UART Chip with Integrated RS-485 Transceiver - Exar

Exar announced the 8-bit Universal Asynchronous Receiver Transmitter (UART) with integrated RS-485 transceiver device family which supports data rates of up to 8Mbps. Example of  XR19L402/400 applications such:  factory automation, POS (Point-of-Sale) and RS-485 based industrial networking.

Both XR19L402 and XR19L400 devices can operate in four different modes: active, partial sleep, full sleep and Power-Save. Upon power-up, the device is in the active mode where the UART and RS-485 transceiver function normally. In the partial sleep mode, the internal crystal oscillator of the UART, or the charge pump of the RS-485 transceiver, is turned off. In full sleep mode, both the crystal oscillator
and the charge pump are turned off. While the UART is in the sleep mode, the Power-Save mode isolates the core logic from the control signals (chip select, read/write strobes, address and data bus lines) to minimize the
power consumption. The RS-485 receivers remain active in each of these four modes.

The UART Chip with Integrated RS-485 Transceiver devices  operate from a single +3V to 5.5V supply with data rates up to 8Mbps, while meeting all EIA/TIA-485 specifications. The configuration register set is 16550 UART compatible for control, status and data transfer. Also, the devices have 64-bytes of transmit and receive FIFOs, automatic RTS/CTS hardware flow control, automatic Xon/Xoff and special character software flow control, transmit and receive FIFO trigger levels, and a programmable fractional baud rate generator with a prescaler of divide by 1 or 4. Additionally, the devices include an ACP pin which allows the user to shut down the charge pump for the RS-485 drivers. In the UART portion, the Power-Save feature isolates the data bus interface to further reduce power
consumption in the sleep mode.

The UART Chip with Integrated RS-485 Transceiver devices mark Exar’s thirteenth and fourteenth industry-first products in two years. In February 2007, Exar announced the XR20M1172 and XR20V2172; in January 2007, the Company launched the XR19L2×2 8-bit dual-channel UART and RS-232 combination series; in December 2006, the Company launched the XR20M1170 (1.8V) and XR20V2170 I2C/SPI UART with an integrated RS-232 transceiver; in August 2006, Exar introduced the XR17V254 a quad-channel 66MHz PCI 3.0 compliant UART. In June 2006, Exar released the XR16V2×5x series of 16Mbps dual UARTs; in April 2006, Exar launched the single-channel UART and RS-232 combination, the XR19L2xx series; in February 2006, Exar released the XR17V252 a dual-channel 66MHz PCI 3.0 compliant UART; in December 2005,
Exar introduced the industry’s first 1.8V single-channel UART (XR16L570) in 24 and 32-pin QFN packages; in June 2005, Exar added the industry’s smallest UART (XR16L580); lastly, in March 2005, Exar introduced a multi-channel 66MHz PCI 3.0 compliant UART family, the first in this series was an eight-channel (XR17V258) solution.

The UART Chip with Integrated RS-485 Transceiver series supports standard serial port drivers as well as Windows CE drivers. With the availability of software drivers and Exar’s application support line, customers can accelerate their time to market by minimizing driver development, testing and diagnostic procedures.

The XR19L402 UART Chip with Integrated RS-485 is offered in a 48-pin QFN, and is priced at the mid-$4
range in 1,000 piece quantities.

Source: UART Chip with Integrated RS-485 Transceiver - Exar