Signal transmitting device suited to fast signal transmission

• US 20050088200A1
• Filed: 11/17/2004
• Published: 04/28/2005
• Est. Priority Date: 12/28/1993
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: Akira Yamagiwa, Ryoichi Kurihara, Toshitsugu Takekuma
• Inventors: Kurihara, Ryoichi, Takekuma, Toshitsugu, Yamagiwa, Akira
• Granted Patent: US 7,015,717 B2
• Time in Patent Office: Days
• 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 a circuit block having a driving circuit and an intra-block transmission line for transmitting a signal from the driving circuit, a circuit block 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 the driving and receiving circuit blocks. The inter-block transmission line is terminated by a resistor having substantially the same impedance as the interblock transmission line. The intra-block transmission lines are provided with a resistance element having a resistance substantially equal to a value derived by subtracting 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 terminated at only one end thereof;

a mother board on which the main transmission line is formed;

a first integrated circuit to receive a signal; and

a first connector adapted to connect the mother board to a first daughter board which comprises;

a second integrated circuit to drive the signal, and

a first intra-board line to transmit the signal output from the second integrated circuit to the main transmission line, and a first resistor coupled with the main transmission line and with the first intra-board line, the first resistor having a resistance value to reduce signal reflection between the main transmission line and the first intra-board line.

2. A signal transmitting device according to claim 1, wherein the first resistor has a resistance value to provide impedance matching between the main transmission line and the first intra-board line.

3. A signal transmitting device according to claim 1, wherein the first resistor suppresses signal reflection between the main transmission line and the first intra-board line.

4. A signal transmitting device according to claim 1, wherein the first resistor has a resistance value substantially equal to a value derived by subtracting a half of an impedance of the main transmission line from a predetermined impedance of the first intra-board line.

5. A signal transmitting device according to claim 4, wherein the resistance value is 0.5 times to 1.5 times of the derived value.

6. A signal transmitting device according to claim 1, wherein the impedance of the first intra-board line is higher than the impedance of the main transmission line.

7. A signal transmitting device according to claim 1, wherein the second integrated circuit includes an output circuit of a push-pull type to drive the signal.

8. A signal transmitting device according to claim 1, wherein the second integrated circuit is comprised of an element having a switching function, the element being connected to a power supply and a ground, and wherein the minimum resistance of the element is 50 ohms or less.

9. A signal transmitting device according to claim 1, wherein the second integrated circuit is a memory.

10. A signal transmitting device according to claim 1, wherein the main transmission line is terminated with an element having a resistance substantially equal to an impedance value of the main transmission line itself.

11. A signal transmitting device according to claim 1, further comprising:

a second intra-board line to transmit the signal from the main transmission line to the first integrated circuit,

a second resistor coupled with the main transmission line and with the second intra-board line.

12. A signal transmitting device according to claim 11, wherein the second resistor has a resistance value to provide impedance matching between the main transmission line and the second intra-board line.

13. A signal transmitting device according to claim 11, wherein the second resistor suppresses signal reflection between the main transmission line and the second intra-board line.

14. A signal transmitting device according to claim 11, wherein the second resistor has a resistance value substantially equal to a value derived by subtracting a half of an impedance of the main transmission line from a predetermined impedance of the intra-board line.

15. A signal transmitting device according to claim 14, wherein the resistance value is 0.5 times to 1.5 times of the derived value.

16. A signal transmitting device according to claim 11, wherein the impedance of the second intra-board line is higher than the impedance of the main transmission line.

17. A signal transmitting device according to claim 11, wherein the first integrated circuit is a memory.

18. A signal transmitting device according to claim 11, further comprising a second daughter board, the second daughter board mounting the first integrated circuit, the second intra-board line and the second resistor, and a second connector which connects the mother board and the second daughter board.

57. A signal transmission device according to claim 11, wherein the second resistor has a resistance value to reduce signal reflection between the main transmission line and the second intra-board line.

60. A signal transmitting device according to claim 1, wherein the first resistor is disposed nearer to the first connector than it is to the second integrated circuit.

63. A signal transmitting device according to claim 18, wherein the second resistor is disposed nearer to the second connector than it is to the first integrated circuit.

