TI SN65C3221EPW

The SN65C3221E and SN75C3221E contain one line driver, one line receiver, and a dual charge pump circuit with pin-to-pin (serial port connection pins, including GND) ±15kV IEC ESD protection. These devices provide an electrical interface between asynchronous communication controllers and serial port connectors. The charge pump and four small external capacitors support operation from a single 3V to 5.5V supply.

These devices operate at data signaling rates up to 1Mbit/s, with driver output slew rates of 24V/μs to 150V/μs.

Flexible power management control options are available when the serial port is inactive. The auto-powerdown feature is enabled when FORCEON is low and FORCEOFF is high. In this operating mode, the driver outputs are disabled if the device detects no valid RS-232 signal at the receiver inputs. If FORCEOFF is set low and EN is high, both the driver and receiver are shut down, and supply current is reduced to 1μA. Disconnecting the serial port or powering down the peripheral driver triggers an auto-powerdown condition. Auto-powerdown can be disabled by setting both FORCEON and FORCEOFF high. With auto-powerdown enabled, the device automatically activates when a valid signal is applied to the receiver input. The INVALID output indicates to the user whether an RS-232 signal is present at the receiver input. INVALID is high (valid data) if the receiver input voltage is greater than 2.7V or less than -2.7V, or remains between -0.3V and 0.3V for less than 30μs. INVALID is low (invalid data) if the receiver input voltage remains between -0.3V and 0.3V for more than 30μs.

• ESD protection for RS-232 pins
• ±15kV HBM
• ±8kV IEC 61000-4-2 contact discharge
• ±15kV IEC 61000-4-2 air-gap discharge
• Powered by 3V to 5.5V VCC supply
• Data rate up to 1Mbit/s
• Low standby current: 1μA (typical)
• External capacitors: 4×0.1μF
• Accepts 5V logic inputs with 3.3V supply
• RS-232 bus pin ESD protection greater than ±15kV with HBM
• Auto-shutdown automatically disables drivers to reduce power consumption

• Industrial PC
• Wired networking
• Data center and enterprise computing
• Battery-powered systems
• PDA
• Laptop computers
• Portable computers
• Handheld computers
• Handheld devices