Active Interface Terminator Chip from STMicroelectronics Spans Nine SCSI Signal Lines; Key Features of Nine-Line Chip Include Low Drop-Out Voltage and Power-Down Mode.Business and Technology Editors GENEVA--(BUSINESS WIRE)--Feb. 28, 2002 STMicroelectronics (NYSE NYSE See: New York Stock Exchange : STM (Scanning Tunneling Microscope) A microscope that can image down to the atomic level. An STM uses a piezoelectric tube with a tiny sharp tip at the end that is moved within nanometers of the object being sampled. ) today announced the ST21S07A, a SCSI SCSI in full Small Computer System Interface Once common standard for connecting peripheral devices (disks, modems, printers, etc.) to small and medium-sized computers. SCSI has given way to faster standards, such as Firewire and USB. (Small Computer System Interface) active-terminator chip that integrates a bandgap voltage reference A bandgap voltage reference is a voltage reference circuit widely used in integrated circuits, usually with an output voltage around 1.25 V, close to the theoretical bandgap of silicon at 0 K. The operation principle of bandgap voltage references is quite straightforward. , buffer amplifier An analog device that is typically used for impedance matching and signal isolation. For example, a sound card typically uses buffer amps at most of its input and output ports. and nine switched, precision-trimmed, termination resistors. The ST21S07A is fully compliant with SCSI standards as well as --by accommodating negative-going signals--SCSI-2 and emerging SCSI-3 standards. Other significant features of the ST21S07A include a low drop-out voltage, a power-down mode, hot-plug compatibility, and on-board thermal shutdown. The ST21S07A active-terminator chip accommodates nine signal lines and is intended for use in SCSI devices of any kind, including hard disk drives and read/write CD (Compact Disc) drives. The SCSI-2 and SCSI-3 specifications recommend the use of active termination on single-ended drivers and receivers. The ST21S07A integrates a regulator, comprised of a 1.25V reference and a buffer amplifier, and nine precise, switched 110-ohm (+/-2%) termination resistors. The buffer produces 2.85V, has a 0.5V drop out figure, and can source at least 24mA into each termination resistor when that signal line is active (low). When the driver for a signal line turns off, the terminator chip pulls that signal line to its quiescent voltage of 2.85V. To handle the active negative SCSI signals called for in SCSI-2 and SCSI-3, the buffer can sink up to 200mA. Moreover, to minimize quiescent current consumption, the resistors can be electrically isolated from the bus. Thus, by turning off a transistor on each signal line, the ST21S07A effectively removes itself from the circuit. Among the other advantages that the ST21S07A brings to this function, compared to competitive devices, are increased intrinsic decoupling Decoupling The occurrence of returns on asset classes diverging from their normal pattern of correlation. Notes: Take for example stock and corporate bond returns, which normally rise and fall together. and greater immunity to voltage drops on the Termination Power voltage line; higher noise immunity; and very low quiescent current. An 8-bit-wide SCSI bus arrangement needs two ST21S07A devices on each end of the cable. A 16-bit SCSI bus arrangement takes three ST21S07A devices on each end. The ST21S07A SCSI active-terminator chip comes in an SO-16L or TSSOP-20 package. About STMicroelectronics STMicroelectronics, the world's third largest independent 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 New York Stock Exchange (NYSE) World's largest marketplace for securities. The exchange began as an informal meeting of 24 men in 1792 on what is now Wall Street in New York City. , on Euronext Paris Euronext Paris is France's securities market, formerly known as the Paris Bourse, which merged with the Amsterdam and Brussels exchanges in September 2000 to form Euronext NV, which is the second largest exchange in Europe behind the London Stock Exchange. and on the Milan Stock Exchange Milan Stock Exchange The largest regional stock exchange in Italy, facilitating more than 90% of the country's trading volume. . 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. |
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