Data Sheet No.PD60231 revB IR3621 & (PbF) 2-PHASE / DUAL SYNCHRONOUS PWM CONTROLLER WITH OSCILLATOR SYNCHRONIZATION AND PRE-BIAS STARTUP FEATURES DESCRIPTION Dual Synchronous Controller with 180 The IR3621 IC combines a dual synchronous buck control- Out of Phase Operation ler and drivers, providing a cost-effective, high performance Configurable to 2-Independent Outputs or and flexible solution. The IR3621 operates in 2-Phase mode Current Share Single Output to produce either 2-independent output voltages or current Voltage Mode Control share single output for high current application. The 180 Current Sharing Using Inductor s DCR out-of-phase operation allows the reduction of input and Selectable Hiccup or Latched Current output capacitance. Limit using MOSFET s R sensing DS(on) Other key features include two independently programmable Latched Over-Voltage Protection soft-start functions to allow system level sequencing of out- Pre-Bias Start Up put voltages in various configurations. The pre-bias protec- Programmable Switching Frequency up to 500KHz tion feature prevents the discharge of the output voltage and Two Independent Soft-Starts/Shutdowns possible damage to the load during start-up when a pre- Precision Reference Voltage 0.8V existing voltage is present at the output. Programmable Power Good Output switching frequency up to 500KHz per phase allows flexibil- External Frequency Synchronization ity to tune the operation of the IC to meet system level re- Thermal Protection quirements, and synchronization allows the simplification of system level filter design. Protection features such as APPLICATIONS selectable hiccup or latched current limit, and under voltage Embedded Networking & Telecom Systems lock-out are provided to give required system level security Distributed Point-of-Load Power Architectures in the event of a fault condition. 2-Phase Power Supply Graphics Card DDR Memory Applications Vin Vin HDrv1 Rt HDrv1 Rt OCSet1 OCSet1 Vout1 Comp1 Comp1 LDrv1 LDrv1 PGnd1 PGnd1 Vin Vout Vin IR3621 IR3621 Comp2 Comp2 SS1 / SD SS1 / SD HDrv2 HDrv2 SS2 / SD OCSet2 OCSet2 Vout2 SS2 / SD Gnd LDrv2 LDrv2 PGnd2 PGnd2 Gnd 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 T & R PART LEADFREE PIN PARTS PARTS DESIG NUMBER PART NUMBER COUNT PER TUBE PER REEL Orientation M IR3621M IR3621MPbF 32 73 ------ M IR3621MTR IR3621MTRPbF 32 ------ 6000 Fig A F IR3621F IR3621FPbF 28 50 ------ F IR3621FTR IR3621FTRPbF 28 ------ 2500 www.irf.com 1IR3621 & (PbF) 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 ...................................... -55C To 150C Junction Temperature Range ..................................... -40C To 150C ESD Classification ................................................... 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 specifica- tions is not implied. Exposure to Absolute Maximum Rating conditions for extended periods may affect device reliability RECOMMENDED OPERATING CONDITIONS Parameter Definition Min Max Units Vcc Supply Voltage 5.5 14.5 V VcH1,2 Supply Voltage 10 20 V Fs Operating Frequency 200 500 kHz Tj Junction Temperature -40 125 C PACKAGE INFORMATION IR3621F IR3621M & IR3621MPbF 28-PIN TSSOP (F) 32-Lead MLPQ 5mmx5mm (M) PGood 1 28 Gnd 2 27 VCC VREF 28 32 31 30 29 27 26 25 3 26 VP2 VOUT3 24 Hiccup Rt 1 4 25 Rt Hiccup 23 Sync VSEN2 2 5 24 Sync VSEN2 VSEN1 Fb2 6 23 VSEN1 22 Fb2 3 Comp2 7 22 Fb1 4 21 Fb1 Comp2 Pad SS2 / SD 8 21 Comp1 SS2/SD2 5 20 Comp1 9 20 SS1 / SD OCSet2 OCSet2 6 19 SS1/SD1 VcH2 10 19 OCSet1 HDrv2 11 18 VcH1 VCH2 7 18 OCSet1 PGnd2 12 17 HDrv1 17 HDrv2 VcH1 8 13 LDrv2 16 PGnd1 15 9 11 13 14 16 10 12 VCL 14 15 LDrv1 JA = 75.5 C/W JC =13.3 C/W JA = 36.0 C/W JC = 1.0 C/W Exposed pad on underside is connected to a copper pad through vias for 4-layer PCB board design. www.irf.com 2 NC VOUT3 Vcc PGood Gnd VREF NC VP2 PGnd2 NC LDrv2 VCL LDrv1 PGnd1 NC HDrv1