Datasheet LTC3769 (Analog Devices)

LTC3769 60V Low IQ Synchronous Boost Controller
FEATURES DESCRIPTION
n
Synchronous Operation for Highest Efficiency and
The LTC®3769 is a high performance single output syn-
Reduced Heat Dissipation
chronous boost converter controller that drives an all n
Wide VIN Range: 4.5V to 60V (65V Abs Max);
N-channel power MOSFET stage. Synchronous rectifica-
Operates Down to 2.3V After Start-Up
tion increases efficiency, reduces power losses and eases n
Output Voltage Up to 60V
thermal requirements, simplifying high power boost ap- n
±1% 1.200V Reference Voltage
plications. The 28µA no-load quiescent current extends n
RSENSE or Inductor DCR Current Sensing
operating run time in battery-powered systems. n
100% Duty Cycle Capability for Synchronous MOSFET
A 4.5V to 60V input supply range encompasses a wide n
Low Quiescent Current: 28μA
range of system architectures and battery chemistries. n Phase-Lockable Frequency (75kHz to 850kHz) When biased from the output of the boost converter or n Programmable Fixed Frequency (50kHz to 900kHz) another auxiliary supply, the LTC3769 can operate from an n Power Good Output Voltage Monitor input supply as low as 2.3V after start-up. The operating n Low Shutdown Current: 4µA frequency can be set within a 50kHz to 900kHz range or n Internal LDO Powers Gate Drive from VBIAS or EXTVCC synchronized to an external clock using the internal PLL. n Thermally Enhanced Low Profile 24-Pin 4mm × 4mm QFN Package and 20-Lead TSSOP Package The SS pin ramps the output voltage during start-up. The PLLIN/MODE pin selects Burst Mode® operation, pulse- skipping mode or forced continuous mode at light loads.
APPLICATIONS
L, LT, LTC, LTM, Burst Mode, OPTI-LOOP, Linear Technology and the Linear logo are registered n Industrial trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. Protected by U. S. Patents, including 5408150, 5481178, 5705919, n Automotive 5929620, 6177787, 6498466, 6580258, 6611131. n Medical n Military
TYPICAL APPLICATION 120W, 12V to 24V/5A Synchronous Boost Converter Efficiency and Power Loss vs Output Current
4mΩ 3.3µH 100 10 VIN VOUT 4.5V TO 60V 24V/5A 22µF 220µF DOWN TO 2.3V 90 VBIAS AFTER START-UP IF EFFICIENCY 1 VBIAS IS POWERED RUN SENSE+ POWER LOSS (W) 10nF V FROM V 80 OUT FOLLOWS VIN FOR VIN > 24V OUT SENSE– SS 15nF 8.66K LTC3769 BG 70 POWER 0.1 ITH LOSS 100pF TG EFFICIENCY (%) 60 SW PLLIN/MODE 0.01 0.1µF FREQ 50 BOOST OVMODE 40 0.001 0.0001 0.001 0.01 0.1 1 10 INTVCC OUTPUT CURRENT (A) ILIM 4.7µF 232k 3769 TA01b PGOOD VFB EXTVCC 12.1k GND 3769 TA01a 3769fa For more information www.linear.com/LTC3769 1 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 Applications Revision History Typical Application Related Parts