CD4050B：的输入输出电平转换问题

wang qiang

Part Number: CD4050B

Tool/software:

在4050B规格书中的第8页和第10页分别看到以上两个图，当vcc是5V（我实际是4.6V）时，输入的高电平必须大于3.5V吗？为什么只有在25°C最小是3.5V，反而在高温（85°C）和低温时（-40°C），最大是3.5V呢？

0 Albert Xu1 2 months ago

Hi,

All of these values should be in the "min".

Please refer to this picture below from an older revision of the document.

0 wang qiang 2 months ago in reply to Albert Xu1

Hi 伟业，你好
还有一个问题需要请教，如上图，vout和Vih与VCC的关系是怎么换算的？比喻VCC为4.6V的时候，怎样知道Vout和Vih的值呢？

0 Albert Xu1 2 months ago in reply to wang qiang

Hi,

These can be estimated to be linear. Please see this FAQ:

0 wang qiang 2 months ago in reply to Albert Xu1

图一

图二

Hi 伟业，你好
我从规格书中看到，上面第一张图片当VCC为5V时，VOUT的高电平最小为4.95V，因为此时的VOUT电平就是VCC经过一个MOS管的压降，
上面第二张图片当VCC为5V时，VOUT为4.5V，这个和第一张图片的Vout电平是不是相矛盾？请帮忙解答

+1 Albert Xu1 2 months ago in reply to wang qiang

Hi,

This middle column is for test conditions where the voltages are forced to the values.

In the first picture, VOH = 4.95 is the min with that specific Vin.

In the second picture, testing conditions are forced to Vout = 4.5, however, there is no mention of Vin.

0 wang qiang 1 month ago in reply to Albert Xu1

嗨，伟业;

我们在应用4050（一共6个通道），只用到其中两个通道，如下图(一），其它没有用到的通道需要怎样处理？悬空还是拉低，或者拉高呢？怎样处理更好？

0 Albert Xu1 1 month ago in reply to wang qiang

Hi,

You cannot leave inputs floating, but outputs can be floating.

You can connect inputs to Vcc or GND, it does not matter.

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