6 Detailed Description

6.1 Overview

The TDP2004-Q1 is a four-channel multi-rate linear redriver with integrated signal conditioning. The signal

channels of the device operate independently from one another. Each channel includes a continuous-time

linear equalizer (CTLE) and a linear output driver, which together compensate for a lossy transmission channel

between the source transmitter and the final receiver. The linearity of the data path is specifically designed to

preserve any transmit equalization while keeping receiver equalization effective.

The TDP2004-Q1 can be configured three different ways:

Pin mode – device control configuration is done solely by strap pins. Pin mode is expected to be satisfactory `for

many system implementation needs.

SMBus/I2C Controller mode – device control configuration is read from external EEPROM. When the

TDP2004-Q1 has finished reading from the EEPROM successfully, the device drives the DONEn pin LOW.

SMBus/I2C Target operation is available in this mode before, during, or after EEPROM reading. Note: during

EEPROM reading, if the external SMBus/I2C Controller wants to access TDP2004-Q1 registers, the external

controller must support arbitration. The mode is preferred when software implementation is not desired.

SMBus/I2C Target mode – provides most flexibility. Requires a SMBus/I2C Controller device to configure

TDP2004-Q1 though writing to the Target address.

6.2 Functional Block Diagram

GAIN/SDA

TEST/SCL

EQ1/ADDR1

READ_ENn

DONEn

EQ0/ADDR0

VCC

MODE

PD

Shared Digital Core

Power-On Reset

Always-On 10MHz

GND

RX3P

RX3N

CTLE

Linear

Driver

TX3P

TX3N

RX2P

RX2N

CTLE

Linear

Driver

TX2P

TX2N

Term

Term

Term

Term

RX1P

RX1N

CTLE

Linear

Driver

TX1P

TX1N

RX0P

RX0N

CTLE

Linear

Driver

TX0P

TX0N

Term

Term

Term

Term

TDP2004-Q1

Voltage

Regulator

SEL

6.3 Feature Description

6.3.1 RX Equalization Control Settings

The TDP2004-Q1 receivers feature a continuous-time linear equalizer (CTLE) that applies high-frequency boost

and low-frequency attenuation to help equalize the frequency-dependent insertion loss effects of the passive

channel. The receivers implement two stage linear equalizer for wide range of equalization capability. The

equalizer stages also provide flexibility to make subtle modifications of mid-frequency boost for best EQ gain

TDP2004-Q1

SNLS787 – SEPTEMBER 2025

www.ti.com

12

Submit Document Feedback

Copyright © 2025 Texas Instruments Incorporated

Product Folder Links: TDP2004-Q1