This part is a kind of semiconductor called MAX3311EUB.

Function of this product has 460kbps / 1A Supply Current / RS-232-Compatible Transceivers in MAX.

Manufacturers : Maxim

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Some of the text within the PDF file :

19-1901; Rev 0; 2/01 460kbps, 1µA Supply Current, RS-232-Compatible Transceivers in µMAX General Description The MAX3311/MAX3313 are low-power, +5V EIA/TIA232-compatible transceivers. Both devices have one transmitter and one receiver. The transceivers have a proprietary low-dropout transmitter output stage enabling RS-232-compatible operation from a +5V supply with a single inverting charge pump. These devices require only three 0.1µF capacitors and will run at data rates up to 460kbps while maintaining RS-232-compatible output levels. The MAX3311 features a 1µA shutdown mode. In shutdown the device turns off the charge pump, pulls V- to ground, and the transmitter output is disabled. The MAX3313 features an INVALID output that asserts high when an active RS-232 cable signal is conne [ ... ]

MAX3311EUB PDF Datasheet Download