描述 Description

The MAX3227E consists of one line driver, one line receiver, and a dual charge-pump circuit with ±15-kV IEC 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 1 Mbit/s in normal operating mode and a maximum of 30-V/μs driver output slew rate. This device also features a logic-level output (READY) that asserts when the charge pump is regulating and the device is ready to begin transmitting. The MAX3227E achieves a 1-μA supply current using the auto-powerdown plus feature. This device automatically enters a low-power powerdown mode when the RS-232 cable is disconnected or the drivers of the connected peripherals are inactive for more than 30 s. They turn on again when they sense a valid transition at any driver or receiver input. Auto-powerdown saves power without changes to the existing BIOS or operating system. The MAX3227EC is characterized for operation from 0°C to 70°C. The MAX3227EI is characterized for operation from -40°C to 85°C.

特性 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 at Least 1 Mbit/s
? Low Standby Current . . . 1 μA Typ
? External Capacitors . . . 4 × 0.1 μF
? Accepts 5-V Logic Input With 3.3-V Supply
? Designed to Be Interchangeable With Maxim? MAX3227E
? Latch-Up Performance Exceeds 100 mA Per JESD 78, Class II
? ESD Protection for RS-232 I/O Pins
? ±15 kV — Human-Body Model
? ±8 kV — IEC61000-4-2, Contact Discharge
? ±15 kV — IEC61000-4-2, Air-Gap Discharge

? Auto-Powerdown Plus Feature Automatically Disables Drivers for Power Savings
? Packaged in Plastic Shrink Small-Outline Package
? APPLICATIONS
? Battery-Powered, Hand-Held, and Portable Equipment
? PDAs and Palmtop PCs
? Notebooks, Sub-Notebooks, and Laptops
? Digital Cameras
? Mobile Phones and Wireless Devices