Signal transmitting device, circuit block and integrated circuit suited to fast signal transmission

• US 5,568,063 A
• Filed: 06/07/1995
• Issued: 10/22/1996
• Est. Priority Date: 12/28/1993
• Status: Expired due to Term

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: Hitachi, Ltd.
• Inventors: Takekuma, Toshitsugu, Kurihara, Ryoichi, Yamagiwa, Akira
• Primary Examiner(s): Westin, Edward P.
• Assistant Examiner(s): ROSEEN, RICHARD R
• Application Number:
  US08/476,576
• Time in Patent Office: 503 Days
• Field of Search: 326/30, 326/86
• US Class Current: 326/30
• CPC Class Codes: G06F 13/4072 Drivers or receivers G06F13/4086 takes precedence; for multistate logic circuits H03K19/0002
• CPC Class Codes: G06F 13/4086 Bus impedance matching, e.g. termination
• CPC Class Codes: H04B 3/02 Details
• CPC Class Codes: H04L 25/0278 Arrangements for impedance matching
• CPC Class Codes: H04L 25/028 Arrangements specific to the transmitter end
• CPC Class Codes: H04L 25/0292 Arrangements specific to the receiver end
• CPC Class Codes: H04L 25/0298 Arrangement for terminating transmission lines
• CPC Class Codes: H05K 1/0216 Reduction of cross-talk, noise or electromagnetic interference grounding H05K1/0215
• CPC Class Codes: H05K 1/0237 High frequency adaptations H05K1/0216 takes precedence
• CPC Class Codes: H05K 1/14 Structural association of two or more printed circuits providing electric connection to or between printed circuits H05K1/11, H01R12/00

Abstract

A signal transmitting circuit includes one or more circuit blocks having a driving circuit and an intra-block transmission line for transmitting a signal produced by the driving circuit, one or more circuit blocks having a receiving circuit and an intra-block transmission line for transmitting the signal to said receiving circuit, and a main interblock transmission line for propagating a signal between both of the driving and receiving circuit blocks. Inter-block transmission line is terminated at one or two ends by one or two resistors having substantially the same impedance as the interblock transmission line itself. Each of the intra-block transmission line is provided with a resistance element having a resistance equal to or close to a value derived by subtracting a half of an impedance of the inter-block transmission line from an impedance of the intra-block transmission line, to lower signal amplitude and suppress reflections of a signal at branch points along the main interblock transmission line, thereby enabling a high-speed signal transfer.

Claims

1. A signal transmitting device comprising:

a main transmission line, said main transmission line being terminated at both ends thereof with the same termination voltage; and

a circuit block connected with said main transmission line;

said circuit block comprising;

a driving circuit including an output circuit of a push-pull type for driving a signal,

a receiving circuit including a differential input circuit for receiving a signal,

sub-transmission lines connected to said main transmission line and each of said driving circuit and said receiving circuit, and

a resistor connected between said main transmission line and each of said sub-transmission lines, said resistor having a resistance value to provide impedance matching between the main transmission line and the sub-transmission lines to suppress reflections at branch points between the main transmission line and the sub-transmission lines.

4. A signal transmitting device according to claim 1, wherein the amplitude of a signal transmitted to said main transmission line is lower than that of a signal outputted from said output circuit.

6. A signal transmitting device according to claim 1, wherein a value of a supply voltage supplied to said signal transmitting device, an output characteristic value of said signal driving circuit and an input characteristic value of said input circuit used in the signal transmitting device have the following relations:

space="preserve" listing-type="equation">Vss≦

VoL≦

ViL≦

Vref≦

ViH≦

VoH≦

Vcc

space="preserve" listing-type="equation">Vss≦

VoL≦

ViL≦

Vtt≦

ViH≦

VoH≦

Vcc

where

Vcc;

supply voltage supplied to said output circuit,

VoH;

"High" level prescribed value of said output circuit,

ViH;

"High" level prescribed value of said input circuit,

Vref;

reference voltage of said input circuit,

Vtt;

terminating voltage,

ViL;

"Low" level prescribed value of said input circuit,

VoL;

"Low" level prescribed value of said output circuit, and

Vss;

ground voltage.

8. A signal transmitting device according to claim 1, wherein the amplitude of a signal on said main transmission line is set at a value of 1.5 to 2 times an amplitude which is determined by multiplying an impedance of said main transmission line divided by double an impedance of said sub-transmission line and an amplitude of a signal outputted from said output circuit at its output end.

2. A signal transmitting device comprising:

a main transmission line, said main transmission line being terminated at one end thereof;

a signal driving circuit block connected with said main transmission line,

said signal driving circuit block comprising;

a driving circuit including an output circuit of a push-pull type for driving a signal,

a first sub-transmission line connected to said main transmission line and the output circuit of said driving circuit, and

a resistor connected between said main transmission line and said first sub-transmission line, said resistor having a resistance value to provide impedance matching between the main transmission line and the first sub-transmission line to suppress reflections at a branch point between the main transmission line and the first sub-transmission line; and

a signal receiving block connecting with said main transmission line, said signal receiving block comprising;

a receiving circuit including a differential input circuit for receiving a signal,

a second sub-transmission line connected to said main transmission line and said receiving circuit, and

a resistor connected between said main transmission line and said second sub-transmission line, said resistor having a resistance value to provide impedance matching between the main transmission line and the second sub-transmission line to suppress reflections at a branch point between the main transmission line and second sub-transmission line.

3. A signal transmitting device according to claim 2, wherein said signal driving circuit block is arranged at the opposite side of a termination position of said main transmission line.

5. A signal transmitting device according to claim 3, wherein the amplitude of a signal transmitted to said main transmission circuit is lower than that of a signal outputted from said output circuit.

7. A signal transmitting device according to claim 2, wherein a value of a supply voltage supplied to said signal transmitting device, an output characteristic value of said signal driving circuit and an input characteristic value of said input circuit used in the signal transmitting device have the following relations:

space="preserve" listing-type="equation">Vss≦

VoL≦

ViL≦

Vref≦

ViH≦

VoH≦

Vcc

space="preserve" listing-type="equation">Vss≦

VoL≦

ViL≦

Vtt≦

ViH≦

VoH≦

Vcc

where

Vcc;

supply voltage supplied to said output circuit,

VoH;

"High" level prescribed value of said output circuit,

ViH;

"High" level prescribed value of said input circuit,

Vref;

reference voltage of said input circuit,

Vtt;

terminating voltage,

ViL;

"Low" level prescribed value of said input circuit,

VoL;

"Low" level prescribed value of said output circuit, and

Vss;

ground voltage.

9. A signal transmitting device according to claim 2, wherein the amplitude of a signal on said main transmission line is set at a value of 0.5 to 1.5 times an amplitude which is determined by multiplying an impedance of said main transmission line divided by double impedances of said first and second sub-transmission lines and an amplitude of a signal outputted from said output circuit at its output end.

10. A signal transmitting device comprising:

a main transmission line terminated at one end or both ends thereof with the same termination voltage;

a driving and receiving circuit for driving and receiving a signal;

a stubline for connecting said driving and receiving circuit and said main transmission line; and

a resistor inserted between said main transmission line and said stubline, said resistor having a resistance value to provide impedance matching between the main transmission line and the stubline to suppress reflections at a branch point between the main transmission line and the stubline.

11. A signal transmitting device comprising:

a main transmission line terminated at one end or both ends thereof with the same termination voltage;

a driving circuit for driving a signal;

a stubline for transmitting the signal output from said driving circuit to said main transmission line; and

a resistor inserted between said main transmission line and said stubline, said resistor having a resistance value to provide impedance matching between the main transmission line and the stubline to suppress reflections at a branch point between the main transmission line and the stubline.