Datasheet LTC3785 (Analog Devices)
| Hersteller | Analog Devices |
| Beschreibung | 10V, High Efficiency, Synchronous, No RSENSE Buck-Boost Controller |
| Seiten / Seite | 20 / 1 — Single Inductor Architecture Allows V. IN Above,. Below or Equal to V. … |
| Dateiformat / Größe | PDF / 287 Kb |
| Dokumentensprache | Englisch |
Single Inductor Architecture Allows V. IN Above,. Below or Equal to V. OUT. 2.7V to 10V Input and Output Range
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LTC3785 10V, High Efficiency, Synchronous, No RSENSE Buck-Boost Controller FeaTures DescripTion n
Single Inductor Architecture Allows V
The LTC®3785 is a high power synchronous buck-boost
IN Above, Below or Equal to V
controller that drives all N-channel power MOSFETs from
OUT
n
2.7V to 10V Input and Output Range
input voltages above, below and equal to the output volt- n
Up to 96% Efficiency
age. With an input range of 2.7V to 10V, the LTC3785 is n
Up to 10A of Output Current
well suited for a wide variety of single or dual cell Li-Ion n
All N-channel MOSFETs, No R
or multicell alkaline/NiMH applications.
SENSE™
n True Output Disconnect During Shutdown The operating frequency can be programmed from n Programmable Current Limit and Soft-Start 100kHz to 1MHz. The soft-start time and current limit are n Optional Short-Circuit Shutdown Timer also programmable. The soft-start capacitor doubles as n Output Overvoltage and Undervoltage Protection the fault timer which can program the IC to latch off or n Programmable Frequency: 100kHz to 1MHz recycle after a determined off time. Burst Mode opera- n Selectable Burst Mode® Operation tion is user controlled and can be enabled by driving the n Available in 24-Lead (4mm × 4mm) Exposed Pad MODE pin high. QFN Package Protection features include foldback current limit, short- circuit and overvoltage protection. applicaTions L, LT, LTC, LTM, Linear Technology, the Linear logo and Burst Mode are registered trademarks of Linear Technology Corporation. No RSENSE is a trademark of Linear Technology Corporation. n Palmtop Computers All other trademarks are the property of their respective owners. n Handheld Instruments n Wireless Modems n Cellular Telephones Typical applicaTion VIN 2.7V VOUT 4.7µF TO 10V
Efficiency vs Input Voltage
VIN VCC 100 205k V I OUT = 3.3V SVIN FOSC = 500kHz V TG1 22µF SENSE 1.3k 205k 121k VBST1 95 270pF 0.22µF ILOAD = 2A FB SW1 I I SSW1 LOAD = 1A 121k 12k VDRV BG1 4.7µH EFFICIENCY (%) 90 1nF LTC3785 VC 59k VOUT RT ISVOUT 3.3V 5A MODE TG2 852.5 4 5.5 7 8.5 10 VIN (V) VBST2 3785 TA01b 0.22µF RUN/SS SW2 ILSET ISSW2 100µF 42.2k CCM BG2 1nF GND 3785 TA01a 3785fc Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Application Package Description Revision History Typical Application Related Parts
Single Inductor Architecture Allows V
The LTC®3785 is a high power synchronous buck-boost
IN Above, Below or Equal to V
controller that drives all N-channel power MOSFETs from
OUT
n
2.7V to 10V Input and Output Range
input voltages above, below and equal to the output volt- n
Up to 96% Efficiency
age. With an input range of 2.7V to 10V, the LTC3785 is n
Up to 10A of Output Current
well suited for a wide variety of single or dual cell Li-Ion n
All N-channel MOSFETs, No R
or multicell alkaline/NiMH applications.
SENSE™
n True Output Disconnect During Shutdown The operating frequency can be programmed from n Programmable Current Limit and Soft-Start 100kHz to 1MHz. The soft-start time and current limit are n Optional Short-Circuit Shutdown Timer also programmable. The soft-start capacitor doubles as n Output Overvoltage and Undervoltage Protection the fault timer which can program the IC to latch off or n Programmable Frequency: 100kHz to 1MHz recycle after a determined off time. Burst Mode opera- n Selectable Burst Mode® Operation tion is user controlled and can be enabled by driving the n Available in 24-Lead (4mm × 4mm) Exposed Pad MODE pin high. QFN Package Protection features include foldback current limit, short- circuit and overvoltage protection. applicaTions L, LT, LTC, LTM, Linear Technology, the Linear logo and Burst Mode are registered trademarks of Linear Technology Corporation. No RSENSE is a trademark of Linear Technology Corporation. n Palmtop Computers All other trademarks are the property of their respective owners. n Handheld Instruments n Wireless Modems n Cellular Telephones Typical applicaTion VIN 2.7V VOUT 4.7µF TO 10V
Efficiency vs Input Voltage
VIN VCC 100 205k V I OUT = 3.3V SVIN FOSC = 500kHz V TG1 22µF SENSE 1.3k 205k 121k VBST1 95 270pF 0.22µF ILOAD = 2A FB SW1 I I SSW1 LOAD = 1A 121k 12k VDRV BG1 4.7µH EFFICIENCY (%) 90 1nF LTC3785 VC 59k VOUT RT ISVOUT 3.3V 5A MODE TG2 852.5 4 5.5 7 8.5 10 VIN (V) VBST2 3785 TA01b 0.22µF RUN/SS SW2 ILSET ISSW2 100µF 42.2k CCM BG2 1nF GND 3785 TA01a 3785fc Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Application Package Description Revision History Typical Application Related Parts