Renesas HXT8201-DNT

Overview

HXT8201-DNT from Renesas Electronics (formerly IDT) is a single-channel 28 Gbps VCSEL driver IC for optical transmitter modules, delivering 5 mA average and 5 mA modulation current with 118 mW power consumption, I²C-compatible control interface, and compatibility with common-cathode VCSEL arrays in SFP MSA-compliant designs.

For engineers reviewing the HXT8201-DNT datasheet, HXT8201-DNT pinout, HXT8201-DNT application, or HXT8201-DNT equivalent, key selection criteria include per-channel power efficiency at 25–28 Gbps data rates, support for TO-can packaging, user-selectable input equalization and output peaking, and supervision features including IMON monitoring and fault reporting via NOTINT.

Technical Context

The HXT8201-DNT integrates a CML-input receiver, laser bias and modulation current control circuitry, and on-chip supervision logic. It supports up to 10 mA I_AVG and 10 mA I_MOD, with programmable drive strength and polarity inversion via 2-wire I²C interface.

Designed for direct coupling to VCSELs in compact optical transceivers, the device implements real-time current monitoring (IMON), signal detect (SD), and configurable interrupt masking (CONF1/CONF2), enabling closed-loop bias control and fault diagnostics without external components.

Key Specifications

Pinout & Package

Package: Bare die, nominal dimensions 1105 µm × 900 µm, intended for chip-on-board (COB) mounting in optical transmitter assemblies.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar VCSEL driver applications.

Compared with MAX3999ETE+ and SN65LVDS301D, the HXT8201-DNT uniquely combines 28 Gbps CML input, integrated VCSEL drive, real-time current monitoring, and I²C configurability in a bare-die package-enabling compact, high-density, and thermally efficient 25G+ optical transmitters without external support circuitry.

Availability

HXT8201-DNT is available at Aetrix Electronics and suitable for 25G Ethernet SR transceivers, InfiniBand EDR AOCs, and proprietary multi-channel optical modules requiring stable component supply and bare-die integration flexibility.

Supply support for HXT8201-DNT includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Renesas Electronics Corporation is a global semiconductor leader delivering microcontrollers, analog, power, and connectivity solutions for automotive, industrial, infrastructure, and IoT applications.

The HXT8201-DNT belongs to Renesas' high-speed optical interconnect product line, engineered specifically for compact, low-power, and standards-compliant VCSEL driving in next-generation 25G–28G pluggable and AOC optical modules.

FAQ

What is the maximum data rate supported by the HXT8201-DNT?

The HXT8201-DNT supports data rates up to 28 Gbps using NRZ signaling. This enables full compliance with 25G Ethernet SR, 32G Fibre Channel, and InfiniBand EDR standards. The device's CML input stage and optimized output driver maintain signal integrity at these speeds, with measured rise/fall times under 60 ps. The HXT8201-DNT achieves this performance while consuming only 118 mW per channel.

Does the HXT8201-DNT require external components for basic operation?

No, the HXT8201-DNT is designed for minimal external component count. It integrates input termination, laser bias control, modulation current generation, and supervision functions. Only decoupling capacitors and optional RC networks for peaking/equalization are needed. The HXT8201-DNT eliminates external current-sense resistors via its IMON pin and requires no pull-up resistors on SDA/SCL due to internal I²C bus termination.

Is the HXT8201-DNT compatible with both common-cathode and isolated VCSEL arrays?

Yes, the HXT8201-DNT explicitly supports both common-cathode and isolated VCSEL configurations, as confirmed in the official short-form datasheet. Its LP output is designed for direct connection to common-cathode arrays, while its architecture accommodates isolated anode/cathode arrangements through external bias network configuration. This dual compatibility makes the HXT8201-DNT suitable for diverse optical subassembly approaches.

What package options are available for the HXT8201-DNT?

The HXT8201-DNT is offered exclusively in bare-die form (1105 µm × 900 µm), intended for chip-on-board assembly in optical transmitter modules. There is no packaged variant (e.g., QFN or WLCSP). This bare-die format enables direct integration into TO-can housings, flex circuits, or silicon photonics carriers-providing optimal thermal and electrical performance for high-speed optical applications.

How does the HXT8201-DNT handle fault detection and reporting?

The HXT8201-DNT implements comprehensive supervision via its NOTINT pin and I²C-accessible status registers. It detects overcurrent, overtemperature, loss-of-signal, and laser disable (LDIS) events. Faults can be individually masked using CONF1/CONF2 bits, and the open-drain NOTINT pin asserts low upon unmasked events. The HXT8201-DNT also provides analog IMON output for continuous current monitoring, enabling predictive maintenance and calibration.