) x# g3 B, R; i$ O, j# [7 u4 R$ b4 p$ u F+ V Unused pins0 n" P& |9 y" |+ }) r; R4 k2 f3 @0 |
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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.& c& [. U Z9 }" r
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LVDS and TTL outputs - Leave all unused LVDS and TTL outputs open (floating) to conserve power.Do not tie them to ground.4 o( w+ @. N0 N: i* C; Z: j
. Y5 k$ N5 Q G. e8 f6 X! KTTL 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.8 r/ q$ J& p+ U; I: C
