SLLS373M July 1999 – March 2024 SN65LVDS1 , SN65LVDS2 , SN65LVDT2
PRODUCTION DATA
Refer to the PDF data sheet for device specific package drawings
The SN65LVDS1 driver output is a 1.2-V common-mode voltage, with a nominal differential output signal of 350 mV. This 350 mV is the absolute value of the differential swing (VOD = |V+– V–|). The peak-to-peak differential voltage is twice this value, or 700 mV. As mentioned previously, the minimum differential output voltage is 200 mV when the supply voltage is between 2.4 V and 3 V. While 200 mV does not meet the minimum specified voltage for an LVDS-compliant driver, the designer may choose to employ this driver with a lower supply voltage, as long as attention is paid to the channel noise margin.
As we will see shortly, LVDS receiver thresholds are ±100 mV. With these receiver decision thresholds, it is clear that the disadvantage of operating the driver with a lower supply will be noise margin. With fully compliant LVDS drivers and receivers, we would expect a minimum of ~150 mV of noise margin (247-mV minimum output voltage – 100-mV maximum input requirement). If we operate the SN65LVDS1 with a supply in the range of 2.4 V to 3 V, the minimum noise margin will drop to 100 mV (200 mV – 100 mV).