TIDA-01579高效低波纹输出电源参考设计

电子工程师 2019-05-01 1488

稳压电源

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描述

　　TI公司的TIDA-01579是采用TPS6282x系列等的高效低波纹输出电源参考设计，采用 DCS-Control™拓拓，输出电流高达3A（TPS62823），26/25mΩ内部功率开关，非常低的静态电流4 μA，典型开关频率2.2MHz，可调输出电压从0.6V到4V，1%反馈电压精度，100%占空比，内部有软起动电路，主要用在手持/电池供电设备的POL电源，工厂和建筑物自动化，移动计算和网络卡，固态驱动，数据终端和POL.本文介绍了参考设计TIDA-01579主要特性和指标，框图，电路图，材料清单和PCB设计图。

　　The TPS6282x is an all-purpose and easy to usesynchronous step-down DC-DC converter with a verylow quiescent current of only 4μA. It supplies up to3A output current （TPS62823） from a 2.4V to 5.5Vinput voltage. Based on the DCS-Control™ topologyit provides a fast transient response.

　　The internal reference allows to regulate the outputvoltage down to 0.6V with a high feedback voltageaccuracy of 1% over the junction temperature rangeof -40℃ to 125℃。 The 1，2，3A scalable pin-to-pin andBOM-to-BOM compatible device family can be used with small 470nH inductors.

　　The TPS6282x include an automatically enteredpower save mode to maintain high efficiency down tovery light loads.

　　The device features a Power Good signal and aninternal soft start circuit. It is able to operate in 100%mode. For fault protection， it incorporates a HICCUPcurrent limit as well as a thermal shutdown.

　　The TPS6282x are packaged in a 2 x 1.5mm QFN-8package.

　　参考设计TIDA-01579主要特性：

　　• DCS-Control™ topology

　　• 26/25mΩ Internal Power Switches （TPS62823）

　　• Up to 3A Output Current （TPS62823）

　　• Very Low Quiescent Current of 4 μA

　　• Switching Frequency of typically 2.2 MHz

　　• 1% Feedback Voltage Accuracy （full temp. range）

　　• Enable （EN） and Power Good （PG）

　　• Adjustable Output Voltage from 0.6 V to 4V

　　• 100% Duty-Cycle Mode

　　• Internal Soft-Start Circuitry

　　• Seamless Power Save Mode Transition

　　• Undervoltage Lockout

　　• Active Output Discharge

　　• Cycle-by-Cycle Current Limit

　　• HICCUP Short-Circuit Protection

　　• Over Temperature Protection

　　• Create a Custom Design using the TPS62822 withthe WEBENCH® Power Designer

　　参考设计TIDA-01579应用：

　　• POL supply in Portable/Battery Powered Devices

　　• Factory and Building Automation

　　• Mobile Computing， Networking Cards

　　• Solid State Drive

　　• Data Terminal， Point of Sale

　　• Servers， Projectors， Printers

　　图1.参考设计TIDA-01579框图

　　图2.TPS62822应用电路：2.4V-5.5V 2A电源

　　The point-of-load power-tree on video surveillancesystems is optimized with this reference design. Thisreference design has a high performance on keyparameters such as output voltage accuracy， voltageripple， and thermal dissipation. This high performance is possible with a small board area and low BOM cost.

　　The design operates from a 5-V supply commonlyfound in video doorbells， IP network cameras， andwireless cameras.

　　Video doorbells provide a set of features common to many traditional video surveillance devices. Thisdistinguishing feature demands a unique power design to ensure trouble-free operation from theubiquitous， but widely-varying， AC doorbell supply. To fully utilize an AC source that presents a substantialbottleneck， the power design should be as efficient as possible. This design uses TI’s new synchronousbuck converters and LDOs providing a complete and customizable supply optimized for video doorbells.

　　Our newest converters in QFN and SOT-563 packages allow for a supply design that requires minimalboard space and has a low thermal impact—both of which are needed for smaller form factor electronics.For better compatibility， sequencing is possible for all rails.

　　IP network cameras have increasing image resolution， processing， and illumination requirements while stillfitting in small enclosures. After stepping down from a mid- to high-voltage DC power source such as pluginpower or PoE， the system demands point-of-load conversion with high efficiency and a small footprint.

　　Both efficiency and footprint are important to accommodate small enclosures with， typically， less-thanadequateventilation. This design is optimized for both efficiency and footprint while also providing theflexibility to tailor to more advanced， power-demanding loads， such as a dedicated image recognitionprocessor or 4K video processor.

　　Wireless or battery-powered cameras require high efficiency at both full loads and light loads. Thesecameras typically employ motion detection， human interface， or wireless communications monitoring， orany combination of the three， to minimize time spent in power-hungry states quiescent currents andshutdown currents of subsystems are very important as these standby currents can have significantimpact on overall battery life. The TIDA-01579 reference design has been optimized for this application byutilizing TI’s low-power converters featuring both light load efficiency and shutdown with low Iq. Convertershutdown and low-Iq load switches can be used to cut power to subsystems with less-than-desirablestandby consumption—saving cost and extending battery life.

　　参考设计TIDA-01579主要特性：

　　• 1% Typical output voltage accuracy

　　• High system efficiency to 90% at full load

　　• Voltage ripple 《 60-μV， useful for noise-criticalperipherals

　　• Thermal hot spot is 《 45℃ at full load current

　　• Small PCB real estate

　　• Low BOM cost

　　参考设计TIDA-01579应用：

　　• Video Doorbell

　　• IP Network Camera

　　• Wireless camera

　　• Thermal Imaging Camera