TWI385940B - Area with Programmable Output Voltage Amplitude Level Correction Circuit Area Ethernet Entity Layer Transmitter - Google Patents

Description

Area Ethernet physical layer transmitter with programmable output voltage amplitude level correction circuit

The present invention relates to the design of a regional Ethernet physical layer transmitter, and more particularly to a regional Ethernet physical layer transmitter having a programmable output voltage amplitude level correction circuit.

The development and use of computer networks has increased in an alarming proportion in recent years. Make decision makers, regardless of the size of any type, decide whether or not they need the network to decide which network to use for their business.

Ethernet is one of many networks and has been widely accepted by everyone. Transmission over the network must be in accordance with its individual specifications. The regional Ethernet physical layer transmitter output voltage amplitude level is clearly defined in the IEEE 802.3 specification. The output voltage amplitude level of the 10BASE-T physical layer transmitter must fall between 2.2V and 2.8V. 100BASE- The output voltage amplitude of the T-layer transmitter must fall between 950 mV and 1050 mV, while the output voltage amplitude of the 1000BASE-T physical layer transmitter must fall between 900 mV and 1100 mV.

Referring to Figure 1, it shows a circuit diagram of a conventional area Ethernet physical layer transmitter. The circuit structure of the conventional area Ethernet physical layer transmitter 100 includes a voltage to current converter 1, a bias current circuit 2, and a transmitter 3.

The voltage to current converter 1 includes an external resistor 11, an input terminal 12 and an output terminal 13. The input terminal 12 is input with a reference voltage signal Vref; the output terminal 13 is connected to the bias current circuit 2. The transmitter 3 is connected to a bias current circuit 2. The transmitter 3 has an input terminal 31 and a pair of output terminals 32a, 32b. The output terminals 32a, 32b output an output voltage amplitude level TX+, TX-. When the output voltage amplitude levels TX+, TX- are changed, the output voltage amplitude levels TX+, TX- are adjusted by changing the resistance of the external resistor 11, so that the output voltage amplitude levels TX+, TX- are maintained at a predetermined time. Within the specifications.

After the regional Ethernet physical layer transmitter 100 is commercialized, each component must use a certain production specification, so the resistance of the external resistor 11 must be fixed and cannot be arbitrarily changed. At this time, if the process drifts a little, the output voltage amplitude level TX+, TX- exceeds the specification. As a result, the regional Ethernet physical layer transmitter 100 is not only regarded as a defective product, but also cannot adjust the output voltage amplitude levels TX+, TX- by changing the resistance of the external resistor 11. Furthermore, when the sampling space of the product sample becomes large, since the sample spatial distribution curve of the output voltage amplitude level TX+ and TX- is fixed and unchangeable, the performance of the whole batch of products will be affected if the improvement cannot be performed.

With regard to the patent of the regional Ethernet physical layer transmitter, the U.S. Patent No. 4,755,922 discloses a DC-to-DC converter for an Ethernet transmitter, including a switching control unit, A sense resistor and a converter, although this patent discloses the function of adjusting the output voltage, but does not disclose the use of a switch current type digital to analog converter to correct Circuit technology for output level.

In the U.S. Patent No. 5,644,270, a voltage controlled oscillator including a voltage adjustable resistor includes a resistor-capacitor having a voltage adjustable resistor and a capacitor, and a current source. The technique of this patent is used to tune the time to lock the frequency of the voltage controlled oscillator. Although this patent discloses that it can be used in an Ethernet transmitter, it does not disclose the technique of how to correct the converter.

In the invention of U.S. Patent No. 6,665,347, an output drive circuit for a high speed Ethernet transmitter includes a current drive circuit and a voltage driver. The current drive circuit can drive the transmission line at the first output voltage by the first data generator in the first mode of operation; the voltage driver can drive the transmission line at the second output voltage by the second data generator in the second mode of operation. The first mode of operation and the second mode of operation are independent of each other. Although the output driver circuit of the Ethernet transmitter is disclosed in this patent, the technique of how to correct the transmitter is also not disclosed.

In view of the above, the output voltage amplitude level of the conventional Ethernet physical layer transmitter will change with the process and needs to be adjusted by changing the external resistance. However, after the product is mass-produced, the resistance of the external resistor must be fixed. If the drift occurs after mass production, the output voltage amplitude of the regional Ethernet physical layer transmitter will not change when the output voltage amplitude level exceeds the specification. Overall large number of transmitter output voltage amplitude sample space (Sample Space) distribution curve size Fixed cannot be changed, affecting the performance of the entire batch of products.

