MAX3100CEE+

The MAX3100CEE+ is a fully integrated, low-power universal asynchronous receiver/transmitter (UART) with selectable RS-232, RS-422, and RS-485 interfaces. The interface-controller device simplifies system design by providing flexible protocol options and operating parameters without external components. Designers no longer have to decide which interface (RS-232, RS-422, or RS-485) to use for an application, because the MAX3100CEE+ contains all of them in one package.

The MAX3100CEE+\'s flexible operating parameters, including baud rate from 50 bps to 1.5 Mbps, transmit and receive data formats, hardware and software flow control, and a selectable 256-byte FIFO for each receiver and transmitter, make it popular with engineers in many markets. Such applications include, but are not limited to, point-of-sale terminals, medical instrumentation, industrial test equipment, and communications.

The MAX3100CEE+ also offers a low operating voltage of 1.8 V to 5.5 V, low-power shutdown mode, and low-power receive mode to reduce power consumption.

The fundamental function of a UART is to receive serial data and transmit it, so the MAX3100CEE+ includes both an on-chip, TTL-level transmitter and a receiver. The transmitted and received data characters are usually 8 bits long, plus one or two framing bits, depending on the type of interface in use. The two framing bits are the start and stop bits, which frame the data, delineating the beginning and end of a byte of serial data.

The UARTs are designed to be interfaced either to a processor or an application specific integrated circuit (ASIC) that contains a hardware interface, usually an 8-bit parallel port. The interface communicates information to the MAX3100CEE+ about the number of data bits, the number of stop bits, and the type of parity being used in the serial communication. Depending on the application, the MAX3100CEE+ can be programmed to use different types of parity, including odd, even, mark, space, and no parity.

To minimize the complexity of system design and implementation, the MAXX3100CEE+ also supports low-voltage levels, including a selectable standby mode of operation, which reduces the supply current to less than 1 µA.

The MAX3100CEE+ includes programmable baud rate dividers so that it can be used in any system. Futhermore, it offers a selectable 256-byte FIFO for each receiver and transmitter for data buffering, enabling better system performance. And it supports two types of flow control, hardware and software.

Hardware flow control is enabled through the use of two additional signals, Request to Send (RTS) and Clear To Send (CTS). These signals can be used to control the transmission of data so that the sender can be "invited" to send by the recevier. This type of flow control helps to ensure that data is not lost due to buffer overruns or transmission timeouts.

Software flow control is used in applications where hardware flow control is not available or not desired. Software flow control uses predefined characters that are transmitted in the data stream between the transmitter and the receiver to communicate when to stop and start the data transfer.

The MAX3100CEE+ is a powerful and versatile interface-controller solution for applications require high performance serial communication. By providing different interface and operating options along with an integrated low-power operation, designers can significantly reduce their time to market and simplify development.