LTC3675/LTC3675-1 7-Channel Configurable High Power PMIC Fea T Descrip T n Four Monolithic Synchronous Buck DC/DCs The LTC 3675/LTC3675-1 are a digitally programmable (1A/1A/500mA/500mA) high efficiency multioutput power supplies plus dual n Buck DC/DCs Can Be Paralleled to Deliver Up to string LED driver ICs optimized for high power single cell Li-Ion/Polymer applications. The DC/DCs consist of four 2 Current with a Single Inductor n synchronous buck converters (1A/1A/500mA/500mA), one Independent 1A Boost and 1A Buck-Boost DC/DCs 2 n synchronous boost DC/DC (1A), and one buck-boost DC/ Dual String I C Controlled 40V LED Driver 2 n DC (1A) all powered from a 2.7V to 5.5V input. The 40V I C Programmable Output Voltage, Operating LED driver can regulate up to 25mA of current through Mode, and Switch Node Slew Rate for All DC/DCs 2 n two LED strings with up to 10 LEDs each. The LED driver I C Read Back of DC/DC, LED Driver, Fault Status 2 n may also be configured as a general purpose high voltage I C Slave Address Options: LTC3675 = 0001001X, boost converter. LTC3675-1 = 0110100X n Maskable Interrupts to Report DC/DC, V and Die IN DC/DC enables, output voltages, switch slew rates and Temperature Faults operating modes may all be independently programmed n 2 Pushbutton ON/OFF/RESET over I C or used in standalone mode via simple I/O and n Always-On 25mA LDO power-up defaults. The buck DC/DCs may be used indepen- n Low Quiescent Current: 16A (All DC/DCs Off) dently or paralleled to achieve higher output currents with n 4mm 7mm 0.75mm 44-Lead QFN Package a shared inductor. LED enable, 60dB brightness control 2 and up/down gradation are programmed using I C. Alarm levels for low V and high die temperature may also be a T IN 2 programmed via I C with a maskable interrupt output to n High Power (5W to 10W) Single Cell Li-Ion/Polymer monitor DC/DC and system faults. Applications n Portable Industrial Applications, Handy Terminals, Pushbutton ON/OFF/RESET control and a power-on reset Portable Instruments output provide flexible and reliable power-up sequencing. n The LTC3675/LTC3675-1 are available in a low profile Multioutput Low Voltage Power Supplies (0.75mm), thermally enhanced 44-lead 4mm 7mm L, LT, LTC, LTM, Linear Technology, the Linear logo and Burst Mode are registered trademarks of Linear Technology Corporation and Hot Swap is a trademark of Linear Technology Corporation. QFN package. All other trademarks are the property of their respective owners. Typical a T SW1 0.425V TO V , 1A MAX IN 2.7V TO 5.5V V SW2 0.425V TO V , 1A MAX IN IN SW3 0.425V TO V , 500mA MAX IN 3 2 I C SW4 0.425V TO V , 500mA MAX IN LTC3675/ EN1 SW5 V IN LTC3675-1 EN2 VOUT5 V TO 5.35V, 1A MAX IN EN3 SWAB6 DIGITAL EN4 SWCD6 CONTROL ENBB VOUT6 2.65V TO 5.25V, 1A MAX IRQB LDO OUT 0.8V TO V , 25mA MAX IN RSTB V IN WAKE PBSTAT SW7 ONB PUSH BUTTON CT LED1 0.01F LED2 EXPOSED PAD UP TO 10 LEDS PER STRING 36751 TA01 36751fc 1 For more information www.linear.com/LTC3675 ion pplica ions pplica ion uresLTC3675/LTC3675-1 Table o F c T Ts Features ............................................................................................................................ 1 Applications ....................................................................................................................... 1 Typical Application ............................................................................................................... 1 Description......................................................................................................................... 1 Absolute Maximum Ratings ..................................................................................................... 3 Order Information ................................................................................................................. 3 Pin Configuration ................................................................................................................. 3 Electrical Characteristics ........................................................................................................ 4 Typical Performance Characteristics .......................................................................................... 8 Pin Functions .....................................................................................................................14 Block Diagram ....................................................................................................................16 Operation..........................................................................................................................17 Buck Switching Regulator .................................................................................................................................... 17 Buck Regulators with Combined Power Stages .................................................................................................... 17 Boost Switching Regulator ................................................................................................................................... 18 Buck-Boost Switching Regulator .......................................................................................................................... 18 LED Driver ............................................................................................................................................................ 18 Pushbutton Interface and Power-Up Power-Down Sequencing ............................................................................ 19 Power-Up and Power-Down via Pushbutton ......................................................................................................... 19 2 Power-Up and Power-Down via Enable Pin or I C ................................................................................................. 21 LED Current Programming ................................................................................................................................... 21 2 I C Interface .......................................................................................................................................................... 21 Error Condition Reporting via RSTB and IRQB Pins ............................................................................................................................................. 24 Undervoltage and Overtemperature Functionality ................................................................................................. 25 Applications Information .......................................................................................................26 Switching Regulator Output Voltage and Feedback Network................................................................................. 26 Buck Regulators ................................................................................................................................................... 26 Combined Buck Regulators .................................................................................................................................. 26 Boost Regulator .................................................................................................................................................... 27 Buck-Boost Regulator ........................................................................................................................................... 28 LED Driver ............................................................................................................................................................ 28 Operating the LED Driver As a High Voltage Boost Regulator ............................................................................... 29 Input and Output Decoupling Capacitor Selection ................................................................................................. 29 Choosing the C Capacitor ................................................................................................................................... 30 T Programming the UVOT Register ......................................................................................................................... 30 Programming the RSTB and IRQB Mask Registers .............................................................................................. 30 Status Byte Read Back ......................................................................................................................................... 31 PCB Considerations .............................................................................................................................................. 31 Typical Applications .............................................................................................................33 Package Description ............................................................................................................36 Revision History .................................................................................................................37 Typical Application ..............................................................................................................38 Related Parts .....................................................................................................................38 36751fc 2 For more information www.linear.com/LTC3675 en on