Driver circuit with self-adjusting impedance matching

Details Driver circuit with self-adjusting impedance matching Driver circuit with self-adjusting impedance matching

1994-05-02

1995-09-05

Hudspeth, David R.

Electronic digital logic circuitry

Signal sensitivity or transmission integrity

Bus or line termination

326 34, 326 83, H03K 1716

Patent

active

054481821

ABSTRACT:
A CMOS driver circuit (20) has a high impedance driver (30) and a low impedance driver (36) connected to the near end of a transmission line (43). The output impedance of the high impedance driver (30) matches the characteristic impedance of the transmission line (43). As a digital signal from the CMOS driver circuit (20) transitions from one logic state to another, the low impedance driver (30) drives the transmission line (43) until a predetermined voltage before the signal reaches its steady state voltage. A sensing circuit (24) senses when the predetermined voltage is reached, and in response, provides a control signal to deactivate the low impedance driver (36). The high impedance driver (30) completes the signal transition. The high impedance driver (30) absorbs the reflected waves from the far end of the transmission line (43), reducing the effects of ringing, and increasing noise immunity.

REFERENCES:
patent: 4707620 (1987-11-01), Sullivan et al.
patent: 4719369 (1988-01-01), Asano et al.
patent: 5095231 (1992-03-01), Sartori et al.
patent: 5107230 (1992-04-01), King
patent: 5134311 (1992-07-01), Biber et al.
patent: 5144165 (1992-09-01), Dhong et al.
patent: 5294845 (1994-03-01), McMahan et al.
patent: 5296756 (1994-03-01), Patel et al.
patent: 5298804 (1994-03-01), Shichinohe
patent: 5332932 (1994-07-01), Runaldue
patent: 5341039 (1994-08-01), Fukumoto
"MC68040 MC68EC040 MC68LC040 Microprocessors User's Manual", Motorola Inc., 1992, pp. 7-68.

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