IR3529
Page 1 of 22 February 12, 2010
DATA SHEET
XPHASE3
TM
PHASE IC
DESCRIPTION
The IR3529 Phase IC combined with an IR XPhase3
TM
Control IC provides a full featured and flexible way to
implement power solutions for the latest high performance CPUs and ASICs. The “Control” IC provides overall
system control and interfaces with any number of “Phase” ICs which each drive and monitor a single phase of a
multiphase converter. The XPhase3
TM
architecture results in a power supply that is smaller, less expensive, and
easier to design while providing higher efficiency than conventional approaches.
The IR3529 provides two types of current sense outputs; ILL which contains average power supply current,
information which can be used for voltage positioning and ISHARE which contains average active phase current
information since current sense amplifiers of respective phases are disabled when in power savings mode. Higher
efficiency can be expected due to increased driver capability along with reduced non-overlap durations. Turbo is
included to improve load turn-on response. A SHIFT pin now communicates to the control IC a change in phase
IC on-line status resulting in controlled phase timing during PSI and Phase Shedding. The IR3529 also
implements cycle-by-cycle over current protection to resolve high repetition rate load transients.
FEATURES
• Reduced dead time
• 7V gate drivers (6A GATEL sink current, 4A GATEH sink current)
• Turbo Mode load turn-on response enhancement
• Programmable cycle-by-cycle over current limit protection
• Phase status communicated to control IC for controlled phase timing during PSI and Phase Shedding
• Power State Indicator (PSI) interface provides the capability to maximize the efficiency at light loads.
• Anti-bias circuitry
• Support converter output voltage up to 5.1 V (Limited to VCCL-1.8V)
• Loss-less inductor current sensing
• Phase delay DFF bypassed during PSI assertion mode to improve output ripple performance
• Over-current protection during PSI assertion mode operation
• Feed-forward voltage mode control
• Integrated boot-strap synchronous PFET
• Only four external components per phase
• 3 wire analog bus connects Control and Phase ICs (VID, Error Amp, Average Power Supply Current)
• 3 wire digital bus for accurate daisy-chain phase timing control without external components
• Debugging function isolates phase IC from the converter
• Self-calibration of PWM ramp, current sense amplifier, and current share amplifier
• Single-wire bidirectional average current sharing
• Small thermally enhanced 20L 4 X 4mm MLPQ package
• RoHS compliant
