40V, 3MHz, Triple-Output Buck/Buck/Boost Synchronous Controller
The LTC®7818 from Analog Devices 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 LTC7818 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 LTC7818 can operate from an input supply as low as 1V after start-up. This dc-dc switching regulator controller is designed for use in automotive and transportation systems, industrial equipment and military/avionics designs.
The very low no-load quiescent current extends operating run time in battery powered systems. OPTI-LOOP® compensation allows the transient response to be optimized over a wide range of output capacitance and ESR values.
The LTC7818 features a precision 0.8V reference for the bucks, 1.2V reference for the boost and a power good output indicator.
The LTC7818 additionally features spread spectrum operation which significantly reduces the peak radiated and conducted noise on both the input and output supplies, making it easier to comply with electromagnetic interference (EMI) standards.
Summary of 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
- Spread Spectrum Operation
- RSENSE or DCR Current Sensing
- 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
- Boost Channel Current Monitor Output
- Low Shutdown IQ: 1.5µA
- Small 40-Lead 6mm × 6mm QFN Package