MAX3237 Datasheet

• Integrated Features Saves Board Space and Simplifies Design
  • Charge Pump Circuitry Eliminates the Need for a Bipolar ±12V Supply
  • Wide Single-Supply Operation From +3V to +5.5V Supply
  • Always-On Extra Outputs Enable Monitoring of External Devices
• Power Saving Extends Battery Life
  • 1µA Supply Current in Shutdown Mode While Receiver is Active (MAX3237)

• Battery-Powered Equipment
• Handheld Equipment
• High-Speed Modems
• Notebook, Subnotebook, and Palmtop Computers
• Peripherals
• Printers

The MAX3237 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 MAX3237 is guaranteed to run at data rates of 250kbps in normal operating mode and 1Mbps in the MegaBaud™ operating mode.

The MAX3237 has 3 receivers and 5 drivers. Receivers R1 (MAX3237) have extra outputs in addition to their standard outputs. These extra outputs are always active, allowing external devices to be monitored without forward biasing the protection diodes in circuitry that may have V_CC completely removed.