DATASHEET ISL85415 FN8373 Rev 4.00 Wide V 500mA Synchronous Buck Regulator IN October 30, 2014 The ISL85415 is a 500mA Synchronous buck regulator with an Features input range of 3V to 36V. It provides an easy to use, high Wide input voltage range 3V to 36V efficiency low BOM count solution for a variety of applications. Synchronous Operation for high efficiency The ISL85415 integrates both high-side and low-side NMOS FET s and features a PFM mode for improved efficiency at light No compensation required loads. This feature can be disabled if forced PWM mode is Integrated High-side and Low-side NMOS devices desired. The part switches at a default frequency of 500kHz Selectable PFM or forced PWM mode at light loads but may also be programmed using an external resistor from 300kHz to 2MHz. The ISL85415 has the ability to utilize Internal fixed (500kHz) or adjustable Switching frequency internal or external compensation. By integrating both NMOS 300kHz to 2MHz devices and providing internal configuration options, minimal Continuous output current up to 500mA external components are required, reducing BOM count and Internal or external soft-start complexity of design. Minimal external components required With the wide V range and reduced BOM the part provides an IN easy to implement design solution for a variety of applications Power-good and enable functions available. while giving superior performance. It will provide a very robust design for high voltage Industrial applications as well as an Applications efficient solution for battery powered applications. Industrial control The part is available in a small Pb free 4mmx3mm DFN plastic Medical devices package with an operation temperature range of -40C to Portable instrumentation +125C Distributed Power supplies Related Literature Cloud Infrastructure AN1859, ISL85415EVAL1Z Wide V 500mA Synchronous IN Buck Regulator AN1860 ISL85415DEMO1Z Wide V 500mA Synchronous IN Buck Regulator 100 V = 12V V = 5V V = 15V IN IN IN 95 90 1 12 SS FS 85 2 11 80 COMP SYNC R 2 CFB 10 75 3 BOOT FB CBOOT GND 100nF 9 4 R3 70 V = 33V VIN IN C VCC VIN V = 24V IN CVCC 10F 1F 5 65 V OUT PHASE PG COUT L1 60 6 10F 22H PGND EN 55 50 INTERNAL DEFAULT PARAMETER SELECTION 0 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 0.50 OUTPUT LOAD (A) FIGURE 1. TYPICAL APPLICATION FIGURE 2. EFFICIENCY vs LOAD, PFM, V = 3.3V OUT FN8373 Rev 4.00 Page 1 of 24 October 30, 2014 EFFICIENCY (%)ISL85415 Table of Contents Typical Application Schematics 4 Functional Block Diagram 5 Ordering Information 5 Absolute Maximum Ratings . 6 Thermal Information . 6 Recommended Operating Conditions 6 Electrical Specifications . 6 Efficiency Curves 8 Efficiency Curves . 10 Typical Performance Curves . 12 Detailed Description 17 Power-On Reset . 17 Soft Start . 17 Power-Good 17 PWM Control Scheme 17 Light Load Operation . 17 Output Voltage Selection . 18 Protection Features . 18 Overcurrent Protection . 18 Negative Current Limit . 18 Over-Temperature Protection 19 Boot Undervoltage Protection . 19 Application Guidelines 19 Simplifying the Design . 19 Operating Frequency . 19 Synchronization Control 19 Output Inductor Selection . 19 Buck Regulator Output Capacitor Selection 19 Loop Compensation Design . 20 Layout Considerations 22 Revision History 23 About Intersil 23 Package Outline Drawing 24 FN8373 Rev 4.00 Page 2 of 24 October 30, 2014