VMIACC-5595-208工控備件機(jī)器人模塊
安裝技術(shù)
較高的電感器值將有助于消除此問(wèn)題。熱考慮應(yīng)注意確保最壞情況下的輸入電壓和負(fù)載電流條件不會(huì)導(dǎo)致模具溫度過(guò)高。R封裝的典型熱阻為30°C/W，T7封裝的熱阻為50°C/W。但這些數(shù)值會(huì)因安裝技術(shù)（銅面積、氣流等）而異。熱量通過(guò)接線片從封裝傳遞。平均電源電流（包括驅(qū)動(dòng)器電流）為：IIN=4.5mA+DC（ISW/45）ISW=開關(guān)電流DC=開關(guān)占空比開關(guān)功耗由以下公式給出：PSW=（ISW）2（RSW）（DC）RSW=輸出開關(guān)導(dǎo)通電阻管芯的總功耗為電源電流乘以電源電壓之和，加上開關(guān)電源：PD（TOTAL）=（IIN）（VIN）+PSW表面貼裝散熱器可用，可將封裝熱阻降低兩三倍。一家制造商Wakefield Engineering為R封裝提供表面安裝散熱器
電感器的范圍
選擇電感器對(duì)于大多數(shù)應(yīng)用，電感器的范圍為2.2μH至22μH。選擇較低的值以減小電感器的物理尺寸。更高的值允許更多的輸出電流，因?yàn)樗鼈儨p少了功率開關(guān)所看到的峰值電流，功率開關(guān)具有6A限制。較高的值也會(huì)降低輸入紋波電壓并降低鐵芯損耗。在選擇電感器時(shí)，您需要考慮最大負(fù)載電流、鐵芯和銅損耗、允許的組件高度、輸出電壓紋波、EMI、電感器中的故障電流、飽和，當(dāng)然還有成本。建議采用以下程序來(lái)處理這些有點(diǎn)復(fù)雜和沖突的要求。1.假設(shè)升壓轉(zhuǎn)換器的平均電感器電流等于負(fù)載電流乘以VOUT/VIN，并決定電感器是否必須承受連續(xù)過(guò)載條件。例如，如果最大負(fù)載電流下的平均電感器電流為3A，則3A電感器可能無(wú)法承受連續(xù)6A過(guò)載條件。還要注意，升壓轉(zhuǎn)換器沒有短路保護(hù)，在輸出短路條件下，電感器電流僅受輸入電源的可用電流限制。
Installation technology
Higher inductor values will help eliminate this problem. Thermal considerations should take care to ensure that the worst case input voltage and load current conditions do not cause excessive mold temperatures. The typical thermal resistance of R package is 30 ° C/W, and that of T7 package is 50 ° C/W. However, these values will vary depending on the installation technology (copper area, airflow, etc.). Heat is transferred from the package through the lugs. The average power supply current (including driver current) is: IIN=4.5mA+DC (ISW/45) ISW=switching current DC=switching duty cycle Switching power consumption is given by the following formula: PSW=(ISW) 2 (RSW) (DC) RSW=total power consumption of output switch on resistance tube core is the sum of power supply current times power supply voltage, plus switching power supply: PD (TOTAL)=(IIN) (VIN)+PSW surface mount radiator is available, which can reduce the package thermal resistance by two or three times. Wakefield Engineering, a manufacturer, provides surface mounted radiators for R encapsulation
Inductor range
Select inductors For most applications, inductors range from 2.2 μ H to 22 μ H. Select a lower value to reduce the physical size of the inductor. Higher values allow more output current because they reduce the peak current seen by the power switch, which has a 6A limit. Higher values also reduce the input ripple voltage and core loss. When selecting inductor, you need to consider the maximum load current, core and copper loss, allowable component height, output voltage ripple, EMI, fault current in inductor, saturation, and of course cost. The following procedures are recommended to address these somewhat complex and conflicting requirements. 1. Assume that the average inductor current of the boost converter is equal to the load current multiplied by VOUT/VIN, and decide whether the inductor must withstand continuous overload conditions. For example, if the average inductor current at the maximum load current is 3A, the 3A inductor may not be able to withstand a continuous 6A overload condition. Also note that the boost converter has no short-circuit protection. Under the output short-circuit condition, the inductor current is limited only by the available current of the input power supply.
