JP7212950B2 - electrical circuits, electrical connectors, electrical connector assemblies - Google Patents

Description

The present invention relates to electrical circuits and electrical connectors and electrical connector assemblies comprising said electrical circuits.

For high-speed, high-capacity transmissions on the order of or above 10 Gigabits per second (Gbps), electromagnetic compatibility (EMC) is of paramount importance. EMC includes electromagnetic interference susceptibility (EMS) and electromagnetic interference (EMI). EMS means the influence of noise from the outside, and EMI means the emission of noise to the outside.
In the balanced connection method, external noise has almost the same effect on the two signal lines, so the difference between the signals passing through the two signal lines is taken to reduce the effect of external noise. .
It is known that signals are reflected when circuits with different equivalent impedances are connected to each other. Therefore, an impedance matching circuit is provided to match the impedance, thereby preventing signal reflection.
The balanced connection system includes differential mode impedance (also called normal mode impedance), which is the impedance between two signal lines, and common mode impedance, which is the impedance between the signal lines and the outside.
Among them, differential mode impedance is involved in signal transmission. Matching the differential mode impedance can prevent attenuation of the transmitted signal, thus improving EMS.
Also, EMI involves not only the differential mode but also the common mode. Therefore, EMI can be improved by matching not only the differential mode impedance but also the common mode impedance.
That is, EMC is improved by matching the impedances of the two modes.
Patent Document 1 discloses a circuit that matches both the differential mode impedance and the common mode impedance.
Further, Patent Document 2 discloses an equalizer circuit for improving signal reliability in a balanced connection system.

JP 2012-044248 A JP-A-2005-235516

The circuit described in Patent Document 1 cannot be applied when the differential mode equivalent resistance value on the input side is smaller than the differential mode equivalent resistance value on the output side.
Also, the circuit described in Patent Document 2 does not consider impedance matching.
An object of the present invention is to solve such problems.

The electrical circuit includes a first input terminal, a second input terminal, a first output terminal, a second output terminal, a ground terminal, and a second terminal electrically connected between the first input terminal and the ground terminal. A ground resistor, a second ground resistor electrically connected between the second input terminal and the ground terminal, and an input resistor electrically connected between the first input terminal and the second input terminal. a first impedance electrically connected between the first input terminal and the first output terminal; and a second impedance electrically connected between the second input terminal and the second output terminal; a third ground resistor electrically connected between the first output terminal and the ground terminal; a fourth ground resistor electrically connected between the second output terminal and the ground terminal; and the first output an output resistor electrically connected between the terminal and the second output terminal;
Thereby, regardless of the differential mode equivalent resistance values on the input side and the output side, the impedances of the two modes can be matched to improve EMC.
Both the first impedance and the second impedance may be resistors or parallel circuits of resistors and capacitors.
The first impedance capacitor and the second impedance capacitor may have the same capacitance value.
The first ground resistor and the second ground resistor may have the same resistance value R1. The third ground resistor and the fourth ground resistor may have the same resistance value R5. The resistance of the first impedance and the resistance of the second impedance may have the same resistance value R3. R3/R1=√[R03/R01+(R3/R01) ² ]−1 and R3/R5=√[R01/R03+(R3/R03) ² ]−1 and R3/r2=√[Z2/ Z1+(R3/Z1) ² ]−1 and R3/r4=√[Z1/Z2+(R3/Z2) ² ]−1 (where r2=R1·R2/(2·R1+R2), r4=R5· R4/(2・R5+R4), Z1=R01・R02/(2・R01+R02), Z2=R03・R04/(2・R03+R04), R01=2・Wc1, R02=4・Wd1・Wc1/(4・Wc1 −Wd1), R03=2·Wc2, R04=4·Wd2·Wc2/(4·Wc2−Wd2), R2 is the resistance value of the input side resistor, R4 is the resistance value of the output side resistor, and Wc1 is , a common-mode equivalent resistance value of an input-side external circuit electrically connected to the first input terminal and the second input terminal, Wd1 is a differential-mode equivalent resistance value of the input-side external circuit, and Wc2 is the first output. The common-mode equivalent resistance value Wd2 of the output-side external circuit electrically connected to the terminal and the second output terminal may represent the differential-mode equivalent resistance value of the output-side external circuit.
A common-mode equivalent resistance value of the electric circuit viewed from an input-side external circuit electrically connected to the first input terminal and the second input terminal may match the common-mode equivalent resistance value of the input-side external circuit. good. A differential mode equivalent resistance value of the electric circuit viewed from the input side external circuit may match a differential mode equivalent resistance value of the input side external circuit. A common-mode equivalent resistance value of the electric circuit viewed from an output-side external circuit electrically connected to the first output terminal and the second output terminal may match the common-mode equivalent resistance value of the output-side external circuit. good. A differential mode equivalent resistance value of the electric circuit viewed from the output side external circuit may match a differential mode equivalent resistance value of the output side external circuit.
This makes it possible to improve EMC since the impedances of the two modes are matched.
The electrical connector may comprise the electrical circuitry described above.
The electrical connector assembly has a first electrical connector having a first contact and a second contact, a third contact, and a fourth contact, and is connected to the first electrical connector to connect the third electrical connector. A second electrical connector may be provided, wherein a contact is in contact with and electrically connected to the first contact, and the fourth contact is in contact with and electrically connected to the second contact. The electrical circuit described above may be formed by connecting the first electrical connector and the second electrical connector.
The first electrical connector may include the first ground resistor, the second ground resistor, and the input resistor. The second electrical connector may include the third ground resistor, the fourth ground resistor, and the output side resistor. The first impedance may be constituted by an equivalent impedance of a circuit including the first contact and the third contact. The second impedance may be constituted by an equivalent impedance of a circuit including the second contact and the fourth contact.
As a result, signal attenuation can be suppressed.

