FEATURES * 3.6V to 15V Input Voltage Range * 3A Output Current per Channel * Up to 95% Efficiency * Low Duty Cycle Operation: 5% at 2.25MHz * Selectable 0°/180° Phase Shift Between Channels * Adjustable Switching Frequency: 500kHz to 4MHz * External Frequency Synchronization * Current Mode Operation for ExcellentLine andLoad Transient Response * 0.6V Reference Allows Low Output Voltages * User Selectable Burst Mode® Operation or Forced C ontinuous Operation * Output Voltage Tracking and Soft-Start Capability * Short-Circuit Protected * Overvoltage Input and Overtemperature Protection * Low Power 2.5V Linear Regulator Output * Power Good Status Outputs * Available in (4mm × 5mm) QFN-28 and 28-Lead TSSOP Packages DESCRIPTION TheZCC3633isahighefficiency,dual-channelmonolithic synchronous buck regulator using a controlled on-time, current mode architecture, with phase lockable switching frequency. The two channels can run 180° out of phase, which relaxes the requirementsfor input and output ca-pacitance.Theoperatingsupplyvoltagerangeisfrom3.6V to 15V,making it suitable for dual cell lithium-ion batteries as well as point of load power supply applications froma 12V or 5V supply Theoperatingfrequencyisprogrammableandsynchroniz-able from 500kHz to 4MHz with an external resistor. The high frequencycapability allows the use of small surface mount inductors andcapacitors. The unique constant frequency/controlled on-time architecture is ideal for high step-downratioapplicationsthatoperateathighfrequency whiledemandingfasttransientresponse.Aninternalphase lock loop servos the on-time ofthe internal one-shottimer to match the frequency of the internal clock or an applied external clock.