LTC7802 40V Low IQ, 3MHz Dual, 2-Phase Synchronous Step-Down Controller with Spread Spectrum FEATURESDESCRIPTION n Wide Input Voltage Range: 4.5V to 40V The LTC®7802 is a high performance dual step-down n Wide Output Voltage Range: 0.8V to 99% • VIN synchronous DC/DC switching regulator controller that n Low Operating IQ: 14μA (14V to 3.3V, Channel 1 On) drives all N-channel power MOSFET stages. Constant fre- n Spread Spectrum Operation quency current mode architecture al ows a phase-lockable n RSENSE or DCR Current Sensing switching frequency of up to 3MHz. The LTC7802 oper- n Out-of-Phase Controllers Reduce Required Input ates from a wide 4.5V to 40V input supply range. Power Capacitance and Power Supply Induced Noise loss and supply noise are minimized by operating the two n Programmable Fixed Frequency (100kHz to 3MHz) controller output stages out-of-phase. n Phase-Lockable Frequency (100kHz to 3MHz) The very low no-load quiescent current extends oper- n Selectable Continuous, Pulse-Skipping, or Low ating runtime in battery powered systems. OPTI-LOOP Ripple, Burst Mode® Operation at Light Loads compensation allows the transient response to be opti- n Very Low Dropout Operation: 99% Duty Cycle mized over a wide range of output capacitance and ESR n Power Good Output Voltage Monitors values. The LTC7802 features a precision 0.8V reference n Output Overvoltage Protection and power good output indicators. The MODE pin selects n Internal LDO Powers Gate Drive from VIN or EXTVCC among Burst Mode operation, pulse-skipping mode, or n Low Shutdown IQ: 1.5μA continuous inductor current mode at light loads. n Small 28-Lead 4mm × 5mm QFN Package The LTC7802 additionally features spread spectrum oper- ation which significantly reduces the peak radiated and conducted noise on both the input and output supplies, APPLICATIONS making it easier to comply with electromagnetic interfer- n Automotive and Transportation ence (EMI) standards. n Industrial All registered trademarks and trademarks are the property of their respective owners. n Military/Avionics TYPICAL APPLICATION V INTV IN CC 4.5V TO 40V 4.7µF RUN1 VIN RUN2 INTVCC BOOST1 BOOST2 TG1 TG2 0.9µH 0.1µF 0.1µF 1.8µH SW1 SW2 LTC7802 BG1 BG2 SENSE1+ SENSE2+ 2mΩ 3mΩ VOUT1 SENSE1– SENSE2– VOUT2 3.3V/12A EXTVCC 5V/10A 210k 357k 330µF 220µF VFB1 VFB2 ITH1 ITH2 68.1k TRACK/SS1 TRACK/SS2 68.1k MODE PLLIN/SPREAD 0.1µF 0.1µF FREQ GND 7802 TA01a Rev. 0 Document Feedback For more information www.analog.com 1 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Order Information Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Functional Diagram Operation Applications Information Typical Applications Package Description Typical Application Related Parts
