IR IR3895 16A SupIRBuck 同步降压稳压器解决方案

发布时间：2012-7-3 12:14 发布者：1770309616

IR公司的IR3895是SupIRBuck容易使用的全集成和高效率的同步降压DC/DC稳压器,包括了PWM控制器和MOSFET,输入电压5-12V,输出电压0.5V到0.86xVin,输出电流高达16A,可编开关频率高达1.5MHz,内部数字软起动/软停止.主要用在网络设备,嵌入通信系统,服务器,存储设备和分布式POL电源架构.本文介绍了IR3895主要特性, 方框图, POL转换器应用电路图和推荐的材料清单,以及IR3895评估板主要特性,电路图,材料清单和PCB元件布局图.

The IR3895 SupIRBuckTM is an easy‐to‐use, fully integrated and highly efficient DC/DC regulator. The onboard PWM controller and MOSFETs make IR3895 a space‐efficient solution, providing accurate power delivery for low output voltage applications.

IR3895 is a versatile regulator which offers programmability of switching frequency and internal current limit while operates in wide input and output voltage range.

The switching frequency is programmable from 300kHz to 1.5MHz for an optimum solution.

It also features important protection functions, such as Pre‐Bias startup, thermally compensated current limit, over voltage protection and thermal shutdown to give required system level security in the event of fault conditions.

IR3895主要特性:

 Single 5V to 21V application

 Wide Input Voltage Range from 1.0V to 21V with external Vcc

 Output Voltage Range: 0.5V to 0.86* Vin

 Enhanced Line/Load Regulation with Feed‐Forward

 Programmable Switching Frequency up to 1.5MHz

 Internal Digital Soft‐Start/Soft‐Stop

 Enable input with Voltage Monitoring Capability

 Thermally Compensated Current Limit with robust hiccup mode over current protection

 Smart internal LDO to improve light load and full load efficiency

 External Synchronization with Smooth Clocking

 Enhanced Pre‐Bias Start‐Up

 Precision Reference Voltage (0.5V+/‐0.5%) with margining capability

 Vp for Tracking Applications (source/sink capability ±16A)

 Integrated MOSFET drivers and Bootstrap Diode

 Thermal Shut Down

 Programmable Power Good Output with tracking capability

 Monotonic Start‐Up

 Operating temp: ‐40oC < Tj < 125oC

 Small Size: 5mm x 6mm PQFN

 Lead‐free, Halogen‐free and RoHS Compliant

IR3895主要应用:

 Netcom Applications

 Embedded Telecom Systems

 Server Applications

 Storage Applications

 Distributed Point of Load Power Architectures

图1.IR3895方框图

图2.IR3895 POL转换器应用电路图:12V输入,1.2V/16A输出
图2 POL转换器应用电路推荐材料清单:

IR3895评估板
This user guide contains the schematic and bill of materials for the IR3895 evaluation board.

The guide describes operation and use of the evaluation board itself. Detailed application
information for IR3895 is available in the IR3895 data sheet.

IR3895评估板主要特性:

• Vin = +12V (+ 13.2V Max)

•Vout = +1.2V @ 0- 16A

• Fs=600kHz

• L= 0.4uH

• Cin= 5x10uF (ceramic 1206) + 1X330uF (electrolytic)

• Cout=6x47uF (ceramic 0805)