IR3621PBF

Data Sheet No.PD60231 revA IR3621 & (PbF) 2-PHASE / DUAL SYNCHRONOUS PWM CONTROLLER WITH OSCILLATOR SYNCHRONIZATION AND PRE-BIAS STARTUP FEATURES Dual Synchronous Controller with 180! Out of Phase Operation Configurable to 2-Independent Outputs or Current Share Single Output Voltage Mode Control Current Sharing Using Inductor's DCR Selectable Hiccup or Latched Current Limit using MOSFET's RDS(on) sensing Latched Over-Voltage Protection Pre-Bias Start Up Programmable Switching Frequency up to 500KHz Two Independent Soft-Starts/Shutdowns Precision Reference Voltage 0.8V Power Good Output External Frequency Synchronization Thermal Protection DESCRIPTION The IR3621 IC combines a dual synchronous buck controller and drivers, providing a cost-effective, high performance and flexible solution. The IR3621 operates in 2-Phase mode to produce either 2-independent output voltages or current share single output for high current application. The 180! out-of-phase operation allows the reduction of input and output capacitance. Other key features include two independently programmable soft-start functions to allow system level sequencing of output voltages in various configurations. The pre-bias protection feature prevents the discharge of the output voltage and possible damage to the load during start-up when a preexisting voltage is present at the output. Programmable switching frequency up to 500KHz per phase allows flexibility to tune the operation of the IC to meet system level requirements, and synchronization allows the simplification of system level filter design. Protection features such as selectable hiccup or latched current limit, and under voltage lock-out are provided to give required system level security in the event of a fault condition. APPLICATIONS Embedded Networking & Telecom Systems Distributed Point-of-Load Power Architectures 2-Phase Power Supply Graphics Card DDR Memory Applications Vin Vin Rt Comp1 HDrv1 OCSet1 LDrv1 PGnd1 Rt Comp1 HDrv1 OCSet1 LDrv1 PGnd1 Vout1 Comp2 SS1 / SD SS2 / SD Gnd IR3621 HDrv2 OCSet2 LDrv2 PGnd2 Vin Vout Comp2 SS1 / SD SS2 / SD IR3621 HDrv2 OCSet2 LDrv2 Vin Vout2 Gnd PGnd2 Current share, single output configuration 2-independent output voltage configuration Figure 1 - Typical application of IR3621 in current share single output and 2-independent output voltage configuration ORDERING INFORMATION PKG DESIG M M F F PART NUMBER IR3621M IR3621MTR IR3621F IR3621FTR LEADFREE PART NUMBER IR3621MPbF IR3621MTRPbF N/A N/A PIN COUNT 32 32 28 28 www.irf.com PARTS PER TUBE 73 -----50 -----PARTS PER REEL -----6000 -----2500 T&R Orientation Fig A 1 IR3621 & (PbF) ABSOLUTE MAXIMUM RATINGS Vcc, VCL Supply Voltage ........................................... VcH1 and VcH2 Supply Voltage ................................ PGOOD.................................................................... Storage Temperature Range ...................................... Junction Temperature Range ..................................... ESD Classification ................................................... -0.5V To 16V -0.5V To 25V -0.5V To 16V -55°C To 150°C -40°C To 150°C JEDEC, JESD22-A114 Caution: Stresses above those listed in “Absolute Maximum Rating” may cause permanent damage to the device. These are stress ratings only and function of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to “Absolute Maximum Rating” conditions for extended periods may affect device reliability RECOMMENDED OPERATING CONDITIONS Parameter Vcc VcH1,2 Fs Tj Definition Supply Voltage Supply Voltage Operating Frequency Junction Temperature Min 5.5 10 200 -40 Max 14.5 20 500 125 Units V V kHz °C PACKAGE INFORMATION IR3621F 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 IR3621M & IR3621MPbF 32-Lead MLPQ 5mmx5mm (M) PG ood Gn d VR UT 3 NC Vc c EF 32 Rt VSEN2 Fb2 1 2 31 30 29 28 27 VP2 26 VO 25 24 Hiccup 23 Sync 22 VSEN1 3 4 Comp2 SS2/SD2 5 NC 21 Fb1 20 Comp1 19 SS1/SD1 18 OCSet1 17 VcH1 16 Pad OCSet2 6 VCH2 HDrv2 7 8 9 10 11 12 13 14 15 NC PG nd2 LD rv2 LD rv1 PG nd1 NC θJA = 75.5 °C/W θJC =13.3 °C/W θJA = 36.0 °C/W θJC = 1.0 °C/W Exposed pad on underside is connected to a copper pad through vias for 4-layer PCB board design. 2 www.irf.com HD rv1 VC L IR3621 & (PbF) ELECTRICAL SPECIFICATIONS Unless otherwise specified, these specifications apply over Vcc=12V, VcH1=VcH2=VCL=12V and 0°C