17mm DATASHEET ISL8240M FN8450 Rev 2.00 Dual 20A/Single 40A Step-Down Power Module January 7, 2015 The ISL8240M is a fully-encapsulated step-down switching Features power supply that can deliver up to 100W output power from a small 17mmx17mm PCB footprint. The two 20A outputs may Fully-encapsulated dual step-down switching power supply be used independently or combined to deliver a single output Up to 100W output from a 17mmx17mm PCB footprint of 40A. Designing a high-performance board-mounted power supply has never been simpler -- only a few external Dual 20A or single 40A output components are needed to create a very dense and reliable Up to 94% conversion efficiency power solution. 4.5V to 20V input voltage range 1.5% output voltage accuracy, differential remote voltage 0.6V to 2.5V output voltage range sensing and fast transient response create a very high-performance power system. Built-in output overvoltage, 1.5% output voltage accuracy with differential remote overcurrent and over-temperature protection enhance system sensing reliability. Output overvoltage, overcurrent and over-temperature The ISL8240M is available in a thermally-enhanced QFN protection package. Excellent efficiency and low thermal resistance QFN package with exposed leads permits easy probing and permit full power operation without heat sinks or fans. In visual solder inspection addition, the QFN package with external leads permits easy probing and visual solder inspection. Applications Related Literature Computing, networking and telecom infrastructure AN1922, ISL8240MEVAL4Z Dual 20A/Optional 40A equipment Cascadable Evaluation Board Setup Procedure Industrial and medical equipment AN1923, ISL8240MEVAL3Z 40A, Single Output Evaluation General purpose point-of-load (POL) power Board Setup Procedure 4.5V TO 20V 1.0VAT 40A V VIN1 VOUT1 V IN OUT 5x22F VIVIN2N2 VOUT2 1k 7.5mm VSEN1+ R SET EN/FF1 9x100F OFF ON 1.5k EN/FF2 VSEN1- ISL8240M VSEN2- VMON1 VCC VMON2 SYNC COMP1 4.7F R SYNC COMP2 237k 470pF NOTE: All pins not shown are floating FIGURE 1. COMPLETE 40A STEP-DOWN POWER SUPPLY FIGURE 2. SMALL FOOTPRINT WITH HIGH POWER DENSITY FN8450 Rev 2.00 Page 1 of 31 January 7, 2015 17mm MODE SGND PGNDISL8240M Table of Contents Pinout Internal Circuit 3 Ordering Information 4 Pin Configuration 5 Pin Descriptions . 6 Absolute Maximum Ratings . 7 Thermal Information . 7 Recommended Operating Conditions 7 Electrical Specifications . 7 Typical Performance Characteristics 10 Efficiency Performance . 10 Transient Response Performance 11 Start-up and Short Circuit Performance . 13 Typical Application Circuits 14 Application Information . 21 Programming the Output Voltage 21 Selection of Input Capacitor . 21 Selection of Output Capacitors 21 EN/FF Turn ON/OFF 21 Thermal Considerations 22 Functional Description 22 Initialization 22 Enable and Voltage Feed-forward 22 Soft-Start . 23 Power-Good 23 Current Share . 23 Overvoltage Protection (OVP) 24 Over-Temperature Protection (OTP) 24 Overcurrent Protection (OCP) 24 Frequency Synchronization and Phase Lock Loop 24 Tracking Function . 25 Mode Programming 25 Layout Guide . 25 Current Derating 26 Package Description 26 PCB Layout Pattern Design . 26 Thermal Vias 26 Stencil Pattern Design . 26 Power Loss Curves 27 Derating Curves 27 Reflow Parameters 28 Revision History 29 About Intersil 29 Package Outline Drawing 30 FN8450 Rev 2.00 Page 2 of 31 January 7, 2015