IRU3146CF

Data Sheet No.PD 94702 IRU3146 DUAL SYNCHRONOUS PWM CONTROLLER WITH CURRENT SHARING CIRCUITRY AND AUTO-RESTART FEATURES Dual Synchronous Controller with 180 out-of-phase Configurable to 2-Independent Outputs or 2-Phase Single Output Current Sharing Using Inductor's DCR Current Limit using MOSFET's RDS(ON) Hiccup/Latched Current Limit Latched Over-Voltage Protection Vcc from 4.5V to 16V Input Programmable Switching Frequency up to 500KHz Two Independent Soft-Starts/ Shutdowns 0.8V Precision Reference Voltage Available Power Good Output External Frequency Synchronization DESCRIPTION The IRU3146 IC combines a Dual synchronous Buck controller, providing a cost-effective, high performance and flexible solution. The IRU3146 can configured as 2independent or as 2-phase controller. The 2-phase configuration is ideal for high current applications. The IRU3146 features 180 out of phase operation which reduces the required input/output capacitance and results to few number of capacitor quantity. Other key features offered by this device include two independent programmable soft starts, programmable switching frequency up to 500KHz per phase, under voltage lockout function. The current limit is provided by sensing the lower MOSFET's on-resistance for optimum cost and performance. 2-Phase Power Supply Graphic Card DDR Memory Applications D1 C12 APPLICATIONS Embedded Computer Systems Telecom Systems Point of Load Power Architectures 12V C11 C3 C4 C13 Q2 C14 L3 VCL VcH1 VOUT3 VcH2 Vcc HDrv1 OCSet1 Hiccup Sync VREF LDrv1 PGnd1 VP2 C5 R1 Q3 R5 C15 R10 1.8V @ 30A C16 R2 C8 R3 Rt U1 IRU3146 D2 BAT54A VSEN1 VSEN2 Fb1 Fb2 C17 R11 R7 Comp1 R9 C18 L4 R8 C9 R4 Comp2 HDrv2 OCSet2 R6 Q4 Q5 PGood C10 PGood SS1 / SD SS2 / SD LDrv2 PGnd2 Gnd Figure 1 - Typical application of IRU3146 in 2-phase configuration with inductor current sensing PACKAGE ORDER INFORMATION DEVICE IRU3146CF Rev. 1.1 6/25/04 PACKAGE 28-Pin TSSOP (F) www.irf.com 1 IRU3146 ABSOLUTE MAXIMUM RATINGS Vcc, VCL Supply Voltage .............................................. -0.5V To 16V VcH1 and VcH2 Supply Voltage ................................ -0.5V To 25V PGOOD................. ................................................... -0.5V To 16V Storage Temperature Range ...................................... -40°C To 125°C Operating Junction Temperature Range ..................... -40°C To 125°C Caution: Stresses above those listed in Absolute Maximum Ratings" may cause permanent damage to the device. PACKAGE INFORMATION 28-PIN TSSOP (F) PGood 1 VCC 2 VOUT3 3 Rt 4 VSEN2 5 Fb2 6 Comp2 7 SS2 / SD 8 OCSet2 9 VcH2 10 HDrv2 11 PGnd2 12 LDrv2 13 VCL 14 28 Gnd 27 VREF 26 VP2 25 Hiccup 24 Sync 23 VSEN1 22 Fb1 21 Comp1 20 SS1 / SD 19 OCSet1 18 VcH1 17 HDrv1 16 PGnd1 15 LDrv1 θJA = 84°C/W ELECTRICAL SPECIFICATIONS Unless otherwise specified, these specifications apply over Vcc=12V, VcH1=VcH2=VCL=12V and TA=0 to 70°C. Typical values refer to TA=25°C. Low duty cycle pulse testing is used which keeps junction and case temperatures equal to the ambient temperature. PARAMETER Reference Voltage Section Reference Voltage Voltage Line Regulation UVLO Section UVLO Threshold - Vcc UVLO Hysteresis - Vcc UVLO Threshold - VcH1 UVLO Hysteresis - VcH1 UVLO Threshold - VcH2 UVLO Hysteresis - VcH2 Supply Current Section Vcc Dynamic Supply Current VcH1 & VcH2 Dynamic Current VCL Dynamic Supply Current Vcc Static Supply Current VcH1/VcH2 Static Current VCL Static Supply Current SYM VREF LREG TEST CONDITION MIN 0.789 5