Products Description

Technical Specs Summary

Parameter	Specification
TX OEM Reference	Avago (Broadcom) AFBR-1531CZ → GIGAC DT-1531 (gray housing)
RX OEM Reference	Avago (Broadcom) AFBR-2531CZ → GIGAC DT-2531 (black housing)
Wavelength	520nm (visible green LED)
Fiber Type	Standard 1mm plastic optical fiber (POF)
Data Rate	DC to 5MBd
Transmission Distance	Up to 270 meters at 5MBd over 1mm POF
Receiver	Internal PINPD + integrated circuit with TTL output
TX Output	Optical (LED drive)
RX Output	TTL (positive or negative — selectable)
Operating Temperature	–40°C to +85°C
Form Factor	Various configurations available
Housing Colors	Transmitter: Gray \| Receiver: Black
Standards	MIL-STD-883 Method 3015 \| IEC 60825-1, 2 Class 1 \| RoHS
Applications	Industrial control \| Power supply \| High-voltage isolation \| RS232/RS485 \| LAN

Detailed Product Description

Product Overview

The GIGAC DT-1531/2531 Series is a plastic optical fiber (POF) transmitter and receiver module combination designed for short-distance, interference-resistant data communications in industrial environments. It is fully compatible with the Avago (now part of Broadcom) AFBR-1531CZ/AFBR-2531CZ series modules, leveraging POF technology to balance performance and cost for short-distance data transmission in high-noise environments.

The AFBR-1531CZ is the transmitter module and the AFBR-2531CZ is the corresponding receiver module — they work in tandem and must be deployed as a matched pair for a complete optical link. The transmitter uses an internal 520nm wavelength LED (visible green light), while the receiver integrates a PINPD with TTL output circuitry. The 520nm visible green emission is unique in this product series — unlike all other GIGAC optical modules that operate in the near-infrared (820–1550nm), this module emits visible light that can be seen with the human eye.

The module is an ideal choice for communication solutions in industrial manufacturing, transportation, and other fields where its design balances robustness and ease of use, making it a reliable bridge in electrical isolation scenarios. Certified to MIL-STD-883 Method 3015, IEC 60825-1,2 Class 1, and RoHS standards.

TX / RX Module Pairing Reference

The AFBR-1531CZ and AFBR-2531CZ are separate modules — always order one of each for a complete link.

	Transmitter Module	Receiver Module
Avago OEM Part	AFBR-1531CZ	AFBR-2531CZ
GIGAC Compatible	DT-1531	DT-2531
Housing Color	Gray	Black
Function	TX only (LED transmitter)	RX only (PIN + TTL output)
Wavelength	520nm (green visible)	Receives 520nm
Output	Optical output	TTL signal output (pos. or neg.)

TX (gray) connects to the transmitting end of the fiber; RX (black) connects to the receiving end. The TTL output polarity (positive or negative) is selectable on the receiver module.

Key Features

520nm visible green LED transmitter — detectable by the human eye

1mm plastic optical fiber (POF) — rugged, flexible, low-cost

DC to 5MBd data rate — full industrial serial speed coverage

Up to 270m transmission distance over standard 1mm POF

Internal PINPD + integrated TTL output circuit in receiver

TTL output: positive or negative logic — selectable

Matched TX/RX pair: Gray transmitter (DT-1531) + Black receiver (DT-2531)

Operating temperature: –40°C to +85°C

Various form factor configurations available

MIL-STD-883 Method 3015 certified

IEC 60825-1, 2 Class 1 optical safety certified

RoHS compliant

Technical Advantages

520nm Visible Green — Visual Installation Verification

At 520nm, the LED emission falls in the human-visible green spectrum. Unlike near-infrared optical modules (820–1550nm) that emit invisible light, the 520nm LED output is directly visible to the eye — allowing installation technicians to visually confirm that the transmitter is operational and that the fiber is correctly aligned and coupled without requiring optical power meters or test equipment. This is a practical installation advantage in factory and field environments.

1mm Plastic Optical Fiber — Industrial Ruggedness and Cost

1mm POF (Plastic Optical Fiber) offers significant advantages over glass fiber in short-distance industrial applications: the large 1mm core diameter tolerates large fiber-to-connector misalignment, POF is mechanically flexible and resistant to breakage from bending, and POF connectors and patch cords are lower cost than glass fiber equivalents. POF is also immune to the fragility concerns of glass fiber in high-vibration environments such as motor drive cabinets and vehicle installations. Standard 1mm POF patch cords are widely available from industrial distributors.

