关于LVDS未使用的输入端
时间：10-02
整理：3721RD
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请教大家，LVDS不使用的输入端大家怎么处理的，悬空么?论坛里有篇文档里面写着要悬空，但是不知道这个说法出自哪里?协议里我草草翻了一下没看见呀~~
现在做前端板子的同学把这些输入端接地了，会不会有问题
Unused pins
LVDS inputs - Leave unused LVDS receiver inputs open (floating) for LVDS receivers unless directed differently by the specific component’s datasheet. Their internal failsafe feature will provide sufficient biasing to put the outputs in a known state. These unused receiver inputs should not be connected to noise sources such as cables or long PCB traces - float them near the pin. LVDS receivers are high-speed, high-gain devices, and only a small amount of noise, if picked up differentially will cause the receiver to respond. This causes false transitions on the output and increases power consumption.
LVDS and TTL outputs - Leave all unused LVDS and TTL outputs open (floating) to conserve power.Do not tie them to ground.
TTL inputs - Tie unused TTL transmitter/driver inputs and control/enable signals to power or ground or in certain cases they may be left open if the datasheet supports this condition. Some devices provide internal pull down (or up) devices to bias the pins. Again, consult the datasheet for information regarding the device’s features. This type of information is typically included in the pin description table.
现在做前端板子的同学把这些输入端接地了，会不会有问题
因為您沒講得很清楚是訊號端（LVDS Side）或邏輯端（Logic Side）的輸入。
- 訊號輸入（LVDS Input）建議懸空（Floating），除非芯片資料有特別指示。
- 邏輯輸入（Logoc Input）建議上拉至邏輯電源（VDD），或是下拉至地（GND），除非芯片資料有特別指示。
Unused pins
LVDS inputs - Leave unused LVDS receiver inputs open (floating) for LVDS receivers unless directed differently by the specific component’s datasheet. Their internal failsafe feature will provide sufficient biasing to put the outputs in a known state. These unused receiver inputs should not be connected to noise sources such as cables or long PCB traces - float them near the pin. LVDS receivers are high-speed, high-gain devices, and only a small amount of noise, if picked up differentially will cause the receiver to respond. This causes false transitions on the output and increases power consumption.
LVDS and TTL outputs - Leave all unused LVDS and TTL outputs open (floating) to conserve power.Do not tie them to ground.
TTL inputs - Tie unused TTL transmitter/driver inputs and control/enable signals to power or ground or in certain cases they may be left open if the datasheet supports this condition. Some devices provide internal pull down (or up) devices to bias the pins. Again, consult the datasheet for information regarding the device’s features. This type of information is typically included in the pin description table.
LVDS应该是COMS工艺的芯片，当输入端悬空时输出端的上电时状态是不确定的，个人觉的输入不用的可以接地当然也可以上拉
接个0R电阻到地吧。应该是可以直接接地的
接个0R电阻到地吧。应该是可以直接接地的
不会有问题，接地意味着没有信号了
悬空就可以了