P5200 View Datasheet(PDF) - Conexant Systems

Part Name

Description

Manufacturer

P5200

AccessRunner™ ADSL-USB Modem Device Set

Conexant Systems 

AccessRunner ADSL-USB Modem Device Set Data Sheet

2.3.3 CX20431 AFE Description

The CX20431 Analog Front End (AFE) can support full-rate and G.lite (G.992.2) ADSL modems. The CX20431 AFE

interfaces with the CX20441 LD and the hybrid receive circuitry on the analog side, and with the CX11627 ADDP on the

digital side.

The receive section filters out the unwanted echo and boosts the wanted signal before performing an analog-to-digital (A/D)

conversion.

The transmit section converts digital data to analog signals and performs a smoothing operation before presenting the signals

to the line driver.

Wakeup in G.lite mode is supported by tone detection circuitry integrated in the CX20431 AFE.

The CX20431 operates from a +3.3V supply.

A block diagram of the CX20431 AFE is shown in Figure 2-3.

P5200

USB

Interface

Controller

(UIC)

CX11627

ADSL

Data Pump

(ADDP)

Digital Section

Decimation

Filter

CX20431 Analog Front End (AFE)

Analog Section

ADC

Low Pass

Filter

AGC

Serial

Interface

Reference

Generators

Interpolation

Filter

DAC

SC Filter

AGC

High Pass

Filter

Hybrid

OpAmp

Low Pass

Filter

Figure 2-3. CX20431 AFE Block Diagram

Hybrid

CX20441

Line Driver

(LD)

100427 F2-3_BD_P20431

100427B

Conexant

2-5

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