DATASHEET ISL85418 FN8369 Rev.6.00 Wide V 800mA Synchronous Buck Regulator IN Mar 15, 2019 The ISL85418 is a 800mA synchronous buck regulator with an Features input range of 3V to 40V. It provides an easy-to-use, high Wide input voltage range: 3V to 40V efficiency low BOM count solution for a variety of applications. Synchronous operation for high efficiency The ISL85418 integrates both high-side and low-side NMOS FETs 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 needed. The ISL85418 switches at a default frequency of Selectable PFM or forced PWM mode at light loads 500kHz however, it can also be programmed using an external resistor from 300kHz to 2MHz. The ISL85418 has the Internal fixed frequency (500kHz) or adjustable switching ability to use internal or external compensation. By integrating frequency (300kHz to 2MHz) both NMOS devices and providing internal configuration Continuous output current up to 800mA options, minimal external components are required, which Internal or external soft-start reduces the BOM count and design complexity. Minimal external components required With a wide V range and reduced BOM, the ISL85418 IN provides an easy to implement design solution for a variety of Power-good and enable functions available applications while giving superior performance. The ISL85418 provides a very robust design for high-voltage industrial Applications applications and an efficient solution for battery powered Industrial control applications. Medical devices The ISL85418 is available in a small Pb-free 4mmx3mm DFN Portable instrumentation plastic package with an operation temperature range of -40C Distributed power supplies to +125C. Cloud infrastructure Related Literature For a full list of related documents, visit our website: ISL85418 device page 100 V = 12V IN V = 5V 95 IN 90 1 12 SS FS 85 11 2 80 COMP SYNC R2 C FB 10 3 75 V = 33V BOOT FB IN C V = 15V BOOT IN GND 100nF 9 4 R3 70 VIN C VCC VIN C VCC 10F 1F 65 VOUT 5 PHASE PG C OUT L1 60 V = 24V 6 IN 10F 22H PGND EN 55 50 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 INTERNAL DEFAULT PARAMETER SELECTION OUTPUT LOAD (A) FIGURE 1. TYPICAL APPLICATION FIGURE 2. EFFICIENCY vs LOAD, PFM, V = 3.3V OUT FN8369 Rev.6.00 Page 1 of 22 Mar 15, 2019 EFFICIENCY (%)ISL85418 Table of Contents Pin Configuration 3 Pin Descriptions . 3 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 Measurements . 10 Detailed Description 14 Power-On Reset . 14 Soft-Start . 14 Power-Good 14 PWM Control Scheme 14 Light Load Operation . 15 Output Voltage Selection . 15 Protection Features . 15 Overcurrent Protection . 15 Negative Current Limit . 16 Over-Temperature Protection 16 Boot Undervoltage Protection . 16 Application Guidelines 16 Simplifying the Design . 16 Operating Frequency . 16 Minimum On/Off-Time Limitation 16 Synchronization Control 17 Output Inductor Selection . 17 Buck Regulator Output Capacitor Selection 17 Loop Compensation Design . 17 Layout Considerations 19 Revision History 20 Package Outline Drawing 21 FN8369 Rev.6.00 Page 2 of 22 Mar 15, 2019