Linear Technology LTC3118 Manuals

LTC3118 1 3118fa For more information www.linear.com/LTC3118 Typical applicaTion FeaTures DescripTion 18V, 2A Buck-Boost DC/DC Converter with Low Loss Dual Input PowerPath The LTC®3118 is a dual-input, wide voltage range syn- chronous buck-boost DC/DC converter with an intelligent, integrated, low loss PowerPath control. The unique power switch architecture provides efficient operation from either input source to a programmable output voltage above, below or equal to the input. Voltage capability of up to 18V provides flexibility and voltage margin for a wide variety of applications and power sources. The LTC3118 uses a low noise, current mode architecture with a fixed 1.2MHz PWM mode frequency that minimizes the solution footprint. For high efficiency at light loads, automatic Burst Mode operation can be selected consum- ing only 50µA of quiescent current in sleep. System level features include ideal diode or VIN priority modes, VIN and VOUT power good indicators, accurate RUN comparators to program independent UVLO thresholds, and output disconnect in shutdown. Other features include 2µA shutdown current, short-circuit protection, soft-start, current limit and thermal overload protection. The LTC3118 is offered in thermally enhanced 24-lead 4mm × 5mm QFN and 28-lead TSSOP packages. applicaTions n Integrated High Efficiency Dual Input PowerPath™ Plus Buck-Boost DC/DC Converter n Ideal Diode or Priority VIN Select Modes n VIN1 and VIN2 Range: 2.2V to 18V n VOUT Range: 2V to 18V n Either VIN Can Be Above, Below or Equal to VOUT n Generates 5V at 2A for VIN > 6V n 1.2MHz Low Noise Fixed Frequency Operation n Current Mode Control n All Internal N-Channel MOSFETs n Pin-Selectable PWM or Burst Mode® Operation n Accurate, Independent RUN Pin Thresholds n Up to 94% Efficiency n VIN and VOUT Power Good Indicators n IQ of 50µA in Sleep, 2µA in Shutdown n 4mm × 5mm 24-Lead QFN or 28-Lead TSSOP Packages n Systems with Multiple Input Sources n Back Up Power Systems n Wall Adapter or Li-Ion(s) Input to 5VOUT n Battery or Super Capacitor Input for Reserve Power n Replace Diode-OR Designs with Higher Efficiency, Flexibility and Performance L, LT, LTC, LTM, Linear Technology, the Linear logo and Burst Mode are registered trademarks and PowerPath and ThinSOT are trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. Protected by U.S. Patents, including 7709976. CONTROL SIGNALS 3.3µH 0.1µF 0.1µF 400k 40.2k 47nF 22µF 22µF 100µF INDICATORS 4.7µF 10nF 22pF BST1 BST2 VIN1 VIN2 VIN1 VIN2 SW1 SW2 3118 TA01a CM1 47nF CM2 CP1 VOUT VOUT 5V VC V1GD FB V2GD PGD MODE SEL RUN1 RUN2 CN1 10nF CN2 CP2 PGND VCC GND LTC3118 1.8nF 100k 100µs/DIV 3118 TA01b 5VOUT AC-COUPLED 500mV/DIV SW1 10V/DIV SEL 5V/DIV SELECT VIN2 SELECT VIN1 VIN1 = 5V, VIN2 = 12V, VOUT = 5V AT 1A Input Switchover Response

1 dc2045af DEMO MANUAL DC2045A Description LTC3118EUFD 18V, 2A Buck-Boost DC/DC Converter with Low-Loss Dual Power Path Demonstration Circuit 2045A featuring the LTC3118 is a dual input fixed frequency synchronous buck-boost con- verter with an intelligent integrated low-loss Power-Path™. The unique all N-Channel architecture provides efficient operation from either input source to a programmable output voltage above, below or equal to the input. Volt- age capability of up to 18V provides flexibility and voltage margin for a variety of applications and power sources. The LTC3118 uses a low noise, current mode architecture with a fixed 1.2MHz PWM mode frequency that minimizes the solution footprint. For high efficiency at light loads, automatic Burst Mode™ operation can be selected con- suming only 50μA of quiescent current in sleep. Typical efficiencies for both Burst Mode and fixed frequency are shown in Figure 1. JP2 in the FIXED FREQ position results in low output ripple but also lower efficiency at light loads. Moving the JP2 position to AUTOBURST enables Burst Mode operation which improves efficiency at light load. L, LT, LTC, LTM, Burst Mode, Linear Technology and the Linear logo are registered trademarks and PowerPath is a trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. Performance Summary System level features include selectable IDEAL DIODE Mode (shown in Figure 2) or PRIORITY mode operation (shown in Figure 3) The system can be monitored through V1GD, V2GD and PGD (power good) indicators There are accurate RUN comparators to program independent UVLO thresholds, and output disconnect in shutdown. Other features include 2μA shutdown current, short-circuit protection, soft-start, inductor current limit and thermal overload protection. The DC2045A circuit has excellent transient load response in both fixed frequency and automatic Burst Mode opera- tion as shown in Figures 4 and 5. The LTC3118 data sheet has detailed information about the operation, specifications, and applications of the part. The data sheet should be read in conjunction with this Quick Start Guide. Design files for this circuit board are available at http://www.linear.com/demo/DC2045A Specifications are at TA = 25°C Input Voltage Range: 2.5V to 18.0V VOUT 5.0V IOUT 2.0A for VIN > 5.0V