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Texas Instruments ONEt4291VA Data Sheet / User's Guide

Summary

The ONET4291VA is a versatile, high-speed multi-rate VCSEL driver engineered for demanding fiber optic transmission applications up to 4.25 Gbps. This compact component streamlines design by offering digital control over both modulation and bias currents through an integrated two-wire interface. The manual provides comprehensive details on its advanced architecture, including automatic power control (APC) loop technology and built-in laser safety features. It is essential for engineers developing robust SFP/SFF modules or Gigabit Ethernet transmitters needing reliable performance in thermally fluctuating environments (-40°C to 85°C).

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查询ONET4291VA供应商

ONET4291VA

www.ti.com

SLLS674–SEPTEMBER

GBPS TO 4.25 GBPS MULTI-RATE VCSEL DRIVER

FEATURES Operating Temperature –40°C to 85°C

Multi-Rate Operation from Gbps Up Small Footprint Surface Mount mm mm,

To 4.25 Gbps 20-Pin QFN Package

2-Wire Digital Interface

APPLICATIONS

Digitally Selectable Modulation Current

Multirate SFP/SFF Modules•

Digitally Selectable Bias Current

1.0625 Gbps, 2.125 Gbps, and 4.25 Gbps Fibre

Automatic Power Control (APC) Loop

Channel Transmitters

Supports Transceiver Management

Gigabit Ethernet Transmitters

System (TMS)

Includes Laser Safety Features

Analog Temperature Sensor Output

Single 3.3-V Supply

DESCRIPTION

The ONET4291VA is versatile high-speed multi-rate VCSEL driver for fiber optic applications with data rates up

to 4.25 Gbps.

The device provides 2-wire interface which allows digital control of the modulation and bias currents,

eliminating the need for of external components.

The ONET4291VA includes an integrated automatic power control loop as well as circuitry to support laser safety

and transceiver management systems.

The part is available in small footprint mm mm 20-pin QFN package and it requires single 3.3-V supply.

This power efficient multi-rate VCSEL driver is characterized for operation from –40°C to 85°C ambient

temperature.

BLOCK DIAGRAM

simplified block diagram of the ONET4291VA is shown in Figure 1.

This compact, low power 1-Gbps to 4.25-Gbps multi-rate VCSEL driver consists of high-speed current

modulator, modulation current generator, power-on reset circuitry, 2-wire interface and control logic block,

bias current generator and automatic power control loop, and an analog reference block.

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas

Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

PRODUCTION DATA information is current as of publication date. Copyright 2005, Texas Instruments Incorporated

Products conform to specifications per the terms of the Texas

Instruments standard warranty. Production processing does not

necessarily include testing of all parameters.

