IR3812MPBF

PD-60335 IR3812MPbF SupIRBuck Features • • • • • • • • • • • • • • TM HIGHLY INTEGRATED 4A Description The IR3812 SupIRBuckTM is an easy-to-use, fully integrated and highly efficient DC/DC regulator. The onboard switching controller and MOSFETs make the IR3812 a space-efficient solution, providing accurate power delivery for low output voltage applications. The IR3812 operates from a single 4.5V to 14V input supply and generates an output voltage adjustable from 0.6V to 0.80*Vin at loads up to 4A. IR3812 can be configured for tracking applications to generate termination voltage (VTT) for memory applications. A versatile regulator offering programmability of start up time and current limit, the IR3812’s fixed 600kHz switching frequency allows the use of small external components. IR3812 also features important protection functions, such as Pre-Bias startup, hiccup current limit and thermal shutdown to provide the required system level security in the event of fault conditions. WIDE-INPUT VOLTAGE, SYNCHRONOUS BUCK REGULATOR Wide Input Voltage Range 2.5V to 21V Wide Output Voltage Range 0.6V to 12V Continuous 4A Load Capability 600kHz High Frequency Operation Programmable Over-Current-Protection Hiccup Current Limit Tracking capability for Memory Application Precision Reference Voltage (0.6V) Programmable Soft-Start Pre-Bias Start-up Thermal Protection Thermally Enhanced Package Small Size 5mmx6mm QFN Pb-Free (RoHS Compliant) Applications • • • • • • • • Distributed Point-of-Loads Server and Workstations Embedded Systems Storage Systems DDR Applications Graphics Cards Game Consoles Computing Peripheral Voltage Regulators Fig. 1. Typical application diagram 01/08/08 1 PD-60335 IR3812MPbF ABSOLUTE MAXIMUM RATINGS (Voltages referenced to GND) • • • • • • • • • • • • VIN Supply Voltage Vcc Supply Voltage Vc Supply Voltage SW PGood Fb,COMP,SS,Vsns OCSet AGnd to PGnd Storage Temperature Range Operating Junction Temperature Range ESD Classification Moisture Sensitivity Level -0.3V to 24V -0.3V to 16V -0.3V to 30V -0.3V to 30V -0.3V to 16V -0.3V to 3.5V 10mA -0.3V to +0.3V -65°C To 150°C -40°C To 150°C JEDEC, JESD22-A114 JEDEC Level 3 @ 260oC Caution: Stresses beyond those listed under “Absolute Maximum Rating” may cause permanent damage to the device. These are stress ratings only and functional operation 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. PACKAGE INFORMATION 5mm x 6mm POWER QFN 12 VIN 11 SW 10 PGnd θJA = 35 o C / W θJ -PCB = 2 o C / W HG Vc 13 14 1 Vp 15 AGnd 9 8 Vref VCC 2 3 4 5 6 7 FB COMP AGnd AGnd SS OCSet Fig. 2: Package outline (Top view) ORDERING INFORMATION PKG DESIG M PACKAGE DESCRIPTION IR3812MTRPbF PIN COUNT 15 PARTS PER TUBE --------------PARTS PER REEL 4000 01/08/08 2 PD-60335 IR3812MPbF Block Diagram Fig. 3. Simplified block diagram of the IR3812. 01/08/08 3 PD-60335 IR3812MPbF Pin Description Pin 1 2 Name Vp Fb Description Non-inverting input of error amplifier. This pin can be used for tracking application. Inverting input to the error amplifier. This pin is connected directly to the output of the regulator via resistor divider to set the output voltage and provide feedback to the error amplifier. Output of error amplifier. An external resistor and capacitor network is typically connected from this pin to ground to provide loop compensation. Signal ground for internal reference and control circuitry. Signal ground for internal reference and control circuitry. Soft start / shutdown. This pin provides user programmable soft-start function. Connect an external capacitor from this pin to ground to set the start up time of the output voltage. The converter can be shutdown by pulling this pin below 0.3V. Current limit set point. A resistor from this pin to SW pin will set the current limit threshold. This pin powers the internal IC as well as low side driver. A minimum of 0.1uF high frequency capacitor must be connected from this pin to the power ground. External reference voltage. Drive capability for this pin is 2μA. Power Ground. This pin serves as a separated ground for the MOSFET drivers and should be connected to the system’s power ground plane. Switch node. This pin is connected to the output inductor Input voltage connection pin This pin is connected to the high side gate driver. Connect a small capacitor from this pin to switch node (SW). This pin powers the high side driver and must be connected to a voltage higher than input voltage. A minimum of 0.1uF high frequency capacitor must be connected from this pin to the power ground for the charge-pump high side drive scheme. Signal ground for internal reference and control circuitry. 3 4 5 6 Comp AGnd AGnd SS/SD 7 8 9 10 11 12 13 14 OCSet VCC Vref PGnd SW VIN HG VC AGnd 15 Pins 4, 5 and 15 need to be connected together on system board. 01/08/08 4 PD-60335 IR3812MPbF Recommended Operating Conditions Symbol Vin Vcc Vc Vo Io Note1 Tj Definition Input Voltage Supply Voltage Supply Voltage Output Voltage Output Current Junction Temperature Min 2.5 4.5 Vin + 5V 0.6 0 -40 Max 21 14 28 12 4 125 Units V A C o Electrical Specifications Unless otherwise specified, these specification apply over Vin=Vcc=Vc=12V, 0oC