FEATURES
• Meets or Exceeds the Requirements of
TIA/EIA-232-F and ITU v.28 Standards
• Operates With 3-V to 5.5-V VCC Supply
• Operates From 250 kbits/s to 1 Mbit/s
• Low Standby Current . . . 1 mA Typical
• External Capacitors . . . 4 × 0.1 mF
• Accepts 5-V Logic Input With 3.3-V Supply
• Designed to Be Interchangeable With Maxim
MAX3237E
• Latch-Up Performance Exceeds 100 mA Per
JESD 78, Class II
• ESD Protection for RS-232 I/O Pins
– ±15 kV – Human-Body Model (HBM)
– ±8 kV – IEC61000-4-2, Contact Discharge
– ±15 kV – IEC61000-4-2, Air-Gap Discharge

APPLICATIONS
• Battery-Powered, Hand-Held, and Portable
Equipment
• PDAs and Palmtop PCs
• Notebooks, Sub-Notebooks, and Laptops
• Digital Cameras
• Mobile Phones and Wireless Devices

DESCRIPTION
The MAX3237E consists of five line drivers, three line receivers, and a dual charge-pump circuit with ±15-kV
ESD protection pin to pin (serial-port connection pins, including GND). The device meets the requirements of
TIA/EIA-232-F and provides the electrical interface between an asynchronous communication controller and the
serial-port connector. The charge pump and four small external capacitors allow operation from a single 3-V to
5.5-V supply. This device operates at data signaling rates of 250 kbit/s in normal operating mode
(MBAUD = GND) and 1Mbit/s when MBAUD = VCC. The driver output slew rate is a maximum of 30 V/ms.
The MAX3237E transmitters are disabled and the outputs are forced into high-impedance state when the device
is in shutdown mode (SHDN = GND) and the supply current falls to less than 1 mA. Also, during shutdown, the
onboard charge pump is disabled; V+ is lowered to VCC, and V– is raised toward GND. Receiver outputs also
can be placed in the high-impedance state by setting enable (EN) high. ROUT1B remains active all the time,
regardless of the EN and SHDN condition.
The MAX3237EC is characterized for operation from 0°C to 70°C. The MAX3237EI is characterized for operation
from –40°C to 85°C.