MAX3223

3V 至 5.5V 多通道 RS-232 线路驱动器/接收器

The consists of two line drivers, two 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 A/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. The device operates at data signaling rates up to 250 kbit/s and a maximum of 30-V/µs driver output slew rate.

Flexible control options for power management are available when the serial port is inactive. The auto-powerdown feature functions when FORCEON is low and FORCEOFF\ is high. During this mode of operation, if the device does not sense a valid RS-232 signal, the driver outputs are disabled. If FORCEOFF\ is set low and EN\ is high, both drivers and receivers are shut off, and the supply current is reduced to 1 µA. Disconnecting the serial port or turning off the peripheral drivers causes auto-powerdown to occur. Auto-powerdown can be disabled when FORCEON and FORCEOFF\ are high. With auto-powerdown enabled, the device is activated automatically when a valid signal is applied to any receiver input. The INVALID\ output is used to notify the user if an RS-232 signal is present at any receiver input. INVALID\ is high valid data if any receiver input voltage is greater than 2.7 V or less than –2.7 V or has been between –0.3 V and 0.3 V for less than 30 µs. INVALID\ is low invalid data if the receiver input voltage is between –0.3 V and 0.3 V for more than 30 µs. Refer to Figure 4 for receiver input levels.

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RS-232 Bus-Pin ESD Protection Exceeds ±15 kV Using Human-Body Model HBM

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Meets or Exceeds the Requirements of TIA/EIA-232-F and ITU v.28 Standards

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Operates With 3-V to 5.5-V VCC Supply

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Operates up to 250 kbit/s

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Two Drivers and Two Receivers

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Low Standby Current ...1 µA Typical

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External Capacitors ...4 × 0.1 µF

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Accepts 5-V Logic Input With 3.3-V Supply

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Alternative High-Speed Pin-Compatible Device 1 Mbit/s

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SNx5C3223

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Applications

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Battery-Powered Systems, PDAs, Notebooks, Laptops, Palmtop PCs, and Hand-Held Equipment