19. A signal transmitting device comprising:

a first transmission line, terminated at only one end thereof;

a mother board on which the first transmission line formed;

a first integrated circuit to receive a first signal and to drive a second signal; and

a first connector through which a first daughter board is capable of being mounted on the mother board,

wherein the first daughter board comprises;

a second integrated circuit to drive the first signal and to receive the second signal,

a second transmission line to transmit the first and second signals between the second integrated circuit and the first transmission line, and

a first resistor coupled with the first transmission line and with the second transmission line, the first resistor having a resistance value to reduce signal reflection between the first transmission line and the second transmission line.

20. A signal transmitting device according to claim 19, wherein the first resistor has a resistance value to provide impedance matching between the first transmission line and the second transmission line.

21. A signal transmitting device according to claim 19, wherein the first resistor suppresses signal reflection between the first transmission line and the second transmission line.

22. A signal transmitting device according to claim 19, wherein the first resistor has a resistance value substantially equal to a value derived by subtracting a half of an impedance of the first transmission line from a predetermined impedance of the second transmission line.

23. A signal transmitting device according to claim 22, wherein the resistance value is 0.5 times to 1.5 times of the derived value.

24. A signal transmitting device according to claim 19, wherein the impedance of the second transmission line is higher than the impedance of the first transmission line.

25. A signal transmitting device according to claim 19, wherein the second integrated circuit includes an output circuit of push-pull type for driving a signal.

26. A signal transmitting device according to claim 19, wherein the integrated circuit is comprised of an element having a switching function, the element being connected to a power supply and a ground, and wherein the minimum resistance of the element is 50 ohms or less.

27. A signal transmitting device according to claim 19, wherein the second integrated circuit includes a differential input circuit.

28. A signal transmitting device according to claim 27, wherein a reference voltage used in the differential input circuit is supplied from the outside of the second integrated circuit.

29. A signal transmitting device according to claim 19, wherein the second integrated circuit is a memory.

30. A signal transmitting device according to claim 19, wherein the first transmission line is terminated with an element having a resistance substantially equal to an impedance value of the first transmission line itself.

31. A signal transmitting device according to claim 19, further comprising:

a third transmission line to transmit the first and second signals between the first transmission line and the first integrated circuit, and

a second resistor coupled with the first transmission line and with the third transmission line.

32. A signal transmitting device according to claim 31, wherein the second resistor has a resistance value to provide impedance matching between the first transmission line and the third transmission line.

33. A signal transmitting device according to claim 31, wherein the second resistor suppresses signal reflection between the first transmission line and the third transmission line.

34. A signal transmitting device according to claim 31, wherein the second resistor has a resistance value substantially equal to a value derived by subtracting a half of an impedance of the first transmission line from a predetermined impedance of the third transmission line.

35. A signal transmitting device according to claim 34, wherein the resistance value is 0.5 times to 1.5 times of the derived value.

36. A signal transmitting device according to claim 31, wherein the impedance of the third transmission line is higher than the impedance of the first transmission line.

37. A signal transmitting device according to claim 31, wherein the first integrated circuit is a memory.

38. A signal transmitting device according to claim 31, further comprising a second daughter board, the second daughter board mounting the first integrated circuit, the second transmission line, and the first resistor, and

a second connector through which the second daughter board is mounted on the mother board.

58. A signal transmitting device according to claim 31, wherein the second resistor has a resistance value to reduce signal reflection between the first transmission line and the third transmission line.

61. A signal transmitting device according to claim 19, wherein the first resistor is disposed nearer to the first connector than it is to the second integrated circuit.

64. A signal transmitting device according to claim 38, wherein the second resistor is disposed nearer to the second connector than it is to the first integrated circuit.

39. A signal transmitting device comprising:

a first transmission line terminated at only one end thereof;

a mother board on which the first transmission line is formed;

a first integrated circuit to receive a signal; and

a first connector being capable of connecting a first daughter board to the mother board, wherein the first daughter board comprises;

a second integrated circuit to drive the signal,

a second transmission line to transmit the signal output from the second integrated circuit to the first transmission line, and

a first resistor coupled with the first transmission line and with the second transmission line, the first resistor having a resistance value to reduce signal reflection between the first transmission line and the second transmission line.

40. A signal transmitting device according to claim 39, wherein the first resistor has a resistance value to provide impedance matching between the first transmission line and the second transmission line.

41. A signal transmitting device according to claim 39, wherein the first resistor suppresses signal reflection between the first transmission line and the second transmission line.

