LTC3112 15V, 2.5A Synchronous Buck-Boost DC/DC Converter FEATURES DESCRIPTION n Regulated Output with V Above, Below or Equal to V The LTC 3112 is a fixed frequency synchronous buck-boost IN OUT n 2.7V to 15V Input Voltage Range DC/DC converter with an extended input and output range. n 2.5V to 14V Output Voltage Range The unique 4-switch, single inductor architecture provides n 2.5A Continuous Output Current: V 5V, low noise and seamless operation from input voltages IN V = 5V, PWM Mode above, below or equal to the output voltage. OUT n Output Current Monitor With an input range of 2.7V to 15V, the LTC3112 is well- n Up to 95% Efficiency suited for a wide variety of single or multiple cell battery, n 750kHz Switching Frequency, Synchronizable backup capacitor or wall adapter source applications. Low Between 300kHz and 1.5MHz R internal N-Channel MOSFET switches provide DS(ON) n Internal N-Channel MOSFETs highly efficient operation in applications with higher load n Selectable Burst Mode Operation, I = 50A Q current requirements. n Shutdown Current < 1A n The LTC3112 features selectable PWM or Burst Mode Overvoltage Protection n operation, an easily synchronized oscillator and output Output Disconnect in Shutdown n disconnect in shutdown. An output current monitor circuit Internal Soft-Start n allows the load current to be controlled or measured. Other Small, Thermally Enhanced 16-Lead (4mm 5mm features include <1A shutdown current, short circuit 0.75mm) DFN and 20-Lead TSSOP Package protection, soft-start, current limit and thermal shutdown. APPLICATIONS The LTC3112 is offered in both a 16-pin (4mm 5mm n 3.3V or 5V from 1, 2 or 3 Li-Ion, Backup Capacitor Stack 0.75mm) DFN and 20-pin TSSOP packages. n Hand Held Inventory Terminals L, LT, LTC, LTM, Linear Technology Burst Mode, LTSpice and the Linear logo are registered trademarks and No R and PowerPath are trademarks of Linear Technology Corporation. n SENSE RF Transmitters All other trademarks are the property of their respective owners. Protected by U.S. Patents, n including 5481178. 12V Synchronous Boost Converter n Multiple Power Input Systems n LED Lighting with Current Regulation n 12V Lead Acid Battery to 12V TYPICAL APPLICATION Efficiency at 5V OUT 100 5V, 750kHz Wide Input Voltage Range Buck-Boost Regulator PWM 90 4.7H BURST 80 0.1F 0.1F SW1 SW2 70 BST1 BST2 5V/2.5A, V > 5V 2.7V TO 15V IN V V V V IN OUT OUT IN 33k 60 680pF 47pF LTC3112 V COMP CC 845k 10k 22pF BURST PWM PWM/SYNC 50 FB 10F OFF ON TO ADC RUN I 2.7V OUT IN 40 1V PER AMP 47F 5.0V IN GND OVP 12V 1F 100pF 42.2k 158k IN 30 0.0001 0.001 0.01 0.1 1 3112 TA01 LOAD CURRENT (A) 3112 TA02 3112fd 1 For more information www.linear.com/LTC3112 EFFICIENCY (%)LTC3112 ABSOLUTE MAXIMUM RATINGS (Notes 1, 3) RUN Voltage............................................... 0.3V to 16V V Voltage ................................................. 0.3V to 16V IN PWM/SYNC, V , I Voltage ....................0.3V to 6V CC OUT V Voltage .............................................. 0.3V to 15V OUT FB, COMP, OVP Voltage ...............................0.3V to 6V SW1 Voltage (Note 4) ................... 0.3V to (V + 0.3V) IN Operating Junction Temperature Range (Notes 2, 6) SW2 Voltage (Note 4) ................ 0.3V to (V + 0.3V) OUT ............................................................... 55C to 150C V Voltage ...................(V 0.3V) to (V + 6V) BST1 SW1 SW1 Storage Temperature Range ..................65C to 150C V Voltage ...................(V 0.3V) to (V + 6V) BST2 SW2 SW2 Lead Temperature (Soldering, 10sec) TSSOP .......300C PIN CONFIGURATION TOP VIEW TOP VIEW GND 1 GND 20 COMP 2 PWM/SYNC COMP 1 16 PWM/SYNC 19 FB 3 V FB 2 15 V 18 CC CC OVP 4 BST1 OVP 3 14 BST1 17 V 5 SW1 V 4 13 SW1 16 IN IN 17 21 GND GND V 6 SW1 V 5 12 SW1 15 IN IN RUN 6 11 BST2 RUN 7 BST2 14 I 7 10 SW2 I 8 SW2 13 OUT OUT V 8 9 SW2 V 9 SW2 12 OUT OUT GND 10 GND 11 DHD16 PACKAGE 16-LEAD (5mm 4mm) PLASTIC DFN FE PACKAGE T =150 C, q = 43C/W, q = 4C/W 20-LEAD PLASTIC TSSOP JMAX JA JC EXPOSED PAD (PIN 17) IS GND, MUST BE SOLDERED TO PCB T = 150C, q = 38C/W, q = 4C/W JMAX JA JC EXPOSED PAD (PIN 21) IS GND, MUST BE SOLDERED TO PCB ORDER INFORMATION