Accession Number : AD0908862

Title :   Techniques for Subnanosecond Logic.

Descriptive Note : Final rept. 7 Jun 71-31 Dec 72,

Corporate Author : TRW SYSTEMS GROUP REDONDO BEACH CA

Personal Author(s) : James, Carl E. ; de Graaf, Kenneth B. ; Carper, Fred S.

Report Date : MAR 1973

Pagination or Media Count : 100

Abstract : This report describes the design and development of a high speed multiplexing/demultiplexing system with digital circuits capable of operating at subnanosecond switching speeds and at serial data rates through 1 Gb/s. The equipment developed consists of a data pattern generator, a high speed 4-to-1 digital multiplexer, a high speed 1-to-4 digital demultiplexer, and an error correlator. The data pattern generator provides a 31-bit PRN data pattern (plus several other data patterns) and serves as a four line, 250 Mb/s per line data source for system test. The multiplexer multiplexes the 250 Mb/s parallel data to a serial data rate of 1 Gb/s. The demultiplexer accepts the 1 Gb/s serial NRZ data and demultiplexes it down to its original four lines at 250 Mb/s per line. The error correlator continually compares the multiplexed and demultiplexed data to detect and display bit errors on a bit-by-bit basis. Because the 1 Gb/s data rate was approximately four times faster than the fastest commercially available logic, special subnanosecond (differential emitter gated) logic circuits were developed in microelectronic hybrid form: latch flip-flop, multiplexer circuit, AND gate, and input/output buffer. These circuits exhibit switching speeds of 200 to 400 psec and propagation delays under 500 psec. The equipment was specifically designed to be a completely variable frequency multiplexing/demultiplexing system and was tested for bit error rate performance at frequencies up through 1 Gb/s.

Descriptors :   (*LOGIC CIRCUITS, MULTIPLEXING), INTEGRATED CIRCUITS, DIGITAL SYSTEMS, INTERFACES, ERRORS, TIMING CIRCUITS, GATES(CIRCUITS), MICROELECTRONICS, BROADBAND, CORRELATORS.

Subject Categories : Electrical and Electronic Equipment

Distribution Statement : APPROVED FOR PUBLIC RELEASE