IR3856MTRPBF

PD-97528 IR3856MPbF SupIRBuck HIGHLY EFFICIENT TM INTEGRATED 6A, SYNCHRONOUS BUCK REGULATOR Features • • • • • • • • • • • • • • • • • • • • • • Applications • • • Description Greater than 95% Maximum Efficiency Wide Input Voltage Range 1.5V to 21V Wide Output Voltage Range 0.7V to 0.9*Vin Continuous 6A Load Capability Integrated Bootstrap-diode High Bandwidth E/A for excellent transient performance Programmable Switching Frequency up to 1.5MHz Programmable Over Current Protection Over Voltage Protection Dedicated input for output voltage monitoring Programmable PGood output Hiccup Current Limit Precision Reference Voltage (0.7V, +/-1%) Programmable Soft-Start Enable Input with Voltage Monitoring Capability Enhanced Pre-Bias Start-up Seq input for Tracking applications External Synchronization -40oC to 125oC operating junction temperature Thermal Protection 4mm x 5mm Power QFN Package Halogen Free, Lead Free and RoHS compliant Server Applications Storage Applications Embedded Telecom Systems The IR3856 SupIRBuckTM is an easy-to-use, fully integrated and highly efficient DC/DC synchronous Buck regulator. The MOSFETs copackaged with the on-chip PWM controller make IR3856 a space-efficient solution, providing accurate power delivery for low output voltage applications. IR3856 is a versatile regulator which offers programmability of start up time, switching frequency and current limit while operating in wide input and output voltage range. The switching frequency is programmable from 250kHz to 1.5MHz for an optimum solution. It also features important protection functions, such as Pre-Bias startup, hiccup current limit and thermal shutdown to give required system level security in the event of fault conditions. • • • • Distributed Point of Load Power Architectures Netcom Applications Computing Peripheral Voltage Regulators General DC-DC Converters Fig. 1. Typical application diagram Rev 4.0 1 PD-97528 IR3856MPbF ABSOLUTE MAXIMUM RATINGS (Voltages referenced to GND unless otherwise specified) • Vin ……………………………………………………. -0.3V to 25V • Vcc ……………….….…………….……..……….…… -0.3V to 8V (Note2) • Boot ……………………………………..……….…. -0.3V to 33V • SW …………………………………………..……… -0.3V to 25V(DC), -4V to 25V(AC, 100ns) • Boot to SW • OCSet • Input / output Pins • PGND to GND ……………...………………………….. -0.3V to +0.3V • Storage Temperature Range ................................... -55°C To 150°C • Junction Temperature Range ................................... -40°C To 150°C (Note2) • ESD Classification …………………………… ……… JEDEC Class 1C • Moisture sensitivity level………………...………………JEDEC Level 3@260 °C (Note5) ……..…………………………….…..….. -0.3V to Vcc+0.3V (Note1) ………………………………………….……. -0.3V to 30V (Max 30mA) ……………………………….. ... -0.3V to Vcc+0.3V (Note1) Note1: Must not exceed 8V Note2: Vcc must not exceed 7.5V for Junction Temperature between -10oC and -40oC Stresses beyond those listed under “Absolute Maximum Ratings” 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 are not implied. PACKAGE INFORMATION 4mm x 5mm POWER QFN θ JA( Sync _ FET ) = 45 o C / W * 13 12 VIN SW 11 θ JA( Ctrl _ FET ) = 45 o C / W * PGnd θ J -PCB = 2 o C / W Exposed pads on underside are connected to copper pads of a 4-layer (2 oz.) PCB * Boot 14 Enable 15 Seq 16 1 ORDERING INFORMATION Rev 4.0 10 17 Gnd 2 3 4 5 Fb Vsns COMP Gnd Rt 6 Vcc 9 Sync 8 PGood 7 SS OCSet PACKAGE DESIGNATOR PACKAGE DESCRIPTION PIN COUNT PARTS PER REEL M IR3856MTRPbF 17 4000 M IR3856MTR1PbF 17 750 2 PD-97528 IR3856MPbF Block Diagram Fig. 2. Simplified block diagram of the IR3856 Rev 4.0 3 PD-97528 IR3856MPbF Pin Description Pin Name Description 1 Fb 2 Vsns 3 Comp 4;17 Gnd 5 Rt 6 SS/SD 7 OCSet 8 PGood Power Good status pin. Output is open drain. Connect a pull up resistor from this pin to Vcc. 9 Sync Sync pin, connect external system clock to synchronize multiple POLs with the same frequency 10 V CC 11 PGnd This pin powers the internal IC and the drivers. A minimum of 1uF high frequency capacitor must be connected from this pin to the power ground (PGnd). Power Ground. This pin serves as a separated ground for the MOSFET drivers and should be connected to the system’s power ground plane. 12 SW Switch node. This pin is connected to the output inductor. 13 VIN Input voltage connection pin. 14 Boot 15 Enable 16 Seq Rev 4.0 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. Sense pin for PGood Output of error amplifier. An external resistor and capacitor network is typically connected from this pin to Fb pin to provide loop compensation. Signal ground for internal reference and control circuitry. Set the switching frequency. Connect an external resistor from this pin to Gnd to set the switching frequency. See Table 1 for Fs vs. Rt. Soft start / shutdown. This pin provides user programmable soft-start function. Connect an external capacitor from this pin to Gnd 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. Supply voltage for high side driver. A 0.1uF capacitor must be connected from this pin to SW. Enable pin to turn on and off the device. Use two external resistors to set the turn on threshold (see Enable section). Connect this pin to Vcc if it is not used. Sequence pin. Use two external resistors to set Simultaneous Power up sequencing. If this pin is not used connect to Vcc. 4 PD-97528 IR3856MPbF Recommended Operating Conditions Symbol Vin Vcc Boot to SW Vo Io Fs Tj Definition Input Voltage Supply Voltage Supply Voltage Output Voltage Output Current Switching Frequency Junction Temperature Min Max 1.5 4.5 4.5 0.7 0 225 -40 21* 5.5 5.5 0.9*Vin 6 1650 125 Units V A kHz o C * Note: SW node should not exceed 25V Electrical Specifications Unless otherwise specified, these specification apply over 4.5V< Vcc