The MAX3222/MAX3232/MAX3237/MAX3241 transceivers have a proprietary low-dropout transmitter output stage enabling true RS-232 performance from a 3.0V to 5.5V supply with a dual charge pump. The devices require only four small 0.1µF external charge-pump capacitors. The MAX3222, MAX3232, and MAX3241 are guaranteed to run at data rates of 120kbps while maintaining RS-232 output levels. The MAX3237 is guaranteed to run at data rates of 250kbps in the normal operating mode and 1Mbps in the MegaBaud™ operating mode, while maintaining RS-232 output levels. The MAX3222/MAX3232 have 2 receivers and 2 drivers. The MAX3222 features a 1µA shutdown mode that reduces power consumption and extends battery life in portable systems. Its receivers remain active in shutdown mode, allowing external devices such as modems to be monitored using only 1µA supply current. The MAX3222 and MAX3232 are pin, package, and functionally compatible with the industry-standard MAX242 and MAX232, respectively. The MAX3241 is a complete serial port (3 drivers/ 5 receivers) designed for notebook and subnotebook computers. The MAX3237 (5 drivers/3 receivers) is ideal for fast modem applications. Both these devices feature a shutdown mode in which all receivers can remain active while using only 1µA supply current.
The MAX3222, MAX3232, MAX3237, and MAX3241 are low‑dropout RS‑232 transceivers that operate from a 3.0 V to 5.5 V supply and use a dual charge‑pump architecture with only four 0.1 pF external capacitors. They provide true RS‑232 voltage levels, low supply current, and optional shutdown mode where receivers remain active.
The devices are offered in TSSOP and SSOP packages, with ordering information, pin configurations, electrical and timing characteristics, and application notes for notebooks, handheld equipment, high‑speed modems, and battery‑powered designs. The datasheet also covers capacitor selection, shutdown behavior, and protection features.
| Supply voltage range | 3.0 V to 5.5 V |
|---|---|
| Maximum data rate (MAX3222/MAX3232/MAX3241) | 120 kbps |
| Maximum data rate (MAX3237 normal mode) | 250 kbps |
| Maximum data rate (MAX3237 MegaBaud mode) | 1 Mbps |
| Shutdown supply current | < 1 pA |
| Low supply current (typical) | 300 µA (MAX3222/MAX3232/MAX3241) |
The devices operate from 3.0 V to 5.5 V.
In MegaBaud mode the MAX3237 can transmit up to 1 Mbps.
The MAX3222 has two receivers.
Shutdown current is less than 1 pA.