LMS1487ECNA/NOPB

Interface - Drivers, Receivers, Transceivers

The LMS1487ECNA/NOPB is a monolithic quad differential line driver for RS-422 and RS-485 applications. It can be used in both unbalanced applications and balanced line applications. This device provides logic voltage (VLOGIC) support from +2 to +6 Vdc, allowing it to work with both +3 and +5 V logic. It offers up to 25 mA of local bias current, allowing it to drive up to 7 mA of data rate.

Application Field

The LMS1487ECNA/NOPB can be used in a wide range of interfaces. Video interfaces, such as SMPTE/DVI and HDMI, typically require differential line drivers to transmit digital data. This driver can be used in such applications. The device can also be used in industry standard RS-422 and RS-485 communications applications, such as modems, industrial monitoring and control, or point-of-sale systems.

Working Principle

The device typically consists of two sections: a power section for controlling the currents in the line and the drive section for generating data in the form of output signals. The power section includes a differential amplifier and current sources, a biasing circuit, and a thermal sensor. The differential amplifier is used to balance the input signals and provide sufficient noise immunity to the signal lines. The biasing circuitry provides the power regulation for the line, adjusting the signal levels based on the required line length. The thermal sensor provides thermal protection by controlling the temperature of the power section.

The drive section consists of four independent differential line drivers, each providing a full-duplex transformation of the digital input signals with the capability of level-shifting the output signals. By default, the device is capable of transmitting data at rates up to 25 mA. It is also capable of transmitting data at higher data rates by increasing the bias current.

In summary, the LMS1487ECNA/NOPB is a quad differential line driver that can be used in a wide range of interfaces. It offers logic voltage support from +2 to +6 Vdc and can be used in both unbalanced and balanced line applications. The device includes a power section for controlling the currents in the line and a drive section for generating the output signals. It offers high data rate transmission with up to 25 mA of local bias current, allowing it to drive up to 7 mA of data rate.