IR3088A_05 Datasheet, PDF (1/33 Pages) International Rectifier – XPHASETM PHASE IC WITH FAULT AND OVERTEMP DETECT

IR3088A
DATA SHEET
XPHASE^TM PHASE IC WITH FAULT AND OVERTEMP DETECT
DESCRIPTION
The IR3088A 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 IR3088A is intended for the following application conditions;
• Excessive impedance between converter and load
• Output voltage exceeding the control IC reference/VID voltage is desired
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
• Phase Fault Detection
• Programmable Phase Over-Temperature Detection
• Control FET driver’s 25V input voltage capability simplifies boot-strap supply design
• Small thermally enhanced 20L MLPQ package
APPLICATION CIRCUIT
VGATE
12V
PHASE FAULT
VRHOT
DAC
BIAS
5 Wire Analog Bus
RAMP
From Control IC
ISHARE
EA
RCS-
RBIASIN 20k
CCS-
CCS+
RCS+
DBST
CBST
CIN
1
RMPIN+
15
VCCH
2 _{RMPIN- IR3088A GATEH} 14
L
3
HOTSET
PHASE
13
PGND
IC ⁴ VRHOT
GATEL ¹²
CO
5 _ISHARE
VCCL ¹¹
CSCOMP
RVCC
RPWMRMP
CVCCL
CVCC
VO
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1/15/05