MAX3140CEI+T

The MAX3140CEI+T from Analog Devices combines a universal asynchronous receiver-transmitter (UART) with a true fail-safe RS-485/RS-422 transceiver in a compact 28-pin QSOP package. This integration saves board space and microcontroller I/O pins, utilizing a SPI/QSPI/MICROWIRE-compatible serial interface.

The device offers true fail-safe receiver circuitry, ensuring a logic-high output even with open or shorted inputs, eliminating the need for complex termination. It supports software-selectable half- or full-duplex operation, data rate, slew rate, and transmitter/receiver phase control. The RS-485 driver supports data rates up to 10Mbps, with programmable slew rates to minimize EMI. The UART includes an 8-word receive FIFO and supports baud rates from 300 to 230k baud with an external crystal.

Operating from a single +5V supply, the MAX3140CEI+T typically consumes only 645µA with the receiver active, and a hardware-invoked shutdown mode reduces current to 20µA. Its receiver input impedance allows up to 256 transceivers on the bus. This component is suitable for industrial control, HVAC, building control, point-of-sale devices, embedded systems, and intelligent instrumentation applications.

The transceiver is housed in a 28-SSOP package with a width of 3.90mm. It operates within a temperature range of 0°C to 70°C and supports RS232 and RS485 protocols.