SPI/MICROWIRE-Compatible UART and ±15kV ESD-Protected RS-232 Transceivers with Internal Capacitors

The MAX3110E/MAX3111E combine a full-featured universal asynchronous receiver/transmitter (UART) with ±15kV ESD-protected RS-232 transceivers and integrated charge-pump capacitors into a single 28-pin package for use in space-, cost-, and power-constrained applications. The MAX3110E/MAX3111E also feature an SPI™/QSPI™/MICROWIRE™-compatible serial interface to save additional board space and microcontroller (µC) I/O pins.

A proprietary low-dropout output stage enables the 2-driver/2-receiver interface to deliver true RS-232 performance down to VCC = +3V (+4.5V for MAX3110E) while consuming only 600µA. The receivers remain active in a hardware/software-invoked shutdown, allowing external devices to be monitored while consuming only 10µA. Each device is guaranteed to operate at up to 230kbps while maintaining true EIA/TIA-232 output voltage levels.

The MAX3110E/MAX3111E's UART includes a crystal oscillator and baud-rate generator with software-programmable divider ratios for all common baud rates from 300baud to 230kbaud. The UART features an 8-word-deep receive FIFO that minimizes processor overhead and provides a flexible interrupt with four maskable sources. Two control lines (one input and one output) are included for hardware handshaking.

The UART and RS-232 functions can be used together or independently since the two functions share only supply and ground connections (the MAX3110E/MAX3111E are hardware- and software-compatible with the MAX3100 and MAX3222E).

Applications

* Handheld/Battery-Powered Equipment * Handy Terminals * Industrial Front-Panel Interfaces * Point-of-Sale (POS) Devices * Telecom/Networking Diagnostic Ports

* Integration Reduces Cost and Board Space

* Integrated RS-232 Transceiver and UART in a Single 28–Pin Package

* Guaranteed 230kbps Data Rate

* SPI/QSPI/MICROWIRE-Compatible µC Interface

* Internal Charge-Pump Capacitors—No External Components Required

* Low-Power Operation Reduces Thermal Dissipation

* True RS-232 Operation Down to VCC = +3V (MAX3111E)

* Single-Supply Operation

* +5V (MAX3110E)

* +3.3V (MAX3111E)

* 600µA Supply Current

* 10µA Shutdown Supply Current with Receiver Interrupt Active

* Hardware/Software-Compatible with MAX3100 and MAX3222E