IR3087PBF Datasheet, PDF (1/35 Pages) International Rectifier – XPHASETM PHASE IC WITH OPTI-PHASETM, OVP, AND OVERTEMP DETECT

IR3087PBF
DATA SHEET
XPHASE^TM PHASE IC WITH OPTI-PHASE^TM, OVP, AND OVERTEMP DETECT
DESCRIPTION
The IR3087 Phase IC combined with an IR XPhase^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 XPhase^TM 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-Phase^TM 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 Braking^TM disables Synchronous MOSFET for improved transient response and prevents negative
output voltage at converter turn-off
• Opti-Phase^TM 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
RAMP
From Control IC
ISHARE
EA
ROP1
ROP2
RBIASIN 20k
RCS-
CCS-
CCS+
RCS+
DBST
CBST
CIN
1 _RMPIN+
VCCH ¹⁵
2 _{RMPIN- IR3087 GATEH} 14
L
3 _{HOTSET PHASE}
PGND ¹³
IC 4
VRHOT
12
GATEL
CO
5 _ISHARE
VCCL ¹¹
CSCOMP
RVCC
RPWMRMP
CVCCL
CVCC
VO
Page 1 of 35
1/31/05