Accordingly, it is an object of the present invention to provide a regional Ethernet physical layer transmitter having a programmable output voltage amplitude level correction circuit for adjusting the resistance of an external resistor after the product is mass-produced. The output voltage amplitude of the transmitter is the same as the mass production specification.

Another object of the present invention is to provide a regional Ethernet physical layer transmitter having a programmable output voltage amplitude level correction circuit for varying the sample spatial distribution curve of a large number of transmitter output voltage amplitude levels. In order to achieve the yield standard in mass production.

The technical means adopted by the present invention to solve the problems of the prior art is a regional Ethernet physical layer transmitter having a programmable output voltage amplitude level correction circuit, including a voltage to current converter having an external resistor. a transmitter and an output voltage amplitude level correction circuit.

The output voltage amplitude level correction circuit comprises a switch current type digital to analog converter and a programmable unit connected between the output end of the voltage to current converter and the input end of the transmission circuit, and the programmable unit can generate a preset The bit control signal to the switch current digital to analog converter controls the magnitude of the bias current of the switched current digital to analog converter and adjusts the output voltage amplitude level of the output of the transmitter.

In a preferred embodiment of the present invention, the switched current digital to analog converter includes a basic current source loop for generating a basic current source, and a digital control signal control by a preset bit generated by the programmable unit. for A programmable current source to at least one programmable current source loop of the transmitter. The programmable unit is a programmable register that stores a set parameter value, and the digital control signal of the preset bit is generated by adjusting the parameter value in the programmable register.

Through the technical means adopted by the present invention, the output voltage amplitude level correction circuit in the regional Ethernet physical layer transmitter is designed to have an output voltage caused by a process or other various reasons after mass production. The drift phenomenon of the amplitude level can not be changed by adjusting the resistance of the external resistor. However, the switch current type digital analogy can be changed by adjusting the parameter value in the programmable register of the output voltage amplitude level correction circuit. The magnitude of the bias current generated by the converter, and further adjust the output voltage amplitude level, to ensure that the output voltage amplitude level can be maintained in a certain specification, so that the regional Ethernet physical layer transmitter operates smoothly.

Furthermore, the basic current source generated by the basic current source loop of the switched current digital analog converter and the programmable current source generated by the programmable current source loop are combined with different ratios of nonlinear design, with basic current sources and respective The combination of programmable current sources can determine the resolution of different bias currents to adjust the size of the sample space distribution curve of a large number of transmitter output voltage amplitude levels to meet the yield standard during mass production. In addition, it can be adjusted to a suitable output voltage amplitude level at any time in accordance with various specifications and standards, so that the versatility of the product is greatly increased.

The specific embodiments adopted by the present invention will be The attached drawings are further explained.

Referring to Figure 2, there is shown a circuit block diagram of a preferred embodiment of a regional Ethernet physical layer transmitter having a programmable output voltage amplitude level correction circuit of the present invention. The circuit structure of the regional Ethernet physical layer transmitter 100a is substantially the same as that of the prior art Ethernet physical layer transmitter 100 in the first figure, so the same components are labeled with the same component number. . The regional Ethernet physical layer transmitter 100a includes an output voltage amplitude level correction circuit 4, and the output voltage amplitude level correction circuit 4 includes a switch current type digital to analog converter 41 and a programmable unit 42. .

The switch current type digital to analog converter 41 is connected between the output terminal 13 of the voltage to current converter 1 and the input terminal 31 of the transmitter 3; the programmable unit 42 can generate a digital control signal S of a preset bit to The switch current type digital to analog converter 41 controls the magnitude of the bias current I of the switch current type digital to analog converter 41 by the digital control signal S, and adjusts the output voltage amplitude level output of the output terminal 32 of the transmitter 3 TX+ , TX-.

In the preferred embodiment of the present invention, the programmable unit 42 is a programmable register, and the programmable register stores a set parameter value 421 by adjusting the parameter value 421 in the programmable register. A digital control signal S is generated.

Referring again to Figure 3, there is shown a circuit diagram showing a preferred embodiment of a switched current digital to analog converter. The switch current type digital to analog converter includes a basic current source circuit C0 and four programmable current sources. The circuits C1, C2, C3, and C4 are all supplied with voltage by a voltage source V. The basic current source circuit C0 is used to generate a basic current source I0 for supply to the input terminal 31 of the transmitter 3; the programmable current source circuits C1, C2, C3, C4 can be controlled by the digital control signal S generated by the programmable unit 4. Whether a programmable current source I1, I2, I3, I4 is supplied to the input terminal 31 of the transmitter 3.

