Intersil公司的ISL85415A是一款输入范围为3V到36V的500mA同步降压稳压调节器，为各种各样应用提供易用、高效及少量外围器件的电源解决方案。该芯片同时集成高边及低边NMOS FET场效应管。在轻载情况下，工作在PFM工作模式以最大限度提高效率，如采用PWM工作模式下PFM提高效率工作模式失效。开关频率默认为500kHz，可通过外部电阻设置开关频率为300kHz到2MHz。本文首先介绍芯片的简介、特性、内部框图及应用领域，并给出相应设计方案的设计原理图、元器件列表及PCB元件布局图。

The ISL85415A is a 500mA Synchronous buck regulator with an input range of 3V to 36V. It provides an easy to use, high efficiency low BOM count solution for a variety of applications.

The ISL85415A integrates both high-side and low-side NMOS FET’s and features a PFM mode for improved efficiency at light loads. This feature can be disabled if forced PWM mode is desired. The part switches at a default frequency of 500kHz but may also be programmed using an external resistor from 300kHz to 2MHz. The ISL85415A has the ability to utilize internal or external compensation. By integrating both NMOS devices and providing internal configuration options, minimal external components are required, reducing BOM count and complexity of design.

With the wide VIN range and reduced BOM the part provides an easy to implement design solution for a variety of applications while giving superior performance. It will provide a very robust design for high voltage Industrial applications as well as an efficient solution for battery powered applications.

The part is available in a small Pb free 4mmx3mm DFN plastic package with an operation temperature range of -40°C to +85°C

ISL85415A主要特性：

• Wide input voltage range 3V to 36V
• Synchronous operation for high efficiency
• No compensation required
• Integrated High-side and Low-side NMOS devices
• Selectable PFM or forced PWM mode at light loads
• Internal fixed (500kHz) or adjustable switching frequency 300kHz to 2MHz
• Continuous output current up to 500mA
• Internal or external soft-start
• Minimal external components required
• Power-good and enable functions available.

ISL85415A应用：

• Industrial control
• Medical devices
• Portable instrumentation
• Distributed power supplies
• Cloud Infrastructure

 
图1. ISL85415A内部方框图

ISL85415A方案介绍：

The ISL85415EVAL1Z, ISL85415AEVAL1Z kit is intended for use for Point-of-Load applications sourcing from 3V to 36V.The kit is used to demonstrate the performance of the ISL85415, ISL85415A Wide VIN Low Quiescent Current High Efficiency Sync Buck Regulator with 500mA output current. The ISL85415, ISL85415A are offered in a 4mmx3mm 12 Ld DFN package with 1mm maximum height. The converter occupies 1.516 cm2 area.

ISL85415A方案原理图：

图2. ISL85415A方案原理图

ISL85415A方案材料清单：





PCB元件布局图：