Analog Devices LTC7817

Description

The LTCR7817 is a high performance triple output (buck/ buck/boost) synchronous DC/DC switching regulator controller that drives all N-channel power MOSFET stages. Its constant frequency current mode architecture allows a phase-lockable switching frequency of up to 3MHz. The LTC7817 operates from a wide 4.5V to 40V input supply range. When biased from the output of the boost converter or another auxiliary supply, the LTC7817 can operate from an input supply as low as 1V after start-up. The very low no-load quiescent current extends operating run time in battery powered systems. OPTI-LOOPR compensation allows the transient response to be optimized over a wide range of output capacitance and ESR values. The LTC7817 features a precision 0.8V reference for the bucks, 1.2V reference for the boost and a power good output indicator.

Features

• Dual Buck Plus Single Boost Synchronous Controllers
• Low Operating IQ: 14μA (14V to 3.3V, Channel 1 On)
• Outputs Remain in Regulation Through Cold Crank Down to 1V Input Supply Voltage
• Wide Bias Input Voltage Range: 4.5V to 40V
• Buck and Boost Output Voltages up to 40V
• RSENSE or DCR Current Sensing
• Pass-Thru™ Operation: 100% Duty Cycle for Boost Synchronous MOSFET
• Programmable Fixed Frequency (100kHz to 3MHz)
• Phase-Lockable Frequency (100kHz to 3MHz)
• Selectable Continuous, Pulse-Skipping, or Low Ripple Burst Mode Operation at Light Loads
• Very Low Buck Dropout Operation: 99% Duty Cycle
• Low Shutdown IQ: 1.5μA
• Small 38-Lead 5mm × 7mm QFN Package
• AEC-Q100 Automotive Qualification in Process

Typical applications

• Military/Avionics
• Industrial
• Automotive and Transportation

More information

• Datasheet
• IC product information