An electrical circuit diagram showing an exemplary electrical circuit 10A. FIG. 4 is an electrical schematic diagram showing an exemplary electrical connector assembly 80. FIG. An electrical circuit diagram showing an exemplary electrical circuit 10B.

As shown in FIG. 1, the electric circuit 10A has a pair of input terminals 21, 22, a pair of output terminals 23, 24, a ground terminal 25, and eight resistors 31-38.
The input terminals 21 and 22 are electrically connected to a balanced connection type electric circuit (for example, an electric circuit formed on a substrate such as a paddle card substrate, a card edge substrate, a flexible substrate, or a signal cable).
The output terminals 23 and 24 are electrically connected to a balanced connection type electric circuit (for example, an electric circuit formed on a substrate such as a paddle card substrate, a card edge substrate, a flexible substrate, or a signal cable).
The ground terminal 25 is electrically connected to ground or earth.
The resistor 31 has a resistance value of R1 and is electrically connected between the input terminal 21 and the ground terminal 25 . The resistor 32 has the same resistance value R1 as the resistor 31 and is electrically connected between the input terminal 22 and the ground terminal 25 . The resistor 33 has a resistance value of R5 and is electrically connected between the output terminal 23 and the ground terminal 25 . The resistor 34 has the same resistance value R5 as the resistor 33 and is electrically connected between the output terminal 24 and the ground terminal 25 . The resistor 35 has a resistance value of R2 and is electrically connected between the input terminal 21 and the input terminal 22 . The resistor 36 has a resistance value of R4 and is electrically connected between the output terminals 23 and 24 . The resistor 37 has a resistance value of R3 and is electrically connected between the input terminal 21 and the output terminal 23 . The resistor 38 has the same resistance value R3 as the resistor 37 and is electrically connected between the input terminal 22 and the output terminal 24 .

In the electric circuit 10A, differential mode impedance and Match the common mode impedance to each other.

Let Wd1 be the differential mode impedance of the input side external circuit, Wc1 be the common mode impedance of the input side external circuit, Wd2 be the differential mode impedance of the output side external circuit, and Wc2 be the common mode impedance of the output side external circuit. When all are met, both the differential mode impedance and the common mode impedance are matched.

(Condition 1) R3/R1=√(R01·R03+R3 ² )/R01−1,
(Condition 2) R3/R5=√(R01·R03+R3 ² )/R03−1,
(Condition 3) R3/r2=√(Z1·Z2+R3 ² )/Z1−1,
(Condition 4) R3/r4=√(Z1·Z2+R3 ² )/Z2−1.
however,
r2=R1.R2/(2.R1+R2),
r4=R5.R4/(2.R5+R4),
Z1=R01*R02/(2*R01+R02),
Z2=R03·R04/(2·R03+R04),
R01=2·Wc1,
R02=4·Wd1·Wc1/(4·Wc1−Wd1),
R03=2·Wc2,
R04=4.Wd2.Wc2/(4.Wc2-Wd2).

