DS215GHDQG5AZZ01 PLC工控備件
雙極性輸出電壓感測
對于負輸出應用，FB引腳通常保持打開狀態。雙極性輸出電壓感測某些應用受益于感測正和負輸出電壓。典型應用部分中所示的“帶過電壓保護的雙輸出反激轉換器”電路就是一個例子。每個輸出電壓電阻器分壓器如上所述單獨設置。當使用FB和NFB引腳時，R1 VOUT=VREF 1+R2 FB引腳VREF VOUT（）R1 R2 R1=R2–1（）VOUT 1.245 LT1370?F01 APPLICATIO S I FOR ATIO UU W U圖1。正輸出電阻分壓器LT1370用于防止任一輸出超過其設定輸出電壓。例如，在該應用中，如果正輸出比負輸出負載更重，則負輸出將更大，并將調節到期望的設定點電壓。正輸出將略低于其設定點電壓。該技術可防止任何一個輸出在無負載時變為未調節的高電平。
負輸出電阻分壓器
R1–VOUT=VNFB+I 1+NFB（R1）R2 LT1370?F02 NFB PIN VNFR INFB–VOUT（）R1 R2 R1=+30?10–6?v.保證?– 2.48（）（）2.48 R2 OPERATION U 8 LT1370 sn1370 1370fs關機和同步設備具有雙功能S/S引腳，用于關機和同步。該引腳與邏輯電平兼容，可以拉高、連接到VIN或保持浮動以正常工作。S/S引腳上的邏輯低激活關機，將部件的電源電流降至12μA。典型的同步范圍是部件自然開關頻率的1.05到1.8倍，但僅保證在600kHz和800kHz之間。12μs可復位停機延遲網絡可確保部件在收到同步信號時不會停機。當同步頻率高于700kHz時應小心，因為在較高的同步頻率下，用于防止次諧波切換的內部斜率補償的幅度會降低。這種類型的次諧波切換僅在開關的占空比高于50%時發生。
Bipolar output voltage sensing
For negative output applications, the FB pin usually remains open. Bipolar output voltage sensing Some applications benefit from sensing positive and negative output voltages. The circuit of "dual output flyback converter with overvoltage protection" shown in the typical application section is an example. Each output voltage resistor divider is set separately as described above. When FB and NFB pins are used, R1 VOUT=VREF 1+R2 FB pin VREF VOUT() R1 R2 R1=R2 – 1 () VOUT 1.245 LT1370 ? F01 APPLICATIO S I FOR ATIO UU W U Fig. 1. The positive output resistance voltage divider LT1370 is used to prevent any output from exceeding its set output voltage. For example, in this application, if the positive output is heavier than the negative output load, the negative output will be larger and will be adjusted to the desired setpoint voltage. The positive output will be slightly below its set point voltage. This technology can prevent any output from becoming an unregulated high level when there is no load.
Negative output resistance voltage divider
R1–VOUT=VNFB+I 1+NFB（R1）R2 LT1370?F02 NFB PIN VNFR INFB–VOUT（）R1 R2 R1=+30?10–6?v. Ensure that the ? - 2.48 () () 2.48 R2 OPERATION U 8 LT1370 sn1370 1370fs shutdown and synchronization device has a dual function S/S pin for shutdown and synchronization. This pin is compatible with the logic level and can be pulled up, connected to the VIN, or held floating for normal operation. The logic low on the S/S pin activates the shutdown, reducing the power current of the component to 12 μ A. The typical synchronization range is 1.05 to 1.8 times of the component's natural switching frequency, but only between 600kHz and 800kHz. The 12 μ s resettable shutdown delay network ensures that the component does not shut down when it receives a synchronization signal. Be careful when the synchronous frequency is higher than 700kHz, because the amplitude of internal slope compensation used to prevent subharmonic switching will decrease at a higher synchronous frequency. This type of subharmonic switching only occurs when the duty cycle of the switch is higher than 50%.
