6 0.8 1 LOAD CURRENT (A) 3695 TA01b 3695fa 1 EFFICIENCY (%)LT3695 Series ABSOLUTE MAXIMUM RATINGS (Notes 1, 2) V , RUN/SS Voltage (Note 3) ...................................60V OUT1, OUT2 Voltage (LT3695-3.3, LT3695-5) ...........16V IN BOOST Pin Voltage ...................................................50V PG Voltage ................................................................30V BOOST Pin Above SW Pin .........................................30V Operating Junction Temperature Range (Notes 4, 5) BD Voltage (LT3695) .................................................30V LT3695E ............................................. 40C to 125C RT, V Voltage ............................................................5V LT3695I .............................................. 40C to 125C C RT Pin Current .........................................................1mA LT3695H ............................................ 40C to 150C SYNC Voltage ............................................................20V Storage Temperature Range ................... 65C to 150C FB Voltage (LT3695) ....................................................5V Lead Temperature (Soldering, 10 sec) .................. 300C PIN CONFIGURATION LT3695 LT3695-3.3, LT3695-5 TOP VIEW TOP VIEW PGND 1 16 BOOST PGND 1 16 BOOST 2 2 DA 15 BD DA 15 NC NC 3 14 GND NC 3 14 OUT1 4 4 17 SW 17 13 PG SW 13 OUT2 RUN/SS 5 12 NC RUN/SS 5 PGND 12 GND PGND 6 6 RT 11 FB RT 11 PG SYNC 7 10 NC SYNC 7 10 NC 8 8 V 9 V V 9 V IN C IN C MSE PACKAGE MSE PACKAGE 16-LEAD PLASTIC MSOP 16-LEAD PLASTIC MSOP = 40C/W WITH EXPOSED PAD SOLDERED = 40C/W WITH EXPOSED PAD SOLDERED JA JA = 110C/W WITHOUT EXPOSED PAD SOLDERED = 110C/W WITHOUT EXPOSED PAD SOLDERED JA JA ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LT3695EMSE PBF LT3695EMSE TRPBF 3695 16-Lead Plastic MSOP 40C to 125C LT3695IMSE PBF LT3695IMSE TRPBF 3695 16-Lead Plastic MSOP 40C to 125C LT3695HMSE PBF LT3695HMSE TRPBF 3695 16-Lead Plastic MSOP 40C to 150C LT3695EMSE-3.3 PBF LT3695EMSE-3.3 TRPBF 369533 16-Lead Plastic MSOP 40C to 125C LT3695IMSE-3.3 PBF LT3695IMSE-3.3 TRPBF 369533 16-Lead Plastic MSOP 40C to 125C LT3695HMSE-3.3 PBF LT3695HMSE-3.3 TRPBF 369533 16-Lead Plastic MSOP 40C to 150C LT3695EMSE-5 PBF LT3695EMSE-5 TRPBF 36955 16-Lead Plastic MSOP 40C to 125C LT3695IMSE-5 PBF LT3695IMSE-5 TRPBF 36955 16-Lead Plastic MSOP 40C to 125C LT3695HMSE-5 PBF LT3695HMSE-5 TRPBF 36955 16-Lead Plastic MSOP 40C to 150C Consult LTC Marketing for parts speci ed with wider operating temperature ranges. *The temperature grade is identi ed by a label on the shipping container. Consult LTC Marketing for information on non-standard lead based nish parts. For more information on lead free part marking, go to: