Analog Devices LT8711 | Demoboard DC2234A LT8711 Synchronous Sepic Converter

Description

Demonstration circuit 2234A is a synchronous sepicconverter featuring the LT®8711 multitopology switchingcontroller. The LT8711 is a current mode PWM DC/DCcontroller with a dual input LDO to optimize gate driverefficiency. Ultralow 15μA quiescent current in low noiseBurst Mode® operation achieves high efficiency at verylight loads and helps extend the run-time in battery poweredapplications when in standby mode. The LT8711switching frequency can be programmed either via oscillatorresistor or external clock over a 100kHz to 750kHzrange.The demo board regulates a 12V, 4A output from a 4.5Vto 40V input source, and operates at 200kHz switchingfrequency. The rated maximum load current is 4A, whilederating is necessary for certain input voltage and thermalconditions.The SYNC pin on the demo board is grounded (JP1 atBURST position) by default for low ripple high efficiencyBurst Mode operation at light load. To synchronize to anexternal clock, move JP1 to SYNC and apply the externalclock to the SYNC turret. Force continuous conductionmode can be selected by moving JP1 shunt to FCM position.

Features

• Easily Configurable as a Synchronous Buck, Boost, SEPIC, ZETA or Nonsynchronous Buck-Boost Converter
• Wide Input Range: 4.5V to 42V (VIN Can Operate to 0V, when EXTVCC > 4.5V)
• Automatic Low Noise Burst Mode® Operation
• Low IQ in Burst Mode Operation (15μA Operating)
• Input Voltage Regulation for High Impedance Source
• 100% Duty Cycle in Dropout (Buck Mode)
• 2A Gate Drivers (BG and TG) n Adjustable Soft-Start with One Capacitor
• Frequency Programmable from 100kHz to 750kHz
• Can Be Synchronized to External Clock
• Available in 20-Lead TSSOP and 20-Lead 3mm×4mm QFN Packages

Typical applications

• Solar Panel Power Converter
• Industrial Supplies
• General Purpose DC/DC Conversion
• Automotive Systems

More information

• Datasheet