KSZ9031RNX 查看數據表（PDF） - Microchip Technology

零件编号

产品描述 (功能)

生产厂家

KSZ9031RNX

Gigabit Ethernet Transceiver with RGMII Support

Microchip Technology 

KSZ9031RNX

FIGURE 3-2:

KSZ9031RNX 1000BASE-T BLOCK DIAGRAM - SINGLE CHANNEL

XTAL

CLOCK

GENERATION

TX

SIGNAL

TRANSMIT

BLOCK

ANALOG

HYBRID

BASELINE

WANDER

COMPENSATION

RX

SIGNAL

ECHO

CANCELLER

RX-

ADC

+

OTHER

CHANNELS

SIDE -STREAM

SCRAMBLER

AND

SYMBOL ENCODER

PCS STATE

MACHINES

NEXT

NECXATNCCaEnLcLeElleRr

NEXT Canceller

PAIR SWAP

AND

ALIGN UNIT

LED DRIVER

DESCRAMBLER

+

DECODER

FFE

SLICER

CLOCK AND PHASE

RECOVERY

DFE

AUTO -

NEGOTIATION

PMA STATE

MACHINES

MII

REGISTERS

MII

MANAGEMENT

CONTROL

3.2.1 ANALOG ECHO-CANCELLATION CIRCUIT

In 1000BASE-T mode, the analog echo-cancellation circuit helps to reduce the near-end echo. This analog hybrid circuit

relieves the burden of the ADC and the adaptive equalizer.

This circuit is disabled in 10BASE-T/100BASE-TX mode.

3.2.2 AUTOMATIC GAIN CONTROL (AGC)

In 1000BASE-T mode, the automatic gain control (AGC) circuit provides initial gain adjustment to boost up the signal

level. This pre-conditioning circuit is used to improve the signal-to-noise ratio of the receive signal.

3.2.3 ANALOG-TO-DIGITAL CONVERTER (ADC)

In 1000BASE-T mode, the analog-to-digital converter (ADC) digitizes the incoming signal. ADC performance is essen-

tial to the overall performance of the transceiver.

This circuit is disabled in 10BASE-T/100BASE-TX mode.

3.2.4 TIMING RECOVERY CIRCUIT

In 1000BASE-T mode, the mixed-signal clock recovery circuit together with the digital phase-locked loop is used to

recover and track the incoming timing information from the received data. The digital phase-locked loop has very low

long-term jitter to maximize the signal-to-noise ratio of the receive signal.

The 1000BASE-T slave PHY must transmit the exact receive clock frequency recovered from the received data back to

the 1000BASE-T master PHY. Otherwise, the master and slave will not be synchronized after long transmission. This

also helps to facilitate echo cancellation and NEXT removal.

3.2.5 ADAPTIVE EQUALIZER

In 1000BASE-T mode, the adaptive equalizer provides the following functions:

• Detection for partial response signaling

• Removal of NEXT and ECHO noise

• Channel equalization

Signal quality is degraded by residual echo that is not removed by the analog hybrid because of impedance mismatch.

The KSZ9031RNX uses a digital echo canceler to further reduce echo components on the receive signal.

In 1000BASE-T mode, data transmission and reception occurs simultaneously on all four pairs of wires (four channels).

This results in high-frequency cross-talk coming from adjacent wires. The KSZ9031RNX uses three NEXT cancelers on

each receive channel to minimize the cross-talk induced by the other three channels.

 2016 Microchip Technology Inc.

DS00002117C-page 15

Share Link: