High Power Synchronous Boost Controller Eliminates Heat Sink with 97% Efficiency

The LTC3787 operates from an input voltage ranging from 4.5V to 38V during start-up, maintains operation down to 2.5V after start-up and can regulate an output voltage as high as 60V. The powerful 1.2Ohm onboard N-channel MOSFET gate drivers are capable of slewing large MOSFET gates quickly. The device's current mode architecture, clock output and phase modulation enables easy paralleling of multiple devices for up to 12 phase operation. The LTC3787 has a phase-lockable frequency from 75kHz to 850kHz or a selectable fixed frequency from 50kHz to 900kHz. In applications where the input voltage exceeds the regulated output voltage, the LTC3787 keeps the synchronous MOSFET on continuously so that the output voltage follows the input voltage with minimal power loss. In addition, this device features adjustable cycle-by-cycle current limit and can use a sense resistor or monitor the voltage drop across the inductor (DCR) for current sensing. Furthermore, the LTC3787 has adjustable soft-start, a power good output and maintains +1% reference voltage accuracy over an operating junction temperature range of
-40°C to 125°C.

The LTC3787 is available in SSOP-28 and 4mm x 5mm QFN-28 packages. The 1,000-piece price starts at $4.12 each. For more information, visit www.linear.com/3787.


Summary of Features: LTC3787

* Up to 97% Efficiency
* Eliminates Heat Sink in Medium to High Power Boost Converters
* Up to 60V VOUT Operation
* Wide VIN Ranging from 4.5V to 38V, Maintains Operation down to 2.5V after Start-Up
* Low 135uA Quiescent Current
* Powerful 1.2 Ohm Gate Drivers
* 100% Duty Cycle Capability for Synchronous MOSFET
* Phase Lockable Frequency from 75kHz to 850kHz
* Programmable Fixed Frequency from 50kHz to 900kHz
* RSENSE or Inductor DCR Current Sensing
* Current Mode Control
* +1% Reference Voltage Accuracy over -40°C to +125°C
* Programmable Soft-Start
* Phase Modulation for up to 12 Phases
* Power Good Output