Page Summary Contents For Texas Instruments ONEt4291VA Data Sheet / User's Guide

Page 1 查询ONET4291VA供应商 ONET4291VA www.ti.com SLLS674–SEPTEMBER GBPS TO 4.25 GBPS MULTI-RATE VCSEL DRIVER FEATURES Operating Temperature –40°C to 85°C Multi-Rate Operation from Gbps Up Small Footprint Surface...
Page 2 ONET4291VA www.ti.com SLLS674–SEPTEMBER GND VCC DOUT+ Power-On Reset al ef er en ce RESET DOUT− Limiting Gain Stage High-Speed Current Modulator MODR Modulation Current Generator RESET MODC MODR ENA S...
Page 3 ONET4291VA www.ti.com SLLS674–SEPTEMBER HIGH-SPEED CURRENT MODULATOR The data signal is applied to the high-speed current modulator by means of the input signal pins DIN+/DIN–, which provide on-chip d...
Page 4 ONET4291VA www.ti.com SLLS674–SEPTEMBER 11 Bit Shift Register 8 Bits Data 3 Bits Addr 8 Bit Register Control Functions (6 Bit) 000START Unused (2 Bit) Start/Stop Detector Logic STOP 8 Bit Register Mod...
Page 5 ONET4291VA www.ti.com SLLS674–SEPTEMBER START STOP1 DTAR DTAHI DTAWT STRTHLD DTASTP CLKR DTAHLD CLKF STOPSTP CLKHI Figure 3. 2-Wire Interface Timing Diagram Table 1. 2-Wire Interface Timing PARAMETER ...
Page 6 ONET4291VA www.ti.com SLLS674–SEPTEMBER Table 3. Register (001b) Mapping address (001b) bit bit bit bit bit bit bit bit MODC7 MODC6 MODC5 MODC4 MODC3 MODC2 MODC1 MODC0 Table 4. Register (010b) Mapping...
Page 7 ONET4291VA www.ti.com SLLS674–SEPTEMBER BIAS CURRENT GENERATION AND APC LOOP The bias current generation and APC loop are controlled by means of the 2-wire interface. In open loop operation, selected ...
Page 8 ONET4291VA www.ti.com SLLS674–SEPTEMBER 2. Setting the modulation current to zero. 3. Asserting and latching the FLT pin. Fault recovery is performed by the following procedure: 1. The disable pin DIS...
Page 9 ONET4291VA www.ti.com SLLS674–SEPTEMBER TERMINAL FUNCTIONS (continued) TERMINAL TYPE DESCRIPTION NO. NAME MONP Analog-out Photodiode current monitor. Sources 50% replica of the photodiode current. Con...
Page 10 ONET4291VA www.ti.com SLLS674–SEPTEMBER DC ELECTRICAL CHARACTERISTICS over recommended operating conditions, all values are for open loop operation, IMOD m A, IBIAS m A, and RRZTC kΩ, unless otherwise...
Page 11 ONET4291VA www.ti.com SLLS674–SEPTEMBER AC ELECTRICAL CHARACTERISTICS (continued) over recommended operating conditions with 50-Ω output load, open loop operation, IMOD m A, IBIAS m A, and RRZTC kΩ (u...
Page 12 ONET4291VA www.ti.com SLLS674–SEPTEMBER an itt er ia s- ito rr en t − TYPICAL CHARACTERISTICS Typical operating condition is at VCC 3.3 and TA 25°C (unless otherwise noted) BIAS-MONITOR CURRENT IMONB ...
Page 13 ONET4291VA www.ti.com la tio rr en t − SLLS674–SEPTEMBER ra si tio im ps TYPICAL CHARACTERISTICS (continued) Typical operating condition is at VCC 3.3 and TA 25°C (unless otherwise noted) RISE-TIME AN...
Page 14 ONET4291VA www.ti.com SLLS674–SEPTEMBER in le -E ed tp t V lta /D iv in le -E ed tp t V lta /D iv TYPICAL CHARACTERISTICS (continued) Typical operating condition is at VCC 3.3 and TA 25°C (unless othe...
Page 15 ONET4291VA www.ti.com SLLS674–SEPTEMBER APPLICATION INFORMATION Figure shows typical application circuit using the ONET4291VA with common cathode VCSEL connected to ground. The VCSEL driver is control...
Page 16 PACKAGE OPTION ADDENDUM www.ti.com 28-Sep-2005 PACKAGING INFORMATION Orderable Device Status Package Package Pins Package Eco Plan Lead/Ball Finish MSL Peak Temp Type Drawing Qty ONET4291VARGPR PREVIE...
Page 17 PACKAGE OPTION ADDENDUM www.ti.com 16-Jan-2006 PACKAGING INFORMATION Orderable Device Status Package Package Pins Package Eco Plan Lead/Ball Finish MSL Peak Temp Type Drawing Qty ONET4291VARGPR ACTIVE...
Page 21 IMPORTANT NOTICE Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, modifications, enhancements, improvements, and other changes to its products and servic...

Manual Details

Brand Texas Instruments
Pages 21
File Size 580.58 KB
Published June 20, 2026
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Frequently Asked Questions

What is the maximum operating temperature range for this device?

It is characterized for operation from –40°C to 85°C ambient temperature.

How does the ONET4291VA provide digital control over current settings?

The modulation and bias currents are digitally controlled via a 2-wire interface, eliminating the need for external components.

What voltage supply is required to power the VCSEL driver?

The device requires a single 3.3-V supply.

Does the ONET4291VA include safety or optimization features?

Yes, it includes an automatic power control (APC) loop and circuitry to support laser safety and transceiver management systems.