The termination resistors, when enabled, are automatically switched in or out to match the transceiver’s protocol selection of RS232 or RS485. The device also features high ESD protection: ±16kV HBM on the transceiver bus pins, when powered off or operating. The LTC2872 can be configured as four RS232 single-ended transceivers or two RS485 differential transceivers, or combinations of both, on shared I/O lines, reducing component count for multiprotocol networks, offering on-the-fly configurability.
The LTC2872 is suitable for a wide range of applications, including software-selectable multiprotocol interface ports, point-of-sale terminals, security cameras, cable repeaters and protocol translators. An optional 1.7V to 5.5V logic supply enables convenient digital interfacing, and an integrated DC/DC boost converter eliminates the need for multiple supplies to drive RS232 levels. Drivers and receivers are independently disabled, leaving them in a high impedance state, consuming only 9µA in a low power shutdown mode.
Aside from automatic termination selection, the LTC2872 provide half- and full-duplex RS485 switching and a logic loopback mode that steers the driver inputs to the receiver outputs for diagnostic self-test and debug. Other protective measures include high ESD of ±4kV or better on all pins, thermal shutdown protection and a full failsafe RS485 receiver for floating, shorted or terminated inputs that eliminates the need for external network biasing resistors and UART lockup.
The LTC2872 is available in 38-pin 5mm x 7mm QFN package and is available in production quantities. Pricing starts at $6.45 each in 1,000 piece quantities.