The MAX3228/MAX3229 operate from a single +2.35 V to +5.5 V power supply. These devices include a switchover circuit that changes the mode of operation from RS-232-compliant with VCC > +3.1 V to RS-232-compatible with VCC < +3.1 V. The switchover circuitry extends battery life by reducing the supply current requirements. These devices are compatible with multiple logic families. A separate logic supply input, VL, can be connected to a supply as low as +1.65 V. The MAX3228/MAX3229 also feature AutoShutdown, reducing supply current to 1 μA when there is not a valid RS-232 level on the receiver inputs. The MAX3228 features two transmitters and two receivers, and the MAX3229 has one transmitter and one receiver. All devices operate at data rates up to 250 kbps.