Dual output, 4A/Phase, Highly Integrated SupIRBuck IR3891 Single-Input Voltage, Synchronous Buck Regulator FEATURES DESCRIPTION Single 5V to 21V application The IR3891 SupIRBuck is an easy-to-use, fully integrated and highly efficient DC/DC regulator. The Wide Input Voltage Range from 1V to 21V with external Vcc onboard PWM controller and MOSFETs make IR3891 a space-efficient solution, providing accurate power Output Voltage Range: 0.5V to 0.86*PVin delivery for low output voltage. Dual output, 4A/Phase Enhanced Line/Load Regulation with Feed- IR3891 is a versatile regulator which offers Forward programmability of switching frequency and a fixed current limit while operating in wide input and output Programmable Switching Frequency up to 1.5MHz voltage range. Internal Digital Soft-Start Enable input with Voltage Monitoring Capability The switching frequency is programmable from 300kHz to 1.5MHz for an optimum solution. Thermally compensated current limit and Hiccup Mode Over Current Protection It also features important protection functions, such as External synchronization with Smooth Clocking Over Voltage Protection (OVP), Pre-Bias startup, Precision Reference Voltage (0.5V +/-1%) hiccup current limit and thermal shutdown to give Seq pin for Sequencing Applications required system level security in the event of fault conditions. Integrated MOSFETs, drivers and Bootstrap diode Thermal Shut Down APPLICATIONS Open Feedback Line Protection Sever Applications Over Voltage Protection Netcom Applications Interleaved Phases to reduce Input Capacitors Set Top Box Applications Monotonic Start-Up o o Operating Junction Temp: -40 C<Tj<125 C Storage Applications Small Size 5mm x 6mm PQFN Embedded telecom Systems Lead-free, Halogen-free, and RoHS Compliant Distributed Point of Load Power Architectures Computing Peripheral Voltage regulators General DC-DC Converters ORDERING INFORMATION Base Part Standard Pack Orderable Part Package Type Form Quantity Number Number IR3891 PQFN 5mm x 6mm Tape and Reel 4000 IR3891MTRPBF IR3891 PBF Lead Free TR Tape and Reel Package Type M 1 www.irf.com 2014 International Rectifier Submit Datasheet Feedback May 29, 2014 EN1 EN2 IR3891 BASIC APPLICATION 5V < Vin < 21V 93 91 89 Seq Vcc PG2 PG1 Vin 87 PVin1/2 Boot2 85 Boot1 Vo2 Vo1 83 SW2 SW1 81 Vsns2 Vsns1 79 77 Fb2 Fb1 75 Comp1 Comp2 Rt/ Sync Gnd PGnd1/2 73 0.5 1 1.5 2 2.5 3 3.5 4 Load Current A 1.2V 1.8V Figure 2: Efficiency Vin=12V, Fsw=600kHz Figure 1: IR3891 Basic Application Circuit PIN DIAGRAM 5mm X 6mm POWER QFN Top View 22 21 20 19 PGnd1 23 18 PGnd2 PGnd1 24 17 PGnd2 SW1 SW2 16 PGnd2 PGnd1 25 15 PVin2 PVin1 26 PVin1 27 14 PVin2 Boot1 28 13 Boot2 PGood1 29 12 PGood2 Comp1 30 11 Comp2 FB1 31 10 FB2 1 2 3 4 5 6 7 8 9 2 www.irf.com 2014 International Rectifier Submit Datasheet Feedback May 29, 2014 Vsns1 EN1 Vin VCC/LDO out GND Seq Efficiency % RT/Sync EN2 Vsns2