42. A signal transmitting device according to claim 39 wherein the first resistor has a resistance value substantially equal to a value derived by subtracting a half of an impedance of the first transmission line from a predetermined impedance of the second transmission line.

43. A signal transmitting device according to claim 42, wherein the resistance value is 0.5 times to 1.5 times of the derived value.

44. A signal transmitting device according to claim 39, wherein the impedance of the second transmission line is higher than the impedance of the first transmission line.

45. A signal transmitting device according to claim 39, wherein the second integrated circuit includes an output circuit of push-pull type to drive a signal.

46. A signal transmitting device according to claim 39, wherein the second integrated circuit is comprised of an element having a switching function, the element being connected to a power supply and a ground, and wherein the minimum resistance of the element is 50 ohms or less.

47. A signal transmitting device according to claim 39, wherein the second integrated circuit is a memory.

48. A signal transmitting device according to claim 39, wherein the first transmission line is terminated with an element having a resistance substantially equal to an impedance value of the first transmission line itself.

49. A signal transmitting device according to claim 39, further comprising:

a third transmission line to transmit the signal from the first transmission line to the first integrated circuit, and

a second resistor coupled with the first transmission line and with the third transmission line.

50. A signal transmitting device according to claim 49, wherein the second resistor has a resistance value to provide impedance matching between the first transmission line and the third transmission line.

51. A signal transmitting device according to claim 49, wherein the second resistor suppresses signal reflection between the first transmission line and the third transmission line.

52. A signal transmitting device according to claim 49, wherein the second resistor has a resistance value substantially equal to a value derived by subtracting a half of an impedance of the first transmission line from a predetermined impedance of the third transmission line.

53. A signal transmitting device according to claim 52, wherein the resistance value is 0.5 times to 1.5 times of the derived value.

54. A signal transmitting device according to claim 49, wherein the impedance of the third transmission line is higher than the impedance of the first transmission line.

55. A signal transmitting device according to claim 49, wherein the first integrated circuit is a memory.

56. A signal transmitting device according to claim 49, further comprising a second daughter board, the second daughter board mounting the first integrated circuit, the third transmission line and the second resistor, and

a second connector to connect the second daughter board and the mother board.

59. A signal transmitting device according to claim 49, wherein the second resistor has a resistance value to reduce signal reflection between the first transmission line and the third transmission line.

62. A signal transmitting device according to claim 39, wherein the first resistor is disposed nearer to the first connector than it is to the second integrated circuit.

65. A signal transmitting device according to clan 56, wherein the second resistor is disposed nearer to the second connector than it is to the integrated circuit.

66. A signal transmitting device comprising:

a main transmission line terminated at only one end thereof;

a mother board on which the main transmission line is formed;

a first integrated circuit to receive a signal; and

a first connector adapted to connect the mother board to a first daughter board which comprises;

a second integrated circuit to drive the signal,

a first stub-line to transmit the signal output from the second integrated circuit to the main transmission line, and

a first resistor coupled with the main transmission line and with the first stub-line.

67. A signal transmitting device according to claim 66, wherein the first resistor has a resistance value to provide impedance matching between the main transmission line and the first stub-line.

68. A signal transmitting device according to claim 66, wherein the first resistor suppresses signal reflection between the main transmission line and the first stub-line.

69. A signal transmitting device according to claim 66, wherein the first resistor has a resistance value substantially equal to a value derived by subtracting a half of an impedance of the main transmission line from a predetermined impedance of the first stub-line.

70. A signal transmitting device according to claim 69, wherein the resistance value is 0.5 times to 1.5 times of the derived value.

71. A signal transmitting device according to claim 66, wherein the impedance of the first stub-line is higher than the impedance of the main transmission line.

72. A signal transmitting device according to claim 66, wherein the second integrated circuit includes an output circuit of a push-pull type to drive the signal.

73. A signal transmitting device according to claim 66, wherein the second integrated circuit is comprised of an element having a switching function, the element being connected to a power supply and a ground, and wherein a minimum resistance of the element is 50 ohms or less.

74. A signal transmitting device according to claim 66, wherein the second integrated circuit is a memory.

75. A signal transmitting device according to claim 66, wherein the main transmission line is terminated with an element having a resistance substantially equal to an impedance value of the main transmission line itself.

76. A signal transmitting device according to claim 66, further comprising:

a second stub-line to transmit the signal from the main transmission line to the first integrated circuit, and

a second resistor coupled with the main transmission line and with the second stub-line.