The programmable current sources I1, I2, I3, and I4 are determined by the open circuit (current non-conduction) and the path (current conduction) of the switch units SW1, SW2, SW3, and SW4, respectively, on the circuit. When the digital control signal S generated by the programmable unit 4 controls the switch units SW1, SW2, SW3, and SW4 to be open (current is not conducting), only the basic current source I0 can be converted from the switching current digital to analog conversion. The output of the device 41 is a bias current I.

When the digital control signal S generated by the programmable unit 4 controls the switch unit SW1 to be a path (current conduction) and the switch units SW2, SW3, and SW4 are open, the bias current of the switch current type digital to analog converter 41 is output. The size of I is the basic current source I0 plus the programmable current source I1, and other combinations of the bias current I can be deduced by analogy. By adjusting the path or open circuit of the switch units SW1, SW2, SW3, and SW4, the magnitude of the output bias current I can be changed, and the final output output voltage amplitude levels TX+, TX- can be determined.

In this embodiment, although there are only four programmable current source circuits C1, C2, C3, and C4 except for a basic current source circuit C0 in the switched current type digital analog converter, in the practical application, the field is familiar with The skilled person is aware that the number of programmable current source circuits is not limited to this.

Referring to Figure 4, it shows the overall large amount of transmitter output voltage amplitude sample spatial distribution curve. As shown in the figure, the distribution curve after the transmitter output voltage amplitude is normalized for the whole large sample, the sample space here refers to the experimental data samples of all the transmitters as the collection space of the single data. In the figure, the horizontal axis represents the mean value of the output voltage amplitude, the vertical axis represents the probability density function of the output voltage amplitude, and μ represents the mean value of the output voltage amplitude, and the distribution curve position and σ ² represent the standard deviation of the output voltage amplitude, and the output is determined. The magnitude of the voltage amplitude distribution.

The output voltage amplitude distribution curve W1 represents a probability density function distribution curve with a mean of 0 and a standard deviation of 0.2, which is an excellent sample yield distribution curve. The output voltage amplitude distribution curve W2 represents a probability density function distribution curve with a mean of 0 and a standard deviation of 1, which is a standard sample yield distribution curve.

The output voltage amplitude distribution curve W3 represents a probability density function distribution curve with a mean value of 0 and a standard deviation of 5, which is a distribution curve with poor sample yield performance. It is necessary to correct the distribution curve to improve the overall sample space. rate. The output voltage amplitude distribution curve W4 represents a probability density function distribution curve with a mean of -2 and a standard deviation of 0.5, which indicates that the output voltage amplitude of the sample space has a DC deviation, which is an unacceptable sample yield distribution curve, which needs to be The distribution curve is extensively corrected to improve overall sample space yield.

Using multiple programmable current source loops, with different programmable non-linear designs of different programmable current sources, there are more variations in current combinations to determine the resolution of different bias currents I, and the yield performance is not Good output voltage amplitude distribution curve W3, W4 is adjusted to become a good output output voltage Amplitude distribution curves W1, W2.

Referring again to Fig. 5, there is shown a circuit diagram of a preferred embodiment of the present invention. In a preferred embodiment of the present invention, the switch current digital to analog converter 41 is a six-bit switch current digital to analog converter, and the received digital control signal S is also a six-digit digital control signal. . The digital control signal S is sent to the switch current type digital to analog converter 41 to adjust the supply of the programmable current source I1, I2, I3, I4, and the sum of the basic current source I0 determines the magnitude of the bias current I. It is supplied to the conveyor 3 afterwards.

It can be seen from the above embodiments that the regional Ethernet physical layer transmitter with the programmable output voltage amplitude level correction circuit provided by the present invention has industrial utilization value, and therefore the present invention has met the requirements of the patent. The above description is only for the preferred embodiment of the present invention, and those skilled in the art can make other various improvements according to the above description, but these changes still belong to the inventive spirit of the present invention and the following definitions. In the scope of patents.