High-Voltage Isolation — Galvanic Isolation for Power Electronics

Plastic optical fiber provides complete galvanic isolation between transmitter and receiver — there is no electrical path through the fiber, making it inherently immune to ground loop currents, common-mode voltages, and high-voltage transients on the power bus. At DC–5MBd rates, the module is suitable for control signal isolation across high-voltage barriers in power supply systems, motor drive gate drivers, and high-current switching circuits where ground potential differences can exceed kilovolts.

MIL-STD-883 Method 3015 — Military Reliability Qualification

MIL-STD-883 Method 3015 is the US military qualification test method for optical coupling devices and fiber optic interconnects. Certification to this standard demonstrates that the module has been tested for mechanical shock, vibration, temperature cycling, humidity, and electrostatic discharge to military-grade acceptance criteria. This makes the DT-1531/2531 appropriate for military ground support equipment, defense electronics, and other applications requiring documented military qualification.

TTL Output with Positive/Negative Logic Selection

The receiver module (DT-2531) provides TTL output with selectable positive or negative logic — allowing the received optical signal to be mapped to either active-high or active-low electrical signal conventions without additional inversion circuitry in the host system. This flexibility simplifies integration into diverse industrial PLC, DCS, and embedded controller I/O circuit designs.

Important: AFBR-1531CZ (DT-1531, gray) is the TRANSMITTER and AFBR-2531CZ (DT-2531, black) is the RECEIVER. They must be used as a paired set — one TX at the transmitting end, one RX at the receiving end. The modules are NOT interchangeable. Order one of each for each fiber link. Verify TTL output polarity requirement (positive or negative) before ordering.

Typical Applications

High-voltage isolation optical links (power supply, inverter control)

Industrial control and factory automation fiber serial links

RS232 and RS485 optical isolation over plastic optical fiber

Motor drive and servo controller control signal POF isolation

Power supply applications requiring galvanic isolation

Data communications and industrial LAN over POF

Military and defense electronics requiring MIL-STD-883 qualification

Transportation and vehicle-installed fiber communication links

Compatibility and Deployment

The DT-1531 (transmitter) and DT-2531 (receiver) are direct replacements for the Avago AFBR-1531CZ and AFBR-2531CZ. They share the same mechanical footprint and pinout, installing directly in any system designed for the Avago modules. Compatible fiber: standard 1mm plastic optical fiber (POF). Maximum link distance: 270m at 5MBd.

For deployment: connect the TX module (gray, DT-1531) at the data source end and the RX module (black, DT-2531) at the data destination end. Verify the TTL output polarity required by your receiving circuit and configure the RX module accordingly. Contact our technical team for form factor variants, MIL-STD documentation, or volume pricing.

FAQ Module

Q: What makes the AFBR-1531CZ different from other optical transceivers in this series?

A: The AFBR-1531CZ/2531CZ series has three unique characteristics not found in other modules: (1) 520nm visible green wavelength — you can see the light with the human eye, unlike all other modules in this series which use invisible near-infrared wavelengths. (2) 1mm plastic optical fiber (POF) instead of glass fiber. (3) Separate TX and RX modules that must be paired — the 1531CZ is transmitter-only and the 2531CZ is receiver-only.

Q: Why does this use 1mm plastic optical fiber instead of glass fiber?

A: 1mm POF offers key advantages in short-distance industrial applications: large 1mm core diameter tolerates significant fiber-connector misalignment; POF is mechanically flexible and resistant to bending damage; POF connectors and patch cords are lower cost; and POF is immune to the fragility of glass fiber in vibration-heavy environments. For distances up to 270m at 5MBd, POF provides a cost-effective and robust alternative to glass fiber.

Q: Do I need to order both the TX and RX module?

A: Yes — for a complete optical link you need one transmitter (AFBR-1531CZ / DT-1531, gray housing) at the source end and one receiver (AFBR-2531CZ / DT-2531, black housing) at the destination end. The modules are sold separately and are not interchangeable. Order one of each for each fiber link in your system.

Q: What is the MIL-STD-883 Method 3015 certification?

A: MIL-STD-883 Method 3015 is the US military test standard for optical coupling devices, covering mechanical shock, vibration, temperature cycling, humidity, and electrostatic discharge tests to military acceptance criteria. This certification is required for optical modules used in defense electronics, military ground support equipment, and government procurement applications requiring documented military qualification.

Q: What is the maximum transmission distance?

A: Up to 270 meters over standard 1mm plastic optical fiber (POF) at 5MBd. Actual maximum distance depends on fiber quality, connector condition, and accumulated optical losses. Using higher-quality POF patch cords and minimizing connector splices will maximize the achievable link distance.

Q: Can the TTL output logic be inverted?

A: Yes. The DT-2531 receiver module TTL output supports both positive and negative logic — the output polarity can be configured to match the active-high or active-low convention required by the receiving circuit. This eliminates the need for an external inverter stage in the host system.