In order for R1 to R5 satisfying the above conditions 1 to 4 to exist, the following conditions must be satisfied.
(Condition 5) R01·R03+R3 ² >R01 ²
(Condition 6) R01·R03+R3 ² >R03 ²
(Condition 7) Z1・Z2+R3 ² >Z1 ²
(Condition 8) Z1・Z2+R3 ² >Z2 ²

From conditions 5 and 6, R3>√(R0max·ΔR0). However, R0max indicates the larger one of R01 and R03, and ΔR0 indicates the absolute value of the difference between R01 and R03.
From conditions 7 and 8, R3>√(Zmax·ΔZ). However, Zmax indicates the larger one of Z1 and Z2, and ΔZ indicates the absolute value of the difference between Z1 and Z2.

That is, not only when R01 is smaller than R03, but also when R01 is larger than R03, it is possible to match the impedances of the two modes by setting the values of R1 to R5 so as to satisfy the above conditions. can.

Since the resistors 37 and 38 are inserted in the signal transmission path, the larger R3 is, the greater the attenuation of the signal. Therefore, it is preferable to set the value of R3 to a value as small as possible within the range that satisfies the above conditions.

As shown in FIG. 2, the electrical connector assembly 80 has two electrical connectors 81,82.
The electrical connector 81 has a pair of input terminals 21 , 22 , a ground terminal 25 , three resistors 31 , 32 , 35 and two contacts 61 , 62 . The contact 61 has internal resistance and is electrically connected to the input terminal 21 . Contact 62 has an internal resistance and is electrically connected to input terminal 22 .
The electrical connector 82 has a pair of output terminals 23 , 24 , a ground terminal 25 , three resistors 33 , 34 , 36 and two contacts 63 , 64 . The contact 63 has internal resistance and is electrically connected to the output terminal 23 . Contact 64 has an internal resistance and is electrically connected to output terminal 24 .

When the electrical connectors 81 and 82 are connected, the contacts 61 and 63 come into contact and are electrically connected, and the contacts 62 and 64 come into contact and are electrically connected. A series circuit formed by electrically connecting the internal resistance of the contact 61 and the internal resistance of the contact 63 in series corresponds to the resistor 37 of the electric circuit 10A described above. Similarly, a series circuit formed by electrically connecting the internal resistance of the contact 62 and the internal resistance of the contact 64 in series corresponds to the resistor 38 of the electric circuit 10A described above. As a result, a circuit corresponding to the electric circuit 10A described above is formed as a whole.

As described above, since the resistors 37 and 38 are inserted in the signal transmission path, they attenuate the signal. The same applies to the internal resistances of the contacts 61-64. By using the internal resistance of the contacts 61 to 64 as the resistors 37 and 38, the resistance inserted in the signal transmission path can be reduced, thereby suppressing signal attenuation.

If the equivalent resistance value of the series circuit of the internal resistance of the contact 61 and the internal resistance of the contact 63 is smaller than the value of R3 that satisfies the above conditions, between the contact 61 and the input terminal 21 and between the contact 61 and the input terminal 21 A resistor may be interposed between at least one of the contact 63 and the output terminal 23 to increase the equivalent resistance value. The same is true for the contacts 62 and 64 as well.

Needless to say, instead of providing a portion of the electrical circuit 10A in the electrical connector 81 and the electrical connector 82 in this manner, the entire electrical circuit 10A is provided in either the electrical connector 81 or the electrical connector 82. may
Alternatively, both the electrical connector 81 and the electrical connector 82 may be provided with the electrical circuit 10A.
Also, the electrical circuit 10A may be provided on a substrate to which the electrical connector is attached instead of being provided on the electrical connector.

As shown in FIG. 3, electrical circuit 10B is similar to electrical circuit 10A described above, but additionally includes two capacitors 47,48.
Capacitor 47 is electrically connected in parallel with resistor 37 between input terminal 21 and output terminal 23 .
Capacitor 48 is electrically connected in parallel with resistor 38 between input terminal 22 and output terminal 24 .

A parallel circuit of a resistor and a capacitor inserted in the signal transmission path functions as an equalizer circuit and can improve the eye pattern. This improves signal quality.

Instead of providing an equalizer circuit for improving the eye pattern separately from the circuit for impedance matching, the resistors 37 and 38 are used for both the circuit for impedance matching and the equalizer circuit, thereby improving signal transmission. Since the resistance inserted in the path can be reduced, signal attenuation can be suppressed.

The embodiment described above is an example for facilitating understanding of the present invention. The present invention is not limited thereto and includes various modifications, changes, additions or omissions without departing from the scope defined by the appended claims. This can be easily understood by those skilled in the art from the above description.

