40V Low I, Dual, 2-Phase 100% Duty Cycle Synchronous Step-Down Controller

The LTC7805 is a high performance dual step-down synchronous DC/DC switching regulator controller that drives all N-channel power MOSFET stages. Constant frequency current mode architecture allows a phase-lockable switching frequency of up to 3MHz. The LTC7805 operates from a wide 4.5V to 40V input supply range. Power loss and supply noise are minimized by operating the two controller output stages out-of-phase.

The very low no-load quiescent current extends operating runtime 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 LTC7805 features a precision 0.8V reference and power good output indicators. The MODE pin selects among Burst Mode operation, pulse-skipping mode, or continuous inductor current mode at light loads.

The LTC7805 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.

APPLICATIONS

* Automotive and Transportation

* Industrial

* Military / Avionics

* Wide Input Voltage Range: 4.5V to 40V

* Wide Output Voltage Range: 0.8V to 40V

* Low Operating IQ

* 14μA (14V to 3.3V, Channel 1 On)

* PassThru™/100% Duty Cycle Capable

* Spread Spectrum Operation

* RSENSE or DCR Current Sensing

* Out-of-Phase Controllers Reduce Required Input Capacitance and Power Supply Induced Noise

* Programmable Fixed Frequency (100kHz to 3MHz)