LVDS Receivers’ Noise Immunity Lends Them To Long Data Runs

Six next-generation low-voltage differential signaling (LVDS) data transmission receivers enable designers to use the higher speeds and lower power consumption of LVDS in cable-connected applications. The six devices- five quad-channel types and one dual-channel receiver-come in SOICs and are the first such devices to exceed the standard common-mode voltage range; in fact, they do so by a factor of three. To comply with the TIA/EIA-644 standard, LVDS transceivers must accommodate ±1V of ground voltage. These new transceivers can recover data over a common-mode range from -2V to 4.5V, which allows up to 3V of ground noise while maintaining the data link. By offering a wider common-mode range, the transceivers can be used over longer distances and in environments with more electrical noise. In addition, the transceivers are the first in the industry to include a terminated fail-safe feature on their inputs, which automatically holds the output lines at a high logic state with no input signal. If the signal is ever removed from the device’s input, the fail-safe feature prevents the device from switching its output when encountering random noise. Once signaling returns, the output resumes tracking its input. This feature is particularly useful in cable-connected applications in which disconnecting a cable can remove the signals. Model SN65LVDS32A is a quad receiver that enables all four drivers at once. The SN65LVDS3486A quad receiver enables two of the four drivers at once. In the SN65LVDT32A and SN65LVDT3486A, integrated termination is added. Models SN65VDS9637A and SN65LVDT9637A are dual receivers without and with integrated termination, respectively.