参数资料
型号: PTH08T240WAZ
厂商: TEXAS INSTRUMENTS INC
元件分类: 电源模块
英文描述: 1-OUTPUT DC-DC REG PWR SUPPLY MODULE
封装: ROHS COMPLIANT PACKAGE-11
文件页数: 5/39页
文件大小: 1366K
代理商: PTH08T240WAZ
CAPACITOR RECOMMENDATIONS FOR THE PTH08T240/241W POWER MODULE
Capacitor Technologies
Input Capacitor (Required)
Input Capacitor Information
www.ti.com ................................................................................................................................................... SLTS264J – NOVEMBER 2005 – REVISED JUNE 2009
Electrolytic Capacitors
When using electrolytic capacitors, high quality, computer-grade electrolytic capacitors are recommended.
Aluminum electrolytic capacitors provide adequate decoupling over the frequency range, 2 kHz to 150 kHz,
and are suitable when ambient temperatures are above -20°C. For operation below -20°C, tantalum,
ceramic, or OS-CON type capacitors are required.
Ceramic Capacitors
Above 150 kHz the performance of aluminum electrolytic capacitors is less effective. Multilayer ceramic
capacitors have very low ESR and a resonant frequency higher than the bandwidth of the regulator. They
can be used to reduce the reflected ripple current at the input as well as improve the transient response of
the output.
Tantalum, Polymer-Tantalum Capacitors
Tantalum type capacitors may only used on the output bus, and are recommended for applications where the
ambient operating temperature is less than 0°C. The AVX TPS series and Kemet capacitor series are
suggested over many other tantalum types due to their lower ESR, higher rated surge, power dissipation,
and ripple current capability. Tantalum capacitors that have no stated ESR or surge current rating are not
recommended for power applications.
The PTH08T241W requires a minimum input capacitance of 200
F of ceramic type.
The PTH08T240W requires a minimum input capacitance of 220
F electrolytic type. The ripple current rating of
the electrolytic capacitor must be at least 700mArms when VO≥3V. The ripple current rating must be at least
450mArms when VO<3 V. An optional 22F X5R/X7R ceramic is recommended to reduce the RMS ripple
current.
The size and value of the input capacitor is determined by the converter’s transient performance capability. This
minimum value assumes that the converter is supplied with a responsive, low inductance input source. This
source should have ample capacitive decoupling, and be distributed to the converter via PCB power and ground
planes.
Ceramic capacitors should be located as close as possible to the module's input pins, within 0.5 inch (1,3 cm).
Adding ceramic capacitance is necessary to reduce the high-frequency ripple voltage at the module's input. This
will reduce the magnitude of the ripple current through the electroytic capacitor, as well as the amount of ripple
current reflected back to the input source. Additional ceramic capacitors can be added to further reduce the RMS
ripple current requirement for the electrolytic capacitor.
Increasing the minimum input capacitance to 680F is recommended for high-performance applications, or
wherever the input source performance is degraded.
The main considerations when selecting input capacitors are the RMS ripple current rating, temperature stability,
and less than 100 m
of equivalent series resistance (ESR).
Regular tantalum capacitors are not recommended for the input bus. These capacitors require a recommended
minimum voltage rating of 2 × (maximum dc voltage + ac ripple). This is standard practice to ensure reliability.
No tantalum capacitors were found with a sufficient voltage rating to meet this requirement.
When the operating temperature is below 0°C, the ESR of aluminum electrolytic capacitors increases. For these
applications, OS-CON, poly-aluminum, and polymer-tantalum types should be considered.
Copyright 2005–2009, Texas Instruments Incorporated
13
Product Folder Link(s): PTH08T240W PTH08T241W
相关PDF资料
PDF描述
PTH08T240WAH 1-OUTPUT DC-DC REG PWR SUPPLY MODULE
PTH08T240WAZT 1-OUTPUT DC-DC REG PWR SUPPLY MODULE
PTH08T250WAST 1-OUTPUT DC-DC REG PWR SUPPLY MODULE
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相关代理商/技术参数
参数描述
PTH08T240WAZ 制造商:Texas Instruments 功能描述:DC/DC Converter
PTH08T240WAZT 功能描述:DC/DC转换器 10A 4.5-14V-Input Wide-Out Adj Pwr Mdl RoHS:否 制造商:Murata 产品: 输出功率: 输入电压范围:3.6 V to 5.5 V 输入电压(标称): 输出端数量:1 输出电压(通道 1):3.3 V 输出电流(通道 1):600 mA 输出电压(通道 2): 输出电流(通道 2): 安装风格:SMD/SMT 封装 / 箱体尺寸:
PTH08T241W 制造商:TI 制造商全称:Texas Instruments 功能描述:10-A, 4.5-V to 14-V INPUT, NON-ISOLATED, WIDE-OUTPUT, ADJUSTABLE POWER MODULE WITH TURBOTRANS
PTH08T241WAD 功能描述:DC/DC转换器 10A 4.5V to 14V Inp Ceramic Cap Version RoHS:否 制造商:Murata 产品: 输出功率: 输入电压范围:3.6 V to 5.5 V 输入电压(标称): 输出端数量:1 输出电压(通道 1):3.3 V 输出电流(通道 1):600 mA 输出电压(通道 2): 输出电流(通道 2): 安装风格:SMD/SMT 封装 / 箱体尺寸:
PTH08T241WAS 功能描述:DC/DC转换器 10A 4.5V to 14V Inp Ceramic Cap Version RoHS:否 制造商:Murata 产品: 输出功率: 输入电压范围:3.6 V to 5.5 V 输入电压(标称): 输出端数量:1 输出电压(通道 1):3.3 V 输出电流(通道 1):600 mA 输出电压(通道 2): 输出电流(通道 2): 安装风格:SMD/SMT 封装 / 箱体尺寸: