RS-232 Interface Chips from STMicroelectronics Offer Tough ESD Protection and Low Supply Voltage.

Business Editors & Technology Writers

GENEVA--(BUSINESS WIRE)--Nov. 4, 2002

Powered From as Little as 3V, Rugged Driver/Receiver

Chips Move Data At 250-kbit/s

STMicroelectronics (NYSE: STM) today announced two RS-232 interface chips that feature rugged ESD protection, 3V to 5.5V supply voltage, 250-kbit/s minimum data rate, and low-power operation. The two devices, the ST3243E RS-232 transceiver and the ST3232E multiple RS-232 driver/receiver chips, will find suitable application in a wide range of portable and desktop computer equipment including notebook, subnotebook, and palm-top computers; a variety of battery-powered and handheld equipment; and printers and other computer peripherals.

Of the two RS-232 interface chips, the ST3243E includes three drivers and five receivers, while the ST3232E has two drivers and two receivers. To ensure reliable operation, each RS-232 I/O pin of both devices is protected to +/-15 kV using the Human Body Model and +/-8 kV using the IEC 1000-4-2 contact discharge method. Both chips also include a dual charge-pump circuit.

By integrating dual charge pumps and low-dropout transmitters, both devices fully meet EIA/TIA-232 specifications while operating from a 3V to 5.5V supply voltage, eliminating the need for the +/-12V source typically required for other RS-232 interface devices. The charge pumps require only four 0.1-uF capacitors. Other key specifications shared by both the ST3243E and ST3232E include a minimum 250-kbits/s data rate at RS-232 levels, 6V/us slew rate, and as much as a -40(Degree)C to +85(Degree)C operating temperature range. Chips having a 0(Degree)C to 70(Degree)C range are also available.

To conserve power, the ST3243E includes an auto-powerdown function that cuts supply current consumption to as low as 1 uA. During this mode of operation, drivers and receivers are turned off in the absence of signals. Alternatively, only the driver outputs can be disabled. The device is automatically activated when a valid signal appears at any receiver input. The ST3243E is also guaranteed to be able to drive a serial mouse.

For its part, the ST3232E conserves power by limiting supply current to 300uA. It also features a typical output voltage swing of +/-5.4V with all lines loaded, a receiver input voltage range of +/-25V, and a typical propagation delay input to output of 0.15us.

The ST3243E RS-232 transceiver is available in TSSOP-28, SSOP-28, SO-28, and flip-chip packages. The ST3232E RS-232 multiple RS-232 driver and receiver is available in TSSOP-16, SO-16, SO-16 large, and DIP-16 packages. Both chips are available now in production volume quantities.

About STMicroelectronics

STMicroelectronics, the world's third largest semiconductor company, is a global leader in developing and delivering semiconductor solutions across the spectrum of microelectronics applications. An unrivalled combination of silicon and system expertise, manufacturing strength, Intellectual Property (IP) portfolio and strategic partners positions the Company at the forefront of System-on-Chip (SoC) technology and its products play a key role in enabling today's convergence markets. The Company's shares are traded on the New York Stock Exchange, on Euronext Paris and on the Milan Stock Exchange. In 2001, the Company's net revenues were $6.36 billion and net earnings were $257.1 million. Further information on ST can be found at www.st.com.