Datasheet LTC3786 (Analog Devices)

FabricanteAnalog Devices
DescripciónLow IQ Synchronous Boost Controller
Páginas / Página34 / 1 — Synchronous Operation For Highest Efficiency and. Reduced Heat …
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Synchronous Operation For Highest Efficiency and. Reduced Heat Dissipation. Wide VIN Range: 4.5V to 38V (40V Abs Max) and

Datasheet LTC3786 Analog Devices

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LTC3786 Low IQ Synchronous Boost Controller FEATURES DESCRIPTION n
Synchronous Operation For Highest Efficiency and
The LTC®3786 is a high performance synchronous boost
Reduced Heat Dissipation
converter controller that drives all N-channel power n
Wide VIN Range: 4.5V to 38V (40V Abs Max) and
MOSFETs. Synchronous rectification increases efficiency,
Operates Down to 2.5V After Start-Up
reduces power losses and eases thermal requirements, n
Output Voltages Up to 60V
allowing the LTC3786 to be used in high power boost n
±1% 1.2V Reference Voltage
applications. n
RSENSE or Inductor DCR Current Sensing
A 4.5V to 38V input supply range encompasses a wide n
100% Duty Cycle Capability for Synchronous MOSFET
range of system architectures and battery chemistries. n
Low Quiescent Current: 55µA
When biased from the output of the boost converter or n Phase-Lockable Frequency (75kHz to 850kHz) another auxiliary supply, the LTC3786 can operate from n Programmable Fixed Frequency (50kHz to 900kHz) an input supply as low as 2.5V after start-up. The 55µA n Adjustable Output Voltage Soft-Start no-load quiescent current extends operating run time in n Power Good Output Voltage Monitor battery-powered systems. n Low Shutdown Current IQ: <8µA n Internal 5.4V LDO for Gate Drive Supply The operating frequency can be set for a 50kHz to 900kHz n Thermally Enhanced 16-Pin 3mm × 3mm QFN and range or synchronized to an external clock using the MSOP Packages internal PLL. The LTC3786 also features a precision 1.2V reference and a power good output indicator. The SS pin APPLICATIONS ramps the output voltage during start-up. The PLLIN/MODE pin selects among Burst Mode® operation, pulse-skipping n Industrial and Automotive Power Supplies mode or continuous inductor current mode at light loads. n Automotive Start-Stop Systems n Medical Devices All registered trademarks and trademarks are the property of their respective owners. n High Voltage Battery-Powered Systems TYPICAL APPLICATION
12V to 24V/5A Synchronous Boost Converter Efficiency and Power Loss
VIN 4.5V TO 24V
vs Load Current
VBIAS 100 10000 SENSE+ 90 LTC3786 4mΩ 220µF 80 BURST 1000 PGOOD SENSE– EFFICIENCY BURST POWER LOSS (mW) PLLIN/MODE 70 LOSS 3.3µH RUN 60 100 FREQ TG 0.1µF 50 VOUT SS SW 24V 40 10 15nF 0.1µF 220µF 5A EFFICIENCY (%) 8.66k 30 ITH BOOST 220pF VIN = 12V BG 20 1 VOUT = 24V 12.1k 10 Burst Mode OPERATION VFB INTV FIGURE 8 CIRCUIT CC 4.7µF 0 0.1 0.00001 0.0001 0.001 0.01 0.1 1 10 232k GND OUTPUT CURRENT (A) 3786 TA01a 3786 TA01b 3786fc For more information www.linear.com/LTC3786 1