100‧‧‧Study Area Ethernet Physical Layer Transmitter

100a‧‧‧Regional Ethernet physical layer transmitter

1‧‧‧voltage to current converter

11‧‧‧External resistance

12‧‧‧ input

13‧‧‧ Output

2‧‧‧Butable current circuit

3‧‧‧transmitter

31‧‧‧ input

32a, 32b‧‧‧ output

4‧‧‧Output voltage amplitude level correction circuit

41‧‧‧Switching current digital to analog converter

42‧‧‧programmable unit

421‧‧‧ parameter value

C0‧‧‧Basic current source circuit

C1, C2, C3, C4‧‧‧ programmable current source loop

I‧‧‧Butable current

I0‧‧‧Basic current source

I1, I2, I3, I4‧‧‧ programmable current source

S‧‧‧ digital control signal

SW1, SW2, SW3, SW4‧‧‧ switch unit

TX+, TX-‧‧‧ output voltage amplitude level

V‧‧‧voltage source

Vref‧‧‧reference voltage signal

W1, W2, W3, W4‧‧‧ output voltage amplitude distribution curve

1 is a circuit diagram showing a conventional area Ethernet physical layer transmitter; and FIG. 2 is a comparison showing a regional Ethernet physical layer transmitter having a programmable output voltage amplitude level correction circuit of the present invention. A circuit block diagram of a preferred embodiment; FIG. 3 is a circuit diagram showing a preferred embodiment of a switched current digital to analog converter; and FIG. 4 is a diagram showing an overall large number of transmitter output voltage amplitude sample space divisions. The cloth curve; Fig. 5 is a circuit diagram showing a preferred embodiment of the present invention.

100a‧‧‧Regional Ethernet physical layer transmitter

1‧‧‧voltage to current converter

11‧‧‧External resistance

12‧‧‧ input

13‧‧‧ Output

3‧‧‧transmitter

31‧‧‧ input

32a, 32b‧‧‧ output

4‧‧‧Output voltage amplitude level correction circuit

41‧‧‧Switching current digital to analog converter

42‧‧‧programmable unit

421‧‧‧ parameter value

I‧‧‧Butable current

S‧‧‧ digital control signal

TX+, TX-‧‧‧ output voltage amplitude level

Vref‧‧‧reference voltage signal

Claims (6)

A regional Ethernet physical layer transmitter having a programmable output voltage amplitude level correction circuit, comprising: a voltage to current converter comprising an external resistor, the voltage to current converter having an input end and an output end The input terminal inputs a reference voltage signal; a transmitter has an input end and a pair of output terminals; and an output voltage amplitude level correction circuit includes: a switch current type digital to analog converter connected to the voltage Between the output of the converter and the input of the transmitter, wherein the switch current digital to analog converter includes: a basic current source loop for generating a basic current source to be supplied to the transmitter An input terminal; at least one programmable current source loop, wherein the digital control signal of the preset bit generated by the programmable unit controls whether a programmable current source is supplied to the input end of the transmitter; and a programmable unit can generate a Presetting the digital control signal of the bit to the switch current digital to analog converter to control the current mode of the switch The bias magnitude of the current, and adjusts the output level of the output voltage amplitude of the output end of the conveyor. Programmable output voltage amplitude as described in claim 1 An area Ethernet physical layer transmitter of the level correction circuit, wherein the programmable unit is a programmable register. An area Ethernet physical layer transmitter having a programmable output voltage amplitude level correction circuit as described in claim 2, wherein the programmable register stores a set parameter value by adjusting the parameter The parameter value in the programmable register is used to generate the digital control signal of the preset bit. A regional Ethernet physical layer transmitter having a programmable output voltage amplitude level correction circuit, the area Ethernet physical layer transmitter includes a voltage to current converter having an input end and an output end, a transmitter having an input end and a pair of output terminals and a programmable output voltage amplitude level correction circuit connected between the voltage to current converter and the transmitter, wherein the output voltage amplitude level correction circuit comprises a switching current type digital to analog converter connected between the output end of the voltage to current converter and the input end of the transmitter, wherein the switch current type digital to analog converter comprises: a basic current source circuit And generating a basic current source for supplying to the input end of the transmitter; at least one programmable current source circuit, wherein the digital control signal of the preset bit generated by the programmable unit controls whether a programmable program is supplied a current source to the input end of the transmitter; a programmable unit that generates a preset bit digital control signal to the switch current digital to analog converter to control the switch current digital to analog converter bias The magnitude of the current is adjusted to the output voltage amplitude level of the output of the transmitter. An area Ethernet physical layer transmitter having a programmable output voltage amplitude level correction circuit as described in claim 4, wherein the programmable unit is a programmable register. An area Ethernet physical layer transmitter having a programmable output voltage amplitude level correction circuit according to claim 5, wherein the programmable register stores a set parameter value by adjusting the The parameter value in the programmable register is used to generate the digital control signal of the preset bit.