The ZCC3605A is a highefficiency, monolithic synchro- nous buck regulator using a phase lockable controlledon-time constant frequency, current mode architecture. PolyPhase operationallows multiple ZCC3605A regula- torsto run out of phase while using minimalinput and output capacitance. The operating supply voltage range is from 20Vdown to 4V, making it suitable for dual, triple or quadruple lithium-ion batteryinputs as well as point of load power supply applicationsfrom a 12V or 5V rail.The operating frequency is programmable from 800kHz to 4MHzwithanexternalresistor.Thehighfrequencycapa- bilityallowstheuseofsmallsurfacemountinductors.For switching noisesensitive applications, it can be externally synchronized from 800kHz to 4MHz.The PHMODE pin allows user control ofthe phase ofthe outgoing clock signal. Theunique constant frequency/controlled on-time architectureisidealforhighstep-downratioapplicationsthat are operating at high frequency while demanding fast transient response.Two internal phase-lock loops synchronize the internal oscillator to theexternalclock and also servosthe regulator on-time to lockon toeither theinternalclockortheexternalclock ifit’spresent.
FeaTures
nHigh Efficiency: Up to 96%
n 5AOutput Current
n 4Vto 20V VIN Range
nIntegrated Power N-Channel MOSFETs
(70mΩTop and 35mΩ Bottom)
nAdjustable Frequency 800kHz to 4MHz
nPolyPhaseOperation (Up to 12 Phases)
nOutput Tracking
n0.6V ±1% Reference Accuracy
nCurrent Mode Operation for Excellent Line and Load
TransientResponse
nShutdown Mode Draws Less Than 15μA Supply Current
nZCC3605: 15V Absolute Maximum VIN
nZCC3605A: 22V Absolute Maximum VIN
n TheZCC3605A Is Pin Compatible with the
ZCC3605
nAvailable in 24-Pin (4mm ′ 4mm) QFN Package