10A, 10B electric circuit 21, 22 input terminals 23, 24 output terminals 25 ground terminals 31, 32, 33, 34, 35, 36, 37, 38 resistors 47, 48 capacitors 61, 62, 63, 64 contacts, 80 electrical connector assemblies, 81, 82 electrical connectors.

Claims (9)

having a first input terminal, a second input terminal, a first output terminal, a second output terminal, and a ground terminal;
a first grounding resistor electrically connected between the first input terminal and the grounding terminal;
a second grounding resistor electrically connected between the second input terminal and the grounding terminal;
an input-side resistor electrically connected between the first input terminal and the second input terminal;
a first impedance electrically connected between the first input terminal and the first output terminal;
a second impedance electrically connected between the second input terminal and the second output terminal;
a third ground resistor electrically connected between the first output terminal and the ground terminal;
a fourth ground resistor electrically connected between the second output terminal and the ground terminal;
An electric circuit comprising an output resistor electrically connected between the first output terminal and the second output terminal. Both the first impedance and the second impedance are resistances,
2. The electrical circuit of claim 1. Both the first impedance and the second impedance are parallel circuits of a resistor and a capacitor,
2. The electrical circuit of claim 1. The first impedance capacitor and the second impedance capacitor have the same capacitance value,
4. The electrical circuit of claim 3. the first grounding resistor and the second grounding resistor have the same resistance value R1,
the third grounding resistor and the fourth grounding resistor have the same resistance value R5,
The resistance of the first impedance and the resistance of the second impedance have the same resistance value R3,
R3/R1=√(R01·R03+R3 ² )/R01−1, and
R3/R5=√(R01·R03+R3 ² )/R03−1, and
R3/r2=√(Z1·Z2+R3 ² )/Z1−1, and
R3/r4=√(Z1・Z2+R3 ² )/Z2−1 (however,
r2=R1.R2/(2.R1+R2),
r4=R5.R4/(2.R5+R4),
Z1=R01*R02/(2*R01+R02),
Z2=R03·R04/(2·R03+R04),
R01=2·Wc1,
R02=4·Wd1·Wc1/(4·Wc1−Wd1),
R03=2·Wc2,
R04=4·Wd2·Wc2/(4·Wc2−Wd2),
R2 is the resistance value of the input side resistor;
R4 is the resistance value of the output side resistor;
Wc1 is a common-mode equivalent resistance value of an input-side external circuit electrically connected to the first input terminal and the second input terminal;
Wd1 is the differential mode equivalent resistance value of the input side external circuit;
Wc2 is a common-mode equivalent resistance value of an output-side external circuit electrically connected to the first output terminal and the second output terminal;
Wd2 represents the differential mode equivalent resistance value of the output side external circuit. ) is
5. The electrical circuit of any one of claims 2-4. A common-mode equivalent resistance value of the electric circuit viewed from an input-side external circuit electrically connected to the first input terminal and the second input terminal matches a common-mode equivalent resistance value of the input-side external circuit,
A differential mode equivalent resistance value of the electric circuit viewed from the input side external circuit matches a differential mode equivalent resistance value of the input side external circuit,
A common-mode equivalent resistance value of the electric circuit viewed from an output-side external circuit electrically connected to the first output terminal and the second output terminal matches a common-mode equivalent resistance value of the output-side external circuit,
A differential mode equivalent resistance value of the electric circuit viewed from the output side external circuit matches a differential mode equivalent resistance value of the output side external circuit.
5. The electrical circuit of any one of claims 1-4. An electrical connector comprising the electrical circuit of any one of claims 1 to 6. a first electrical connector having a first contact and a second contact;
It has a third contact and a fourth contact, and is connected to the first electrical connector so that the third contact is in contact with the first contact and is electrically connected, and the fourth contact is connected to the second electrical connector. a second electrical connector electrically connected in contact with the contact;
The electrical circuit according to any one of claims 1 to 6 is formed by connecting the first electrical connector and the second electrical connector.
electrical connector assembly. the first electrical connector includes the first grounding resistor, the second grounding resistor, and the input side resistor;
the second electrical connector includes the third grounding resistor, the fourth grounding resistor, and the output side resistor;
the first impedance is constituted by an equivalent impedance of a circuit including the first contact and the third contact;
the second impedance is configured by an equivalent impedance of a circuit including the second contact and the fourth contact;
9. The electrical connector assembly of Claim 8.

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