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IR3087
DATA SHEET
XPHASETM PHASE IC WITH OPTI-PHASETM, OVP, AND OVERTEMP DETECT
DESCRIPTION
The IR3087 Phase IC combined with an IR XPhaseTM 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 XPhaseTM architecture results in a power supply that is smaller, less
expensive, and easier to design while providing higher efficiency than conventional approaches.
The IR3087 with Opti-PhaseTM is intended for applications demanding increased efficiency under medium to
light load conditions. Both gate drivers will drive low at a programmable output current threshold. This
effectively disconnects the phase from the load eliminating power losses due to switching and circulating
currents.
FEATURES
• 2.5A Average Gate Drive Current
• Loss-Less Inductor Current Sense
• Internal Inductor DCR Temperature Compensation
• Programmable Phase Delay
• Programmable Feed-Forward Voltage Mode PWM Ramp
• Sub 100ns Minimum Pulse Width supports 1MHz per-phase operation
• Current Sense Amplifier drives a single wire Average Current Share Bus
• Current Share Amplifier reduces PWM Ramp slope to ensure sharing between phases
• Body BrakingTM disables Synchronous MOSFET for improved transient response and prevents negative
output voltage at converter turn-off
• Opti-PhaseTM reduces the number of phases for improved light to medium load efficiency
• OVP comparator with 150ns response
• Programmable Phase Over-Temperature Detection
• Small thermally enhanced 20L MLPQ package
APPLICATION CIRCUIT
VGATE
12V
VRHOT
DAC
BIAS
5 Wire Analog Bus
From Control IC
RAMP
ISHARE
ROP1
ROP2
RBIASIN 20k
RCS-
CCS-
CCS+
RCS+
DBST
CBST
1 RMPIN+
2 RMPIN-
3 HOTSET
4 VRHOT
5 ISHARE
IR3087
PHASE
IC
VCCH
GATEH
PGND
GATEL
VCCL
15
14
13
12
11
L
CO
CIN
VO
CVCCL
RVCC
EA RPWMRMP
CSCOMP
CVCC
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