77. A signal transmitting device according to claim 76, wherein the second resistor has a resistance value to provide impedance matching between the main transmission line and the second stub-line.

78. A signal transmitting device according to claim 76, wherein the second resistor suppresses signal reflection between the main transmission line and the second stub-line.

79. A signal transmitting device according to claim 76, wherein the second resistor has a resistance value substantially equal to a value derived by subtracting a half of an impedance of the main transmission line from a predetermined impedance of the stub-line.

80. A signal transmitting device according to claim 79, wherein the resistance value is 0.5 times to 1.5 times of the derived value.

81. A signal transmitting device according to claim 76, wherein the impedance of the second stub-line is higher than the impedance of the main transmission line.

82. A signal transmitting device according to claim 76, wherein the first integrated circuit is a memory.

83. A signal transmitting device according to claim 76, further comprising a second daughter board, the second daughter board mounting the first integrated circuit, the second stub-line and the second resistor, and

a second connector which connects the mother board to the second daughter board.

121. A signal transmitting device according to claim 66, wherein the first resistor has a resistance value to reduce signal reflection between the main transmission line and the first stub-line.

122. A signal transmitting device according to claim 76, wherein the second resistor has a resistance value to reduce signal reflection between the main transmission line and the second stub-line.

127. A signal transmitting device according to claim 66, wherein the first resistor is disposed nearer to the first connector than it is to the second integrated circuit.

130. A signal transmitting device according to claim 83, wherein the second resistor is disposed nearer to the second connector than it is to the first integrated circuit.

84. A signal transmitting device comprising:

a main transmission line terminated at only one end thereof;

a mother board on which the main transmission line is formed;

a first integrated circuit to receive a first signal and to drive a second signal; and

a first connector through which a first daughter board is capable of being mounted on the mother board,

wherein the first daughter board comprises;

a second integrated circuit to drive the first signal and to receive the second signal,

a first stub-line to transmit the first and second signals between the second integrated circuit and the main transmission line, and

a first resistor coupled with the main transmission line and with the first stub-line.

85. A signal transmitting device according to claim 84, wherein the first resistor has a resistance value to provide impedance matching between the main transmission line and the first stub-line.

86. A signal transmitting device according to claim 84, wherein the first resistor suppresses signal reflection between the main transmission line and the first stub-line.

87. A signal transmitting device according to claim 84, wherein the first resistor has a resistance value substantially equal to a value derived by subtracting a half of an impedance of the main transmission line from a predetermined impedance of the first stub-line.

88. A signal transmitting device according to claim 84, wherein the resistance value is 0.5 times to 1.5 times of the derived value.

89. A signal transmitting device according to claim 84, wherein the second integrated circuit includes a push-pull type output circuit to drive a signal.

90. A signal transmitting device according to claim 84, wherein the second integrated circuit is comprised of an element having a switching function, the element being connected to a power supply and a ground, and wherein a minimum resistance of the element is 50 ohms or less.

91. A signal transmitting device according to claim 84, wherein the second integrated circuit includes a differential input circuit.

92. A signal transmitting device according to claim 91, wherein a reference voltage used in the differential input circuit is supplied from the outside of the second integrated circuit.

93. A signal transmitting device according to claim 84, wherein the second integrated circuit is a memory.

94. A signal transmitting device according to claim 84, wherein the main transmission line is terminated with an element having a resistance substantially equal to an impedance value of the main transmission line itself.

95. A signal transmitting device according to claim 84, further comprising:

a second stub-line to transmit the first and second signals between the main transmission line and the first integrated circuit, and

a second resistor coupled with the main transmission line and with the second stub-line.

96. A signal transmitting device according to claim 95, wherein the second resistor has a resistance value to provide impedance matching between the main transmission line and the second stub-line.

97. A signal transmitting device according to claim 95, wherein the second resistor suppresses signal reflection between the main transmission line and the second stub-line.

98. A signal transmitting device according to claim 95, wherein the second resistor has a resistance value substantially equal to a value derived by subtracting a half of an impedance of the main transmission line from a predetermined impedance of the second stub-line.

99. A signal transmitting device according to claim 98, wherein the resistance value is 0.5 times to 1.5 times of the derived value.

100. A signal transmitting device according to claim 95, wherein the impedance of the second stub-line is higher than the impedance of the main transmission line.

101. A signal transmitting device according to claim 95, wherein the first integrated circuit is a memory.

102. A signal transmitting device according to claim 95, further comprising a second daughter board, the second daughter board mounting the first integrated circuit, the first stub-line, and the first resistor, and

a second connector through which the second daughter board is mounted on the mother board.

123. A signal transmitting device according to claim 84, wherein the first resistor has a resistance value to reduce signal reflection between the main transmission line and the first stub-line.

124. A signal transmitting device according to claim 95, wherein the second resistor has a resistance value to reduce signal reflection between the main transmission line and the second stub-line.

128. A signal transmitting device according to claim 84, wherein the first resistor is disposed nearer to the second connector than it is to the second integrated circuit.

131. A signal transmitting device according to claim 102, wherein the second resistor is disposed nearer to the first connector than it is to the first integrated circuit.

133. A signal transmitting device according to claim 84, wherein the impedance of the first stub-line is higher than the impedance of the main transmission line.

103. A signal transmitting device comprising:

a main transmission line terminated at only one end thereof;

a mother board on which the main transmission line is formed;

a first integrated circuit to receive a signal; and

a first connector being capable of connecting a first daughter board to the mother board which comprises;

a second integrated circuit to drive the signal,

a first stub-line to transmit the signal output from the second integrated circuit to the main transmission line, and

a first resistor coupled with the main transmission line and with the first stub-line.

104. A signal transmitting device according to claim 103, wherein the first resistor has a resistance value to provide impedance matching between the main transmission line and the second transmission line.

105. A signal transmitting device according to claim 103, wherein the first resistor suppresses signal reflection between the main transmission line and the first stub-line.

106. A signal transmitting device according to claim 103, wherein the first resistor has a resistance value substantially equal to a value derived by subtracting a half of an impedance of the main transmission line from a predetermined impedance of the first stub-line.

107. A signal transmitting device according to claim 106, wherein the resistance value is 0.5 times to 1.5 times of the derived value.

108. A signal transmitting device according to claim 103, wherein the impedance of the first stub-line is higher than the impedance of the main transmission line.

109. A signal transmitting device according to claim 103, wherein the second integrated circuit includes a push-pull type output circuit to drive a signal.

110. A signal transmitting device according to claim 103, wherein the second integrated circuit is comprised of an element having a switching function, the element being connected to a power supply and a ground, and wherein a minimum resistance of the element is 50 ohms or less.

111. A signal transmitting device according to claim 103, wherein the second integrated circuit is a memory.

112. A signal transmitting device according to claim 103, wherein the main transmission line is terminated with an element having a resistance substantially equal to an impedance value of the main transmission line itself.

113. A signal transmitting device according to claim 103, further comprising:

a second stub-line to transmit the signal from the main transmission line to the first integrated circuit, and

a second resistor coupled with the main transmission line and with the second stub-line.

114. A signal transmitting device according to claim 113, wherein the second resistor has a resistance value to provide impedance matching between the main transmission line and the second stub-line.

115. A signal transmitting device according to claim 113, wherein the second resistor suppresses signal reflection between the main transmission line and the second stub-line.

116. A signal transmitting device according to claim 113, wherein the second resistor has a resistance value substantially equal to a value derived by subtracting a half of an impedance of the main transmission line from a predetermined impedance of the second stub-line.

117. A signal transmitting device according to claim 116, wherein the resistance value is 0.5 times to 1.5 times of the derived value.

118. A signal transmitting device according to claim 113, wherein the impedance of the second stub-line is higher than the impedance of the main transmission line.

119. A signal transmitting device according to claim 113, wherein the first integrated circuit is a memory.

120. A signal transmitting device according to claim 113, further comprising a second daughter board, the second daughter board mounting the first integrated circuit, the second stub-line and the second resistor, and

a second connector to connect the second daughter board to the mother board.

125. A signal transmitting device according to claim 103, wherein the first resistor has a resistance value to reduce signal reflection between the main transmission line and the first stub-line.

126. A signal transmitting device according to claim 113, wherein the second resistor has a resistance value to reduce signal reflection between the main transmission line and the second stub-line.

129. A signal transmitting device according to claim 103, wherein the first resistor is disposed nearer to the first connector than it is to the second integrated circuit.

132. A signal transmitting device according to claim 120, wherein the second resistor is disposed nearer to the second connector than it is to the first integrated circuit.