LINEAR TECHNOLOGY LTC3780 User's Manual
Summary
The LTC3780 is a high-efficiency, synchronous buck-boost controller designed for robust DC power management in demanding environments. Utilizing advanced single inductor technology, it regulates voltage across extremely wide input and output ranges (4V to 36V). This manual provides comprehensive technical specifications, operational modes (including Burst Mode and Forced Continuous), and detailed application circuits. It is the ideal solution for high-power battery devices, automotive systems, telecom infrastructure, and industrial control requiring superior performance and reliability in power distribution.
Page 1 Text Content
LTC3780
POW ER LOSS (W
High Efficiency, Synchronous, 4-Switch Buck-Boost Controller
FEATURES DESCRIPTIO Single Inductor Architecture Allows VIN Above, The LTC®3780 is a high performance buck-boost switch- Below or Equal to VOUT ing regulator controller that operates from input voltages Wide VIN Range: 4V to 36V Operation above, below or equal to the output voltage. The constant Synchronous Rectification: Up to 98% Efficiency frequency current mode architecture allows a phase- Current Mode Control lockable frequency of up to 400k Hz. With a wide 4V to 30V ±1% Output Voltage Accuracy: 0.8V < VOUT < 30V (36V maximum) input and output range and seamless Phase-Lockable Fixed Frequency: 200k Hz to 400k Hz transfers between operating modes, the LTC3780 is ideal Power Good Output Voltage Monitor for automotive, telecom and battery-powered systems. Internal LDO for MOSFET Supply
The operating mode of the controller is determined through
Quad N-Channel MOSFET Synchronous Drive
the FCB pin. For boost operation, the FCB mode pin can
VOUT Disconnected from VIN During Shutdown
select among Burst Mode® operation, Discontinuous mode
Adjustable Soft-Start Current Ramping
and Forced Continuous mode. During buck operation, the
Foldback Output Current Limiting
FCB mode pin can select among Skip-Cycle mode, Discon-
Selectable Low Current Modes
tinuous mode and Forced Continuous mode. Burst Mode
Output Overvoltage Protection
operation and Skip-Cycle mode provide high efficiency
Available in 24-Lead SSOP and Exposed Pad
operation at light loads while Forced Continuous mode
(5mm × 5mm) 32-Lead QFN Packages
and Discontinuous mode operate at a constant frequency.
EF FI CI EN CY
APPLICATIO S Fault protection is provided by an output overvoltage comparator and internal foldback current limiting. A Power
Automotive Systems
Good output pin indicates when the output is within 7.5%
Telecom Systems
of its designed set point.
DC Power Distribution Systems
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
High Power Battery-Operated Devices Burst Mode is a registered trademark of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
Industrial Control
Protected by U.S. Patents including 5481178, 6304066, 5929620, 5408150, 6580258, patent pending on current mode architecture and protection
TYPICAL APPLICATIO
High Efficiency Buck-Boost Converter
5V TO 32V 22µF 100µF
330µF 5A+ Efficiency and Power Loss
CER CER VOUT = 12V, ILOAD = 5A
VIN PGOOD INTVCC CER
TG2 TG1
BOOST2 BOOST1
SW2 SW1
LTC3780
BG2 BG1 PLLIN
RUN ON/OFF
SS 1%
20k 0.1µF VOSENSE
SGND FCB 7.5k SENSE+ SENSE– PGND
VIN (V)
4.7µH 3780 TA01b
3780 TA01
3780fb
Page Summary Contents For LINEAR TECHNOLOGY LTC3780 User's Manual
Manual Details
| Brand | Linear |
|---|---|
| Pages | 28 |
| File Size | 467.90 KB |
| Published | June 03, 2026 |
Enter the captcha to get the download link:
Frequently Asked Questions
What is the wide operational voltage range of the LTC3780?
The controller supports a wide V range, operating from 4V to 36V for both input and output voltages.
How can I monitor if the power rails are stable during operation?
Use the Power Good (PGOOD) output pin, which indicates when the voltage is within 7.5% of its designed set point.
What forms of protection are available against system faults?
It provides protection via an output overvoltage comparator and internal foldback current limiting feature.
Which operating modes optimize efficiency at low loads?
Selectable low current modes, such as Burst Mode or Discontinuous mode, help maintain high efficiency